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UBC Theses and Dissertations

Mode choice determiniants of selected socioeconomic groups : an investigation of a planning and control… Brown, Gerald Richardson 1971

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MODE CHOICE DETERMINANTS OF SELECTED SOCIOECONOMIC GROUPS: AN INVESTIGATION OF A-PLANNING AND CONTROL MECHANISM TO DIVERT AUTOMOBILE DRIVERS TO PUB L I C TRANSPORTATION by GERALD RICHARDSON ^BROWN B . S c , Queen's U n i v e r s i t y , 1956 M . S c , U n i v e r s i t y o f B r i t i s h C o l u m b i a , 1966 A THESIS SUBMITTED I N PA R T I A L FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n I n t e r d i s c i p l i n a r y S t u d i e s ( T r a n s p o r t a t i o n ) i n t h e D e p a r t m e n t o f Community and R e g i o n a l P l a n n i n g We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d THE UNIVERSITY OF A p r i l , B R I T I S H COLUMBIA 1971 I n p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r a n a d v a n c e d d e g r e e a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e a n d s t u d y . I f u r t h e r a g r e e t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by t h e H e a d o f my D e p a r t m e n t o r by h i s r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . D e p a r t m e n t o f Community Planning T h e U n i v e r s i t y o f B r i t i s h C o l u m b i a V a n c o u v e r 8, C a n a d a D a t e April 27, 1971 ABSTRACT This study examines the determinants of i n d i v i d u a l commuter mode c h o i c e , and the f e a s i b i l i t y of a d j u s t i n g the mode s p l i t by p u b l i c p o l i c y ; with s p e c i a l • r e f e r e n c e to changes i n p a r k i n g arrangements and the p r i c e of-.parking. Hypotheses about the dimensions of t r a v e l time, c o s t , comfort, and con-venience i n the mode ch o i c e d e c i s i o n f o r v a r i o u s socioeconomic s t r a t a are formulated from an examination of a s i n g l e t r a v e l c o r r i d o r i n Vancouver, Canada. A dis a g g r e g a t e s t o c h a s t i c b e h a v i o r a l model of t h e . d i s c r i m i n a t i o n - c l a s s i f i c a t i o n type i s developed and used to t e s t the hypotheses w i t h i n the context of a p l a n n i n g and c o n t r o l mechanism based on p o l i c y changes. The r e s u l t s i n d i c a t e t h a t ad jus tmentsj in . r e s i d e n t i a l t r a v e l time, p a r k i n g charges, and^bus^fr1eq.uency.,.would. be. most e f f e c -t i v e i n changing mode s p l i t . A second s e r i e s of t e s t s measured the p r o p e n s i t y of d i f f e r e n t socioeconomic groups to s h i f t from automobile t r a v e l to a multimode "park and r i d e " system. A s o - c a l l e d " p r o p e n s i t y " model was formulated from i n d i v i d u a l p r e f e r e n c e s f o r the s e r - 1 v i c e c h a r a c t e r i s t i c s r e q u i r e d to encourage a s h i f t to the multimodal system; o r a change i n downtown p a r k i n g c o s t to e f f e c t a s h i f t to t r a n s i t . The p r o p e n s i t y model i n d i c a t e s t h a t s u b s t a n t i a l ; s h i f t s c o u l d be expected w i t h l a r g e percentage i n c r e a s e s i n p a r k i n g charges i n c o n j u n c t i o n w i t h improvements i n t r a n s i t s e r v i c e . To be e f f e c t i v e i n promoting mode s h i f t the park and r i d e s e r v i c e would r e q u i r e very e f f i c i e n t t r a n s -f e r arrangements a t t h e . f r i n g e t e r m i n a l , and fr e q u e n t t r a n s i t s e r v i c e . The s t a t i s t i c a l t e s t s demonstrate t h a t p r o p e n s i t y to s h i f t i s r e l a t e d to the socioeconomic c h a r a c t e r i s t i c s of the tripmaker. Those under 40, from s i n g l e c a r f a m i l i e s , with middle-to lower incomes, and .those i n the n o n - p r o f e s s i o n a l occupations have h i g h e r p r o p e n s i t y to s h i f t than the popula-t i o n as a whole. The study i s conducted w i t h i n the context of a phil o s o p h y of t r a n s p o r t a t i o n p l a n n i n g which seeks to channel demand f o r t r a n s p o r t a t i o n s e r v i c e s toward community.objectives. The r e s u l t s are antecedents of a p l a n n i n g and c o n t r o l mechanism which i s both g o a l - o r i e n t e d and-incremental; i n c o r p o r a t i n g both system planning.and d e c i s i o n making i n the long term context, and f l e x i b l e o p e r a t i o n a l c o n t r o l o f the system to meet s h o r t term o b j e c t i v e s . The mechanism suggested, u s i n g p a r k i n g p o l i c y as the c o n t r o l f a c t o r , i s aimed a t in c r e m e n t a l investment d e c i -s i o n s which a r e m o r e ' o r l e s s r e v e r s i b l e . I t i s concluded t h a t p a r k i n g p o l i c y changes, i f the i n s t i t u t i o n a l s e t t i n g a l l o w s , can be an e f f e c t i v e g o a l o r i e n t e d instrument f o r mode s p l i t p l a n n i n g . TABLE OF CONTENTS CHAPTER Page I. INTRODUCTION 1 The Problem 1 O u t l i n e of Research 12 I I . CONCEPTUAL BACKGROUND 16 I n f l u e n c e of Urban Socioeconomic S t r u c t u r e on Mode S p l i t 17 I n f l u e n c e o f T r a n s p o r t a t i o n S e r v i c e on Mode S p l i t 24 Behavior Models 34 Needs of a New Approach 42 Research Assumptions 47 I I I . DESCRIPTIVE ANALYSIS OF CASE STUDY 53 Data P r e p a r a t i o n 53 Mode S p l i t and the Socioeconomic S t r u c t u r e of Commuters 60 Behavior P r o f i l e s of Modal Group 73 P r i n c i p a l F i n d i n g s 100 IV. MULTIVARIATE ANALYSIS OF INTERMODAL DEMAND 10 6 P r e p a r a t i o n of Data M a t r i x 106 Interdependence o f Socioeconomic S t r u c t u r e and System Performance 117 C l a s s i f i c a t i o n of Modal S p l i t on Combined F a c t o r s 13 0 Mode Choice as a F u n c t i o n of P o l i c y V a r i a b l e s 153 Comparative A n a l y s i s of R e s u l t s 159 P r i n c i p a l F i n d i n g s 163 i i i CHAPTER Page V. PROPENSITY OF CAR DRIVERS TO SHIFT MODE 166 Mode S p l i t P l a n n i n g O b j e c t i v e s 166 O u t l i n e of the S h i f t P r o p e n s i t y Model 169 S h i f t P r o p e n s i t y of North Shore Commuters 179 I n f l u e n c e of Socioeconomic C h a r a c t e r i s t i c s i n Mode S h i f t P r o p e n s i t y 194 P r i n c i p a l F i n d i n g s 219 VI. MAJOR CONCLUSIONS, IMPLICATION OF FINDINGS, AND FURTHER RESEARCH 2 24 In c i d e n c e of E f f e c t s of Mode S h i f t P o l i c i e s 226 P u b l i c I n t e r e s t B e n e f i t s and System Performance 231 P a r k i n g P o l i c y as an Incremental C o n t r o l , Mechanism 233 The P r o p e n s i t y Model 240 New T e c h n o l o g i c a l F a c t o r s i n Mode S p l i t P l a n n i n g 241 L i m i t a t i o n s of Study and F u r t h e r Research 24 4 REFERENCES 249 BIBLIOGRAPHY 264 APPENDICES A. Study Region 27 5 B. Sample Q u e s t i o n n a i r e 276 C. Computer Program f o r Data C o n v e r s i o n 279 D. Computer Program f o r Score M a t r i x 1 283 E. Computer Program f o r S t a n d a r d i z i n g Score M a t r i x 1 285 F. Ma x i m i z a t i o n of C o r r e l a t i o n Between L i n e a r Set U and V 286 i v Page G. Geometric I l l u s t r a t i o n of A x i s R o t a t i o n and V e c t o r s v 288 H. Computer Program f o r Score M a t r i x 2 290 v LIST OF TABLES TABLE Page I Chi-square Contingency T e s t of Car Sample V a l i d i t y 59 II P e r c e n t of each Socioeconomic Group Commuting to C e n t r a l Business D i s t r i c t L o c a t i o n s Compared to Other D e s t i n a t i o n s , By Car and By Bus 61 I I I S i g n i f i c a n c e T e s t of Socioeconomic Charac-t e r i s t i c s of CBD Commuters Versus Non-CBD Commuters 6 2 IV S i g n i f i c a n c e T e s t of Socioeconomic Charac-t e r i s t i c s of Car Users Versus T r a n s i t R i d e r s 65 V T o t a l T r a v e l Time by Mode 76 VI Mean T o t a l T r a v e l Time by Income Category and Mode 7 8 VII Mean T o t a l T r a v e l Time by O c c u p a t i o n a l Category and Mode 81 V I I I R e l a t i v e T r a v e l Time by Bus Compared to That By Car, f o r Car and Bus A l t e r n a t i v e 83 IX P a r k i n g Charge a t CBD D e s t i n a t i o n 88 X P a r k i n g Charge by Income Category 89 XI P a r k i n g Charge by Oc c u p a t i o n Category 90 XII T e r m i n a l Time a t O r i g i n by Mode 91 XI I I O u t - o f - v e h i c l e Times f o r Bus Passengers 93 XIV T e r m i n a l Time a t D e s t i n a t i o n by Mode 94 XV Percentage of Those Going by Car i n Each Walking D i s t a n c e Category from P a r k i n g Lo t to F i n a l D e s t i n a t i o n , by Income and Occupation 95 XVI C a n o n i c a l C o r r e l a t i o n T e s t f o r Auto D r i v e r Group 125 v i TABLE XVII XVIII XIX C a n o n i c a l C o r r e l a t i o n T e s t f o r Bus Group M a t r i x of Simple I n t e r c o r r e l a t i o n s of Socioeconomic and Behavior V a r i a b l e s f o r Car Group and T r a n s i t Group Group Means and Standard D e v i a t i o n s of Modal Groups f o r Combined Socioeconomic and Performance V a r i a b l e s • XX S t a t i s t i c a l T e s t s of S i g n i f i c a n c e f o r D i s c r i m i n a t i o n o f Modes on Combined Socioeconomic and Performance V a r i a b l e s XXI C e n t r o i d s of Modal Groups i n Reduced Space and S i g n i f i c a n c e T e s t of Group S e p a r a t i o n on Combined Socioeconomic and Performance V a r i a b l e s XXII D i s c r i m i n a t o r V e c t o r Loadings on Combined Socioeconomic and Performance V a r i a b l e s XXIII C o r r e l a t i o n M a t r i x of Combined S o c i o -economic and Performance V a r i a b l e s XXIV Group Means and Standard D e v i a t i o n s f o r Modal Groups on P o l i c y V a r i a b l e s XXV S t a t i s t i c a l T e s t s of S i g n i f i c a n c e f o r D i s c r i m i n a t i o n of Modes on S i x P o l i c y V a r i a b l e s XXVI V e c t o r Loadings on P o l i c y D i s c r i m i n a t o r Using S i x V a r i a b l e s XXVII P r e d i c t e d C l a s s i f i c a t i o n Versus A c t u a l Mode Used f o r F i v e P o l i c y V a r i a b l e s XXVIII Comparison of R e s u l t s of D i s c r i m i n a n t -C l a s s i f i c a t i o n A n a l y s i s of Mode Choice f o r Car and T r a n s i t Samples w i t h Three P r e v i o u s S t u d i e s XXVIIIa Means and Standard D e v i a t i o n s f o r Car Group and S h i f t Group, f o r a Proposed Park and Ride, and an Increa s e i n P a r k i n g Charges XXIX S t a t i s t i c a l T e s t s on P r o p e n s i t y of Mode S h i f t f o r the Car Group and S h i f t Group f o r a Proposed Multimodal System and f o r a T r a n s i t System Based on I n c r e a s e d P a r k i n g Charges Page 126 128 146 147 148 149 151 154 156 157 159 160 183 186 v i i 1 TABLE XXX Ve c t o r Loadings on D i s c r i m i n a t o r s XXXI C o r r e l a t i o n M a t r i c e s f o r Car Group and S h i f t Group on Multimodal V a r i a b l e s XXXII S i g n i f i c a n c e of D i s c r i m i n a t o r Using Only Those V a r i a b l e s Remaining S i g n i f i c a n t i n the Stepwise Procedure XXXIII P r e d i c t e d C l a s s i f i c a t i o n Versus A c t u a l Group Membership f o r the T e s t on the Multimodal System and the T r a n s i t System XXXIV C a n o n i c a l T e s t s of Independence of P r e f e r r e d A t t r i b u t e s w i t h A c t u a l Ones XXXV Age Group Means and Standard D e v i a t i o n s f o r Those Under 40 and Those Over 40 XXXVI S t a t i s t i c a l T e s t s of the P r o p e n s i t y of Age Groups t o S h i f t Mode XXXVII V e c t o r Loadings on D i s c r i m i n a t o r XXXVIII S i g n i f i c a n c e of D i s c r i m i n a t o r Using Only S i g n i f i c a n t V a r i a b l e s XXXIX P r e d i c t e d C l a s s i f i c a t i o n Versus A c t u a l Group Membership f o r Under 40 and Over 40 XL Car vOwnership Group Means and Standard D e v i a t i o n s f o r Car Ownership C a t e g o r i e s XLI S t a t i s t i c a l T e s t s of the P r o p e n s i t y o f Car Ownership Groups to S h i f t Mode XLII V e c t o r Loadings on D i s c r i m i n a t o r XLIII P r e d i c t e d C l a s s i f i c a t i o n Versus A c t u a l Group Membership XLIV S i g n i f i c a n c e of D i s c r i m i n a t o r Using Only S i g n i f i c a n t V a r i a b l e s XLV T e s t s on Car Ownership Using Three Groups XLVI Income Group Means and Standard D e v i a t i o n f o r Very Low, Low, Medium and High Income C a t e g o r i e s Page 187 189 189 192 197 198 199 199 200 202 203 204 204 205 206 208 v m TABLE XLVII XLVIII XLIX L LI L I I LI 11 LIV LV LVI LVII S t a t i s t i c a l T e s t of the P r o p e n s i t y of Income Groups t o S h i f t Mode V e c t o r Loadings on D i s c r i m i n a t o r s S i g n i f i c a n c e of Group S e p a r a t i o n S i g n i f i c a n c e o f D i s c r i m i n a t o r s Using Only S i g n i f i c a n t V a r i a b l e s P r e d i c t e d C l a s s i f i c a t i o n Versus A c t u a l Group Membership Occupation Group Means and Standard Devia-t i o n s f o r Managers, P r o f e s s i o n a l s , S e c r e t a r y , C l e r i c a l , S a l e s and Other O c c u p a t i o n a l C a t e g o r i e s S t a t i s t i c a l T e s t s of the P r o p e n s i t y of O c c u p a t i o n a l Groups to S h i f t Mode V e c t o r Loadings on D i s c r i m i n a t o r s S i g n i f i c a n c e of Group S e p a r a t i o n P r e d i c t e d C l a s s i f i c a t i o n Versus A c t u a l Group Membership S i g n i f i c a n c e o f D i s c r i m i n a t o r s Using Only S i g n i f i c a n t V a r i a b l e s Page 210 211 211 212 212 214 215 216 217 218 218 i x LIST OF FIGURES FIGURE Page 1. Sex C h a r a c t e r i s t i c s of Commuters to CBD by Mode Used 66 2. Age C h a r a c t e r i s t i c s of Commuters to CBD by Mode Used 67 3. O c c u p a t i o n a l C h a r a c t e r i s t i c s of Commuters to CBD by Mode Used 69 4. Car Ownership C h a r a c t e r i s t i c s o f Commuters to CBD by Mode Used 7 2 5. Income C h a r a c t e r i s t i c s of Commuters to CBD by Mode Used 74 6. L o c a t i o n of A x i s t o Maximize Between to W i t h i n Group V a r i a n c e f o r O b s e r v a t i o n C l u s t e r s A and B - Geometric I l l u s t r a t i o n o f Two Group, Two V a r i a t e Case 139 7. I n d i f f e r e n c e Curve I l l u s t r a t i n g D i s u t i l i t y of Combinations of Time and Cost of Two Modes f o r a H y p o t h e t i c a l I n d i v i d u a l k 173 8. C l u s t e r s of Ob s e r v a t i o n s on R e l a t i v e D i s u t i l i t y Values f o r I n d i v i d u a l s of Two H y p o t h e t i c a l Socioeconomic Groups 175 x ACKNOWLEDGEMENT The author wishes t o thank the members of h i s program committee; V.S. Pendakur, T.D. Heaver, R.U. R a t c l i f f , E.M. Horwood, H.P. Oberlander, W.G. Hardwick and R.G. Hennes f o r t h e i r guidance and counsel as t e a c h e r s , and d u r i n g the course of t h i s i n v e s t i g a t i o n . The author wishes a l s o to thank Mr. John Harding of the B r i t i s h Columbia Highways Department, and Mr. A.. Andrews and h i s s t a f f ~at N.D. Lea and A s s o c i a t e s f o r t h e i r c o o p e r a t i o n i n s u p p l y i n g data f o r the study. Any misuse o r m i s i n t e r p r e t a t i o n of the data i s the s o l e r e s p o n s i b i l i t y of the author. x i CHAPTER I INTRODUCTION The Problem The growth of automobile t r a f f i c a f t e r the Second World War r e s u l t e d i n an i n c r e a s e d demand f o r b e t t e r roads i n urban r e g i o n s . T h i s t r e n d has been accompanied by a s t e a d i l y d e c l i n i n g demand f o r p u b l i c t r a n s p o r t a t i o n . Consequently, the proc e s s known as urban t r a n s p o r t a t i o n p l a n n i n g e v o l v e d primar-i l y as a means to analyze and e x t r a p o l a t e the demand f o r roads and automobile o r i e n t e d support f a c i l i t i e s . Meeting the demand f o r roads has however produced some severe n e g a t i v e s o c i a l consequences and has r e s u l t e d i n a r e c e n t concern with the need to r e v i t a l i z e t r a n s i t s e r v i c e s . T h i s n e c e s s i t a t e s new approaches to t r a n s p o r t a t i o n p l a n n i n g and d e c i s i o n making which go beyond the simple e x t r a p o l a t i o n of e x i s t i n g demand p a t t e r n s and which i n c o r p o r a t e s o c i e t a l o b j e c t i v e s i n t o the a n a l y s i s o f demand f o r t r a n s p o r t a t i o n s e r v i c e s . One such approach i s the study of c o n t r o l mechanisms which can be used f o r p u b l i c i n t e r v e n t i o n and adjustment of the balance between the v a r i o u s t r a n s p o r t a -t i o n modes. T h i s r e s e a r c h i s an i n v e s t i g a t i o n o f the d e t e r -minants of mode c h o i c e and p r e f e r e n c e s of s e l e c t e d socioeconomic groups, and an examination of the r o l e of p a r k i n g p o l i c y as a c o n t r o l mechanism to a d j u s t the modal s p l i t . 2. There have been many su g g e s t i o n s f o r t e c h n o l o g i c a l changes i n t r a n s p o r t a t i o n modes, along w i t h a r e - e v a l u a t i o n of more t r a d i t i o n a l forms of p u b l i c t r a n s p o r t a t i o n to change the modal s p l i t . But experi e n c e has shown t h a t t r a d i t i o n a l forms of p u b l i c mass t r a n s i t modes have not been w i d e l y accep-t e d by the p u b l i c as an a l t e r n a t i v e to automobile t r a v e l . T h i s has r e s u l t e d i n d e c l i n i n g revenues and subsequent dec-reases i n s e r v i c e . Yet, a r a t i o n a l i z a t i o n of urban t r a n s p o r - • t a t i o n s e r v i c e s i s e x p l i c i t l y bound up i n the n o t i o n o f a t r a n s p o r t a t i o n system i n which t h a t mix of d i f f e r e n t types of s e r v i c e i s found which maximizes community w e l f a r e . A p l a n n i n g and d e c i s i o n framework t o r a t i o n a l i z e the system has two major requirements: a complete u n d e r s t a n d i n g of the dimensions of demand f o r t r a n s p o r t a t i o n s e r v i c e s , and a c o n t r o l mechanism to a d j u s t the mode s p l i t i n accordance with p u b l i c o b j e c t i v e s . I f r a t i o n a l i z i n g the mode s p l i t means r e l a t i v e l y more use of t r a n s i t , a d j u s t i n g the mode s p l i t i s i n p r a c t i c e c r e a t i n g a s h i f t from c a r use to t r a n s i t use. For e -c a s t s are i n v a r i a b l y p e s s i m i s t i c r e g a r d i n g any l a r g e s h i f t o f commuters from automobiles. However, s e v e r a l aspects of these f o r e c a s t s are important to c o n s i d e r . F i r s t , even i f o n l y a very few c a r d r i v e r s s h i f t t o t r a n s i t t h e r e w i l l be a m u l t i -p l i e r e f f e c t on r e l i e v i n g c o n g e s t i o n s i n c e one c a r o f f the s t r e e t i s more than e q u i v a l e n t t o the a d d i t i o n of one or two t r a n s i t passengers to the system. Secondly, t h e r e i s l i t t l e 3 . doubt t h a t c e r t a i n socioeconomic groups would have a h i g h p r o p e n s i t y to s h i f t mode i f t h e i r c o n d i t i o n s were met by new p o l i c i e s . These groups would c o n s i s t of those people who have l i t t l e c u l t u r a l or emotional attachment t o the automobile as such, but who would s e l e c t the mode p r o v i d i n g the b e s t s e r v i c e . F i n a l l y , we have very l i t t l e knowledge of the l i m i t s of changes needed i n a t r a n s i t system t o encourage a s h i f t s i n c e behavior on the system i s r e s t r i c t e d by e x i s t i n g s e r v i c e . Only r e c e n t l y have some e f f o r t s been d i r e c t e d toward an approach f o r a s s e s s i n g t r a n s i t patronage w i t h r a d i c a l changes i n t r a n s i t s e r v i c e . A c e n t r a l concept i n such an approach i s to r e l a t e demand f o r the v a r i o u s means of t r a n s p o r t a t i o n to s a t i s f a c t i o n gained from the a t t r i b u t e s o f the system r a t h e r than t o the mode a c t u a l l y used. The premise i s t h a t a t r a v e l l e r uses a p a r t i c u l a r mode because i t p r o v i d e s him with the most d e s i r -a b l e , or l e a s t u n d e s i r a b l e , combination of t r a v e l time, t r a v e l c o s t , comfort and convenience. I f the demand f o r each combina-t i o n of a t t r i b u t e s can be measured the e f f e c t of new combina-t i o n s of a t t r i b u t e s can be t e s t e d . I f the new combination d e f i n e s a p r a c t i c a l means of t r a n s p o r t a t i o n the change i n demand, i n terms of a s h i f t from the c a r to the new mode, can be p r e d i c t e d . T h i s depends upon a s h i f t i n demand p a t t e r n s when a combination of a t t r i b u t e s d e f i n i n g new p a r k i n g and l i n e h a u l arrangements i s c o n c e i v e d . 4 . These demand p a t t e r n s can be assessed by means of mathematical models of i n d i v i d u a l d e c i s i o n p r o c e s s e s . Models can be a u s e f u l means of p r e d i c t i n g probable e f f e c t s of v a r i o u s p o l i c y o p t i o n s on users of the t r a n s p o r t a t i o n system. A few r e c e n t l y formulated t r a v e l demand models appear to have good promise i n s i m u l a t i n g i n d i v i d u a l d e c i s i o n making. Recent de-mand models are d i s a g g r e g a t e d t o c o n s i d e r the t r a v e l d e c i s i o n s of an i n d i v i d u a l . They are a l s o s t o c h a s t i c i n t h a t they p r e -d i c t the p r o b a b i l i t y of an i n d i v i d u a l making a s p e c i f i c c h o i c e . P r o b a b i l i t y i s a s s i g n e d by the model on the b a s i s o f the ch a r a c -t e r i s t i c s of the c h o i c e of environment, or i n t h i s case, on the a t t r i b u t e s of the t r a n s p o r t a t i o n system. T r a n s p o r t a t i o n models have been r e l a t i v e l y s u c c e s s f u l i n e x p l o r i n g mode c h o i c e beha-v o i r . However, g i v e n the severe r e s t r i c t i o n s on t r a n s i t be-h a v i o r a l e x p e r i e n c e by poor or n o n - e x i s t e n t s e r v i c e a l o g i c a l next s t e p i s toward p r e f e r e n c e models, or those which model t r a v e l l e r p r e f e r e n c e s as opposed t o ex t a n t b e h a v i o r . With such a model i t would be p o s s i b l e to p r e d i c t the p r o b a b i l i t y o f an i n d i v i d u a l s h i f t i n g to a new mode i f h i s p r e f e r e n c e s f o r system performance were i n c o r p o r a t e d i n the new mode. A s h i f t from automobile commuting to commuting on some new system depends upon the p e r c e p t i o n of the system by the u s e r , and s p e c i f i c a l l y the r e l a t i v e a t t r a c t i v e n e s s of the com-b i n a t i o n s of a t t r i b u t e s a v a i l a b l e . O b v i o u s l y some users w i l l always favour those a t t r i b u t e s which are onl y a v a i l a b l e w i t h 5 . a u t o m o b i l e c o m m u t i n g , s u c h as p r i v a c y a n d p r e s t i g e . On t h e o t h e r h a n d i n d i v i d u a l s who h a v e a c h o i c e may o p t f o r t r a n s i t b e c a u s e o f i t s l o w f a r e o r n o n - e x i s t e n t p a r k i n g c o s t . P r e v i o u s r e s e a r c h i n d i c a t e s t h a t g r o u p s o f i n d i v i d u a l s r e a c t d i f f e r e n t l y t o v a r i o u s c o m b i n a t i o n s o f modes a n d t h e i r c h a r a c t e r i s t i c s a c c o r d i n g t o s o c i o e c o n o m i c s t a t u s . C o n s e q u e n t l y , u n l i k e p r e v i o u s demand m o d e l s w h i c h t r e a t t h e t r a v e l m a r k e t as ho m o g e n e o u s , new m o d e l s m u s t a c c o u n t f o r t h e v a r i a n c e i n s o c i o e c o n o m i c s t a t u s o f t h e t r i p m a k e r . The n e e d t o s t r a t i f y u s e r s o f t h e s y s t e m i n t o c l i e n t g r o u p s w i t h d i f f e r e n t s e n s i t i v e n e s s t o s y s t e m a t t r i b u t e s a n d c h a n g e s i n t h e s y s t e m i s now e v i d e n t . Sommers i n e x p r e s s i n g t h e n e e d f o r an e x p a n d e d mode c h o i c e t h e o r y w r i t e s : m a r k e t d i s a g g r e g a t i o n i s — c o n s i d e r e d e n d e m i c t o a v a l i d mode s p l i t m o d e l . 1 W h i l e some e c o n o m e t r i c m o d e l s h a v e b e e n d e s i g n e d t o m o d e l t h e e f f e c t o f s y s t e m c h a n g e s o n mode s p l i t , o n l y f r a g m e n t a r y a t t e m p t s e x i s t t o show d i f f e r e n t i a l e f f e c t s o n t h e v a r i o u s s e c -t o r s o f t h e u r b a n t r a v e l m a r k e t . F o r e x a m p l e , q u e s t i o n s u c h as w h e t h e r g i v e n p r i c e c h a n g e s w o u l d h a v e more i m p a c t o n l o w i n c o m e g r o u p s t h a n o n h i g h i n c o m e g r o u p s h a v e n o t b e e n s y s t e m a -t i c a l l y e x p l o r e d . C l e a r l y t h e e f f e c t o f s y s t e m c h a n g e s o n t h e mode c h o i c e o f d i f f e r e n t g r o u p s i s d e p e n d e n t u p o n t h e p e r c e i v e d 6. r e l a t i v e d i s u t i l i t y of the a t t r i b u t e s o f the modes a v a i l a b l e . T h i s i m p l i e s t h a t s u b j e c t i v e p r e f e r e n c e s , i f they can be r e l i -a b l y measured, can be used to understand dimensions of t r a n s -p o r t a t i o n demand. A t t i t u d e s , as m a n i f e s t e d by s t a t e d p r e f e r -ences ; b e h a v i o r ; and group c h a r a c t e r i s t i c s a l l i n t e r a c t i n mode c h o i c e d e c i s i o n s . As Sommer s t a t e s : Mode c h o i c e b e h a v i o r , — i s determined by t r a v e l l e r a t t i t u d e s toward mode ch a r a c -t e r i s t i c s and by p e r s o n a l — o r e n v i r o n -mental f a c t o r s . 2 The s t r a t e g y of measuring s u b j e c t i v e p r e f e r e n c e s i s p a r t i c u -l a r l y u s e f u l where poor t r a n s i t s e r v i c e e x i s t s . A need i s seen f o r t h i s s t r a t e g y i n t r a n s i t marketing. S i n c e i t i s the expres-sed aim of marketing t r a n s i t t o make t r a n s i t more d e s i r a b l e to c e r t a i n groups than the automobile, an un d e r s t a n d i n g o f what i t i s t h a t people v a l u e i n making t h e i r c h o i c e o f mode i s c r i t i c a l t o marketing s t r a t e g i e s . As e a r l y as 1962 the Bureau of P u b l i c Roads r e c o g n i z e d the need to study Why groups of people choose d i f f e r e n t means of urban t r a v e l under v a r i o u s c o n d i t i o n s and how t h e i r c h o i c e s would be a f f e c t e d by the q u a l i t y and c o s t of d i f f e r e n t kinds of p r i v a t e and p u b l i c t r a n s p o r t a t i o n . 3 Consequently, i t appears necessary to study p r e f e r e n c e p a t t e r n s f o r any f u l l u n d e r s t a n d i n g of mode c h o i c e and p o l i c i e s which would be s u c c e s s f u l i n changing mode s p l i t . 7 . The second requirement o f a p l a n n i n g and d e c i s i o n framework f o r system r a t i o n a l i z i n g i s a p l a n n i n g c o n t r o l mechanism t o implement mode s h i f t s . T h i s r e q u i r e s i n t u r n a change i n the concept of t r a n s p o r t a t i o n p l a n n i n g as p r a c -t i c e d i n the p a s t . B a s i c a l l y t h i s i m p l i e s a change from the t r a d i t i o n a l concept o f p l a n n i n g t o meet demand f o r automobile t r a v e l t o one of p l a n n i n g to channel demand i n accordance w i t h community o b j e c t i v e s . 4 Steger and Lakshmanan have o u t l i n e d the t r a d i t i o n a l p r o c e s s . They i s o l a t e f o u r sub-processes: g o a l i d e n t i f i c a t i o n , p o l i c y and p l a n d e s i g n , p l a n t e s t i n g , and p l a n e v a l u a t i o n . T h i s schema i s a f o r m a l i z a t i o n o f ' t h e p r a c t i c a l process which has evolved s i n c e about 1950 i n which an "end s t a t e " development p l a n or pl a n s were formulated and v a r i o u s a l t e r n a t i v e t r a n s -p o r t a t i o n plans were d e v i s e d , t e s t e d , e v a l u a t e d and u l t i m a t e l y r e s u l t e d i n a "best" p l a n t o achieve t r a n s p o r t a t i o n g o a l s . T h i s p r a c t i c a l p r o c e s s , e v o l v i n g as i t d i d i n response t o the growth of automobile t r a f f i c , has r e c o g n i z a b l e s h o r t -comings f o r p l a n n i n g mode s p l i t adjustment. Mode s p l i t i n t h i s schema i s a simple d i v i s i o n of gross t r a v e l demand i n t o those who use cars and those who use t r a n s i t . As such the pr o -cess c o n t a i n e d no mechanism to p l a n mode s p l i t but i s based on the e x t r a p o l a t i o n of e x i s t i n g mode s p l i t c o n d i t i o n s and thereby tended t o pe r p e t u a t e e x i s t i n g auto dominance. By simply 8 . p r o j e c t i n g demand t h e t r a n s p o r t a t i o n p l a n n e r i s n o t h i n g more t h a n a p a s s i v e o b s e r v e r and f o r e c a s t e r o f t r e n d s . The S t e g e r a n d L a k s h m a n a n schema g o e s f u r t h e r h o w e v e r a n d r e c o g n i z e s t h e a c t i v e r o l e o f t h e p l a n n e r i n c h a n g i n g t r e n d s . T hey w r i t e : An i n c r e a s i n g e m p h a s i s on p r o c e s s e s by w h i c h c h a n g e s a r e i n t r o d u c e d t h a t w i l l a f f e c t f u t u r e ( s i c ) c h a r a c t e r o f t h e c i t y a n d t h e e f f e c t i v e -n e s s w i t h w h i c h p e r s o n s a n d a c t i v i t i e s w i l l b e a b l e t o i n t e r a c t i n t h e f u t u r e h a s become e v i d e n t . 5 They s e e k t o do t h i s e i t h e r by a p r i c i n g s y s t e m o r some o t h e r s u c h r e l a t i v e l y a u t o m a t i c and i m p e r s o n a l r a t i o n i n g m e c h a n i s m . S u c h a d e v i c e r e q u i r e s t h e i d e n t i f i c a t i o n o f e a c h c o n t r o l v a r i a b l e t h a t c a n r e s p o n d t o p u b l i c p o l i c y . Thompson s u g g e s t s t h i s i s t h e m a t u r e s t a g e o f u r b a n t r a n s p o r t a t i o n p l a n n i n g , w h e r e t h e " t a c t i c s o f p r i c e m a k i n g " w o u l d l a r g e l y r e p l a c e t h e c u r r e n t l y u s e d c o s t a c c o u n t i n g a p p r o a c h . T h i s i m p l i e s a p l a n n i n g a n d c o n t r o l m e c h a n i s m t o 7 a d j u s t mode s p l i t . Thomas a n d S c h o f e r d e f i n e t h e p r o c e s s o f c o n t r o l as i n v o l v i n g T h o s e a c t i v i t i e s o r d e c i s i o n s i n t e n d e d t o r e s u l t i n s h o r t - t e r m c h a n g e s . 8 Thomas a n d S c h o f e r ' s d e f i n i t i o n o f p l a n n i n g i n t h i s c o n t e x t i s The s e t o f a c t i v i t i e s a s s o c i a t e d w i t h l o n g - t e r m s y s t e m d e c i s i o n s . 9 9. A p l a n n i n g a n d c o n t r o l m e c h a n i s m t h e r e b y i n c o r p o r a t e s b o t h s y s t e m p l a n n i n g a n d d e c i s i o n m a k i n g i n a l o n g t e r m c o n t e x t a n d f l e x i b l e o p e r a t i o n a l c o n t r o l o f t h e s y s t e m t o m e e t s h o r t t e r m o b j e c t i v e s . A v e r y h i g h d e g r e e o f i n t e r a c t i o n b e t w e e n t h e s e p r o c e s s e s i s n e c e s s a r y t o r a t i o n a l t r a n s p o r t a t i o n p l a n n i n g and d e c i s i o n m a k i n g . A d e c i s i o n p r o c e s s w h i c h h a s t h e a b o v e c h a r a c t e r i s -t i c s i s n e c e s s a r i l y d o m i n a t e d by a c e n t r a l p h i l o s o p h y o f p r o b -l e m s o l v i n g by i n c r e m e n t a l s t e p s . One s u c h p u b l i c d e c i s i o n m a k i n g p h i l o s o p h y i s " d i s j o i n t e d i n c r e m e n t a l i s m " ; a s t r a t e g y d i r e c t e d t o t h e i d e n t i f i c a t i o n a n d s o l u t i o n o f p r o b l e m s by i n c r e m e n t a l c h a n g e s f r o m t h e " s t a t u s q u o . " B r a y b r o o k e a n d L i n d b l o m d e s c r i b e i t as a " m a r g i n - d e p e n d e n t " m e c h a n i s m f o r s o l v i n g p r o b l e m s . " ^ T h e r e i s no g o a l a c h i e v e m e n t o r i e n t a t i o n i n t h e p h i l o s o p h y as d o c u m e n t e d , b u t S t e g e r and L a k s h m a n h a v e c o m b i n e d " d i s j o i n t e d i n c r e m e n t a l i s m " w i t h a " f o r w a r d - s e e k i n g " g o a l o r i e n t e d p r o c e s s f o r t h e d e v e l o p m e n t o f t r a n s p o r t a t i o n p l a n s . T h e i r p r o c e s s (1) m o d e l s t h e s y s t e m (2) i d e n t i f i e s p r o b l e m s (3) e s t a b l i s h e s p r o b l e m s o l v i n g s h o r t - t e r m o b j e c t i v e s a n d (4) g e n e r a t e s a l t e r n a t i v e s t r a t e g i e s o r p o l i c y c o n t r o l s t o g u i d e t h e m o d e l l e d e n v i r o n m e n t t o w a r d a s t a t e d s e t o f g o a l s . The c o m b i n a t i o n o f i n c r e m e n t a l p r o b l e m s o l v i n g w i t h i n a l o n g r a n g e p l a n n i n g c o n t e x t a p p e a r s t o h a v e m e r i t as a p h i l o s o p h i c a l b a s i s f o r mode s p l i t p l a n n i n g . 10. Two methods have been suggested as means to r e g u l a t i n g the flow of t r a f f i c i n the s h o r t run;, c o n g e s t i o n p r i c i n g p o l i c i e s and p a r k i n g p o l i c i e s ( i n c l u d i n g p r i c i n g c o n t r o l s ) . P r i c i n g to r e s t r i c t automobiles from congested areas has been most 11 12 f o r c e f u l l y advocated by Beesley and Roth. The concept i s based on m a r g i n a l c o s t p r i c i n g which means, as Beesley s t a t e s : c h a r g i n g v e h i c l e s 1 users a c c o r d i n g t o t h e i r l i a b i l i t y to cause c o n g e s t i o n to themselves and t o oth e r v e h i c l e s a t s p e c i f i c road l o c a -t i o n s , and thus deny access to users who v a l u e t h e i r own c o s t s p l u s those imposed on others.13 T h i s i n v o l v e s imposing a charge d i r e c t l y r e l a t e d to the l e n g t h of time and s e c t i o n o f road used, and to the l e v e l o f c o n g e s t i o n a t the time the charge i s l e v i e d . Although the economic argu-ments f o r r e s t r i c t i v e road p r i c i n g are i m p r e s s i v e very l i t t l e s p e c i f i c a t t e n t i o n has been g i v e n t o c o n g e s t i o n p r i c i n g and mode s p l i t . Roth suggests t h a t road p r i c i n g alone.would not encourage people t o use buses, but the bus system a l s o must be made a t t r a c t i v e i n c o n j u n c t i o n w i t h r e s t r i c t i v e measures. The major problem w i t h c o n g e s t i o n p r i c i n g i s a l a c k of any e f f e c t i v e technique t o meter and a d m i n i s t e r the charge f o r c o n g e s t i o n . T h i s would a l s o apply t o mode s p l i t adjustment. A more p r a c t i c a l and e a s i l y a d m i n i s t e r e d system may be to con-t r o l p a r k i n g p o l i c i e s . P a r k i n g charges have been c r i t i c i z e d as a mechanism f o r c o n g e s t i o n p r i c i n g because i t n e g l e c t s through t r a f f i c . T h i s c r i t i c i s m does not, however, apply to mode s p l i t adjustment s i n c e each t r i p has a common t e r m i n a t i n g 1 1 . p o i n t and adjustment i s e f f e c t e d to the mode used, not to whether or not the t r i p i s made. A v a i l a b l e evidence of s e n s i t i v i t y to p a r k i n g charges or taxes suggests t h a t a mechanism based on p a r k i n g c o n t r o l s would be s u c c e s s f u l i n a d j u s t i n g mode s p l i t ; on both c o n c e p t u a l and p r a c t i c a l grounds. However, such a mechanism sh o u l d i n c l u d e n o n - p r i c e f a c t o r s because o f the o v e r a l l s e n s i t i v i t y to time and comfort aspects o f system u s e r s . These i n c l u d e w a l k i n g time a t the d e s t i n a t i o n and p a r k i n g time as w e l l as p a r k i n g fees o r a p a r k i n g tax. I f the p a r k i n g scheme i s extended beyond the CBD to i n c l u d e a park and r i d e system, r e s i d e n t i a l times, o v e r a l l t r a v e l times, frequency of buses l e a v i n g the park and r i d e t e r m i n a l , bus f a r e s , and t r a n s f e r and w a i t i n g c h a r a c t e r i s -t i c s of the system are a l l c r i t i c a l to p l a n n i n g a r a t i o n a l i z e d system. A main advantage of such an approach i s i n i t s i n c r e -mental s t r a t e g y f o r p u b l i c d e c i s i o n - m a k i n g . Investment d e c i -s i o n s are usually, d e r i v e d e i t h e r through an a n a l y s i s of r e -source f l o w s ; or an a p p r a i s a l by c o s t - b e n e f i t a n a l y s i s i n which c o s t s and b e n e f i t s are i n e q u i v a l e n t s o c i a l u n i t s ( i . e . , u n i t s which i n c l u d e non-economic as w e l l as economic c o n s i d e r a t i o n s ) . In view of the low l e v e l u n d e r s t a n d i n g of the e f f e c t s of p o l i c y changes on demand, as w e l l as the i n d i r e c t e f f e c t s which accrue to s p a t i a l r e o r g a n i z a t i o n ; and the l a r g e l y u n s u c c e s s f u l attempts to i n c l u d e i n t a n g i b l e s and s o c i a l c o s t s i n t o the c o s t - b e n e f i t 12. formula, a procedure based on r e s o u r c e flows appears t o be needed. By t h i s i s meant the i n c r e m e n t a l adjustments to the system by o p e r a t i o n a l improvements o r s m a l l c a p i t a l p r o j e c t s and simultaneous o b s e r v a t i o n of the e f f e c t s on the system. I f r e s u l t s are not i n the d i r e c t i o n d e s i r e d to reach s o c i e t a l g o a l s , the next increment of r e s o u r c e i n p u t i s designed to c o r r e c t the p r e v i o u s m i s a l l o c a t i o n . T h i s i s not u n l i k e a p u b l i c p r i c i n g mechanism i n which revenues from p r i c i n g p o l i c y are r e t u r n e d to the system to m a i n t a i n a balance i n the r e s o u r c e flows i n accordance with s o c i a l g o a l s . T h i s r e s e a r c h examines some of the p o s s i b i l i t i e s and the r a m i f i c a t i o n s of p a r k i n g p o l i c y as a p l a n n i n g and c o n t r o l mechanism to a d j u s t mode s p l i t . OUTLINE OF RESEARCH The study examines mode c h o i c e d e c i s i o n s and p r e f e r -ences of s e v e r a l socioeconomic groups f o r the purpose of under-s t a n d i n g what type of system changes are needed f o r a modal s h i f t , and to what degree automobile commuters may be encour-aged to s h i f t mode. The q u e s t i o n t h a t i s b e i n g i n v e s t i g a t e d i s whether or not m u n i c i p a l p a r k i n g p o l i c i e s can be e f f e c t i v e l y used to change mode s p l i t . The method of i n v e s t i g a t i o n i s to c o n s t r u c t a s t a t i s t i c a l model c o n s i s t i n g o f i n s t r u m e n t a l v a r i -a b l e s which are m a n i f e s t p u b l i c p a r k i n g p o l i c i e s . In t h i s way s h i f t s i n flows between car and t r a n s i t modes can be i n v e s t i g a t e d t h r o u g h s i m u l a t i n g c h a n g e s i n p o l i c i e s b y c h a n g i n g t h e i n s t r u m e n t a l v a r i a b l e s o f t h e m o d e l . The c e n t r a l w o r k i n g h y p o t h e s i s o f t h e s t u d y i s t h a t i n d i v i d u a l c h o i c e o f t h e means o f t r a n s p o r t a t i o n t o w o r k i s a f u n c t i o n o f t h e p e r f o r m a n c e a t t r i b u t e s o f t h e t r a n s p o r t a t i o n s y s t e m a n d o f s o c i o e c o n o m i c c h a r a c t e r i s t i c s o f t h e u s e r . E a c h t r i p t a k e r w i l l c h o o s e t h a t mode f o r w h i c h t h e c o m b i n a t i o n o f s e r v i c e c h a r a c t e r i s t i c s m i n i m i z e s h i s t r a v e l d i s u t i l i t i e s . F u r t h e r m o r e , t h e c o m b i n a t i o n s o f s e r v i c e a t t r i b u t e s c h o s e n , o r p r e f e r r e d , w i l l g r o u p t h e m s e l v e s a c c o r d i n g t o t h e s o c i o -e c o n o m i c g r o u p s t o w h i c h t h e i n d i v i d u a l t r i p m a k e r b e l o n g s . The s y s t e m a t t r i b u t e s e x a m i n e d a r e t h o s e w h i c h a r e c o n c e p -t u a l l y i n c l u d e d i n p o t e n t i a l m u n i c i p a l p a r k i n g p o l i c i e s . R e s e a r c h p r o c e d u r e i s l a r g e l y a n e m p i r i c a l a n a l y s i s o f a c a s e s t u d y c o r r i d o r . D a t a f o r t h e i n v e s t i g a t i o n c o n s i s t o f a t y p e o f o r i g i n d e s t i n a t i o n s t u d y o f t r a f f i c a n d b u s p a s -s e n g e r s t r a v e r s i n g a m a j o r t r a v e l c o r r i d o r i n V a n c o u v e r , C a n a d a . The m e t h o d s s e l e c t e d f o r a n a l y s i s w e r e done s o w i t h a v i e w t o i n v e s t i g a t i n g f o u r s p e c i f i c q u e s t i o n s : (1) What a r e t h e m a j o r i n f l u e n c e s o f mode c h o i c e i n t h e c a s e s t u d y c o r r i d o r , a n d how do t h e s e c o m p a r e w i t h f i n d i n g s e l s e w h e r e ? (2) What i s t h e ' i n t e r d e p e n d e n c e o f t h e s o c i o e c o n o m i c s t r u c t u r e o f u s e r s a n d t h e s e r v i c e a t t r i b u t e s o f t h e mode u s e d ? 14. (3) C a n u s e r s o f t h e c o r r i d o r be c l a s s i f i e d i n t o two d i s t i n c t c l i e n t g r o u p s b a s e d o n t h e mode u s e d , a n d w h a t a r e t h e i n s t r u m e n t a l , o r p o l i c y , v a r i a b l e s w h i c h h a v e t h e l a r g e s t i n f l u e n c e i n s e p a r a t i n g t h e s e c l i e n t g r o u p s ? A nd a r e t h o s e i n f l u e n c e s p e r t a i n i n g t o a p a r k i n g p o l i c y s i g n i f i c a n t i n mode c h o i c e b e h a v i o r ? (4) Can s t a t i s t i c a l l y a g g r e g a t e d u t i l i t y f u n c t i o n s o f s t a t e d p r e f e r e n c e s f o r s y s t e m c h a n g e s be u s e d t o p r e d i c t t h e p r o p e n s i t y o f c a r d r i v e r s t o s h i f t t o a p a r k a n d r i d e s y s t e m , a n d w h a t i s t h e i n f l u e n c e o f s o c i o e c o n o m i c s t r u c t u r e o n a c a r d r i v e r ' s p r o p e n s i t y t o s h i f t mode? C o n c e p t u a l l y , t h e s t u d y i s t a x o n o m i c . T h a t i s , i n d i -v i d u a l s a r e c l a s s i f i e d a c c o r d i n g t o t h e i r p e r c e p t i o n o f t r a n s -p o r t a t i o n s e r v i c e a n d t h e v a l u e t h e y p l a c e o n d i f f e r e n t s e r v i c e a t t r i b u t e s o f t h e s y s t e m . S u f f i c i e n t r e s e a r c h h a s now b e e n done t o b e a b l e t o I d e n t i f y t h e m a j o r q u a n t i f i a b l e v a r i a b l e s a s s o c i a t e d w i t h mode c h o i c e . F r o m t h i s p a s t r e s e a r c h an a p r i o r i c l a s s i f i c a t i o n o f mode c h o i c e i n f l u e n c e s i s p o s s i b l e . I n t h i s s t u d y t h e a p r i o r i c l a s s e s a r e t e s t e d a c c o r d i n g t o t h e i m p o r t a n c e e a c h c l a s s a t t a c h e s t o t h e v a r i a b l e s d e f i n i n g s y s t e m p e r f o r m a n c e . I n t h i s way two a s p e c t s o f t r a v e l demand c a n be i n v e s t i g a t e d : s y s t e m p e r f o r m a n c e i n f l u e n c e s w h i c h t e n d t o d i f f e r e n t i a t e t h o s e who commute by c a r f r o m t h o s e by t r a n s i t , and those i n f l u e n c e s which tend to d i f f e r e n t i a t e c a r d r i v e r s i n t o socioeconomic groups a c c o r d i n g to t h e i r p r o p e n s i t y to s h i f t to a park and r i d e system. The d a t a are analysed by means of m u l t i v a r i a t e s t a t i s t i c a l p r o c e d u r e s . M u l t i v a r i a t e a n a l y s i s i s concerned w i t h a n a l y z i n g m u l t i p l e measurements t h a t have been made on a number of i n d i v i d u a l s i n which the m u l t i p l e v a r i a t e s are c o n s i d e r e d i n combinations, i e . as a system of v a r i a t e s . Two s p e c i f i c techniques are used i n the study: c a n o n i c a l c o r r e l a -t i o n a n a l y s i s to d e s c r i b e the fundamental interdependence of a s e t of s e l e c t e d socioeconomic v a r i a b l e s w i t h the system per-formance v a r i a b l e s ; and m u l t i p l e d i s c r i m i n a n t a n a l y s i s to t e s t the c l a s s i f i c a t i o n systems. CHAPTER I I CONCEPTUAL BACKGROUND A n a l y s i s of mode s p l i t i s a p a r t of the urban t r a n s -p o r t a t i o n p l a n n i n g process to measure and p r e d i c t t r a v e l demand. The p r o c e s s i s s u b d i v i d e d i n t o s t u d i e s of t r a v e l g e n e r a t i o n , t r i p d i s t r i b u t i o n , mode s p l i t , and t r i p assignment. Mode s p l i t s t u d i e s have ev o l v e d through t h r e e d i s t i n c t s t a g e s . The f i r s t s t u d i e s r e l a t e d t r a v e l demand to the s t r u c t u r a l c h a r a c t e r i s t i c s of g e o g r a p h i c a l zones d e l i n e a t e d by the a g g r e g a t i o n of s o c i o -economic and l a n d use phenomena. Mode s p l i t c o n s i s t e d of a d i v e r s i o n of the t o t a l t r i p s generated f o r each zone to the road system or to the t r a n s i t system. In these e a r l y s t u d i e s no account was taken of the e f f e c t s of the system on mode s p l i t . Second stage s t u d i e s were those which emphasized the system e f f e c t s , and t r e a t e d the a l t e r n a t i v e modes as i f they were competing f o r a share of the t o t a l t r a v e l market. C o m p e t i t i o n was on the b a s i s of the r e l a t i v e advantage of the modes w i t h r e g a r d to t r a v e l time, t r a v e l c o s t , comfort and convenience a t t r i b u t e s . The v a r i a b l e s d e s c r i b i n g the system a t t r i b u t e s were zonal averages and t h e r e f o r e were not analogous to the d e c i s i o n framework of an i n d i v i d u a l i n s e l e c t i n g a mode of t r a v e l . T h i r d stage s t u d i e s d i s a g g r e g a t e t r a v e l phenomena to i n d i v i d u a l me-asurements and mathematical models are c o n s t r u c t e d to r e p l i c a t e the beh a v i o r processes of the i n d i v i d u a l . However, two e x t e n s i o n s of the t h i r d stage are- needed to begin to f u l l y a p p r e c i a t e the r a m i f i c a t i o n s of t r a n s p o r t a t i o n p o l i c y . These are a nalyses of the interdependence of the socioeconomic s t r u c -t u r e and system a t t r i b u t e s , and the e x t e n s i o n s of b e h a v i o r a l o b s e r v a t i o n s to i n c l u d e s u b j e c t i v e p r e f e r e n c e s . Research on the mode s p l i t has emphasized the i n f l u e n -ces on mode c h o i c e through the use of some type of mathematical model. The f i r s t stage s t u d i e s c o n c e n t r a t e d almost e n t i r e l y on models of urban s t r u c t u r a l i n f l u e n c e s a t the g l o b a l l e v e l o f a n a l y s i s . The second stage s t u d i e s emphasized models of t r a n s -p o r t a t i o n system i n f l u e n c e s . These two s t a g e s , mostly c a r r i e d out i n c o n j u n c t i o n w i t h the major u r b a n - r e g i o n t r a n s p o r t a t i o n s t u d i e s , form the c o n c e p t u a l bases of determinants of mode c h o i c e . A b r i e f review of the socioeconomic s t r u c t u r a l c harac-t e r i s t i c s and those of the t r a n s p o r t a t i o n system which have been found t o i n f l u e n c e mode c h o i c e i s g i v e n below as a p r e l u d e to an a n a l y s i s of the interdependence o f these i n f l u e n c e s . INFLUENCE OF URBAN SOCIOECONOMIC STRUCTURE  ON MODE SPLIT E a r l y attempts to es t i m a t e mode s p l i t r e l i e d l a r g e l y on the v a r i a t i o n i n urban s t r u c t u r a l c h a r a c t e r i s t i c s as they r e l a t e d t o percentage of t r a n s i t use. M i t c h e l l and Rapkin"*" i n the e a r l y 1950's formulated the concept t h a t l a n d use a c t i v i t y 1 8 . was the c a u s a l f a c t o r i n urban t r a v e l . F u r t h e r work i n the 2 3 4 e a r l y region-wide t r a n s p o r t a t i o n s t u d i e s , ' ' e s t a b l i s h e d f i r m l y the l i n k between urban s t r u c t u r e and i n t e r a c t i o n by o b s e r v i n g e m p i r i c a l r e g u l a r i t i e s between urban a c t i v i t y and t r a f f i c f l o w s . S i n c e mode s p l i t was a simple d i v i s i o n of t o t a l person t r i p s the b a s i s f o r s t r u c t u r a l a s s o c i a t i o n with those who used t r a n s i t and those who used p r i v a t e modes seemed 5 obvious. Curran and Stegmaier found the p r o p o r t i o n of work g t r i p s by t r a n s i t i n c r e a s e d w i t h c i t y s i z e . Adams, i n 1959, d i s a g g r e g a t e d g l o b a l f a c t o r s to r e l a t e p o p u l a t i o n , l a b o u r f o r c e c h a r a c t e r i s t i c s and automobile ownership r a t e s to t r a n s i t use. 7 The Chicago Area T r a n s p o r t a t i o n Study, the f i r s t of the major u r b a n - r e g i o n s t u d i e s to i n c l u d e a s p e c i f i c s t r a t i -f i c a t i o n of t r i p s by mode, concluded t h a t mode s p l i t was r e l a -t e d to the unique a c t i v i t y of the C e n t r a l B u s i n e s s D i s t r i c t . The r e l a t i o n s h i p between mode s p l i t and the s t r u c t u r e of the 8 CBD i s supported elsewhere. A study by T a a f f e e t a l showed t h a t socioeconomic and modal d i f f e r e n c e s e x i s t e d between those who commuted to the C e n t r a l Business D i s t r i c t and those who commuted to p e r i p h e r a l job l o c a t i o n s . Recent s t u d i e s have tended to show t h a t the mode s p l i t of t r i p s to the CBD i s changing i n favour of automobile commuting i n a s s o c i a t i o n w i t h s t r u c t u r a l changes i n the CBD daytime p o p u l a t i o n . Evidence i n d i c a t e s t h a t w h i l e t o t a l CBD a c t i v i t y remains c o n s t a n t i n l a r g e c i t i e s t here has been an i n c r e a s e i n automobile commuting • 4- -4- 4." 9,10,11 and a decrease i n t r a n s i t commuting. S e v e r a l socioeconomic f a c t o r s are a s s o c i a t e d w i t h mode c h o i c e . C l e a r a s s o c i a t i o n s have been found between the number of t r a n s i t r i d e r s generated by a t r a f f i c zone and f a c t o r s such as c a r ownership, income, f a m i l y composition and s o c i a l s t a t u s . Car Ownership Some i n v e s t i g a t o r s b e l i e v e t h a t c a r ownership and 12 mode c h o i c e are synonomous. L a n s i n g and Hendricks document t h a t 9 2 p e r c e n t of commuters i n the U n i t e d S t a t e s use an auto-mobile i f t h e r e are as many automobiles as a d u l t s i n the f a m i l y . However, as c a r ownership per f a m i l y i n c r e a s e s the r e d u c t i v e e f f e c t on t r a n s i t r i d e r s h i p d e c r e a s e s . I t appears t h a t there i s a minimum l e v e l of t r a n s i t usage which i s t h e r e f o r e to a degree independent of c a r ownership. T h i s minimum i s r e f e r r e d to as " c a p t i v e " t r a n s i t r i d e r s , or those who have no o t h e r means of t r a v e l . Car ownership i s i n f a c t a proxy measurement of c a r a v a i l a b i l i t y f o r a s p e c i f i c t r i p . C l e a r l y i f a one c a r house-h o l d has more than one employed member the c o m p e t i t i o n f o r the ca r e n t e r s i n t o the mode c h o i c e d e c i s i o n . Some i n v e s t i g a t o r s have used an index of household t r i p g e n e r a t i o n ( r e l a t e d to income) d i v i d e d by the number of automobiles as an indepedent 13 14 i n f l u e n c e on mode c h o i c e r a t h e r than c a r ownership. ' 20. The use of c a r ownership (or a v a i l a b i l i t y ) as an independent v a r i a b l e f o r mode c h o i c e i s f r a u g h t with c o n c e p t u a l d i f f i c u l t i e s . There i s the problem of c a u s a l i t y ( i . e . does owning an automobile "cause" i t s use f o r the work t r i p , or does l a c k of a l t e r n a t i v e s e r v i c e "cause" one to purchase a c a r ) . There i s a l s o the problem of the i n t e r a c t i o n o f auto ownership w i t h income and t r a v e l c o s t v a r i a b l e s . Lave"^ p o i n t s out the two extremes; i f a f a m i l y owns a c a r f o r o n l y one reason, t r a n s p o r t a t i o n to work, and i f t o t a l c o s t (time and d o l l a r ) i s l e s s by auto than by t r a n s i t , auto ownership would p r e d i c t mode c h o i c e , but would not e x p l a i n i t because c a u s a l i t y i s s t i l l c onfused. I f , on the othe r hand, c a r s were t r e a t e d as p u r e l y s o c i a l goods which are purchased f o r a c t i v i t i e s other 1 than commuting to work, c a r ownership would be a f u n c t i o n of f a m i l y income. I f the former s i t u a t i o n p r e v a i l e d auto ownership as an environmental c o n s t r a i n t should not be i n c l u d e d i n a mode s p l i t a n a l y s i s s i n c e the c o s t and time f a c t o r s c o n s i d e r i t s e f f e c t ; i f the l a t t e r case p r e v a i l s i t i s a f u n c t i o n of income. For these reasons, c a r ownership, although used e x t e n s i v e l y , i s not a good e x p l a n a t o r y f a c t o r i n mode c h o i c e . An a s s o c i a t e d q u e s t i o n i s whether or not a c a r i s necessary a t work. Recent s t u d i e s have t r i e d t o assess t h i s . f a c t o r and the concensus i s t h a t i f a c a r i s a necessary p a r t of the work s i t u a t i o n no mode c h o i c e e x i s t s . However, the importance of t h i s f a c t o r i n p o t e n t i a l t r a n s i t use depends upon the frequency of car use, and whether or not a c t u a l use i s made of the car when i t i s r e p o r t e d as necessary f o r work. I t i s p o s s i b l e t h a t many respondents r e p o r t a need f o r the c a r a t work to j u s t i f y t a k i n g i t to work, whereas i t s use may be very i n f r e q u e n t or even n o n - e x i s t e n t . These people may be p o t e n t i a l t r a n s i t p atrons under d i f f e r e n t c o n d i t i o n s , s p e c i f i c a l l y i f t r a n s i t s e r v i c e improves d r a m a t i c a l l y . Income Income as an i n f l u e n c e on the mode s p l i t may a c t as an environmental c o n s t r a i n t , through c a r ownership f o r example, o r i t may a c t through time and c o s t on the system by i n f l u e n c i n g the r e l a t i v e weight g i v e n to these i n the mode c h o i c e d e c i s i o n . T r a n s p o r t a t i o n study f i n d i n g s , which t y p i c a l l y c o n s i d e r both " c a p t i v e " and " c h o i c e " r i d e r s have shown income to be an impor-J. .L . . ^ , . 16,17,18,19 _,. . ., t a n t c o n s t r a i n t on mode c h o i c e . I f a c a r i s a v a i l -a b l e f o r a s p e c i f i c t r i p , however, the e f f e c t of income i s d o u b t f u l . Recent s t u d i e s c o n t r o l l i n g the income c o n s t r a i n t by c o n s i d e r i n g o n l y those respondents w i t h a car a v a i l a b l e have shown t h a t f a m i l y income l e v e l s do not a c t d i r e c t l y i n mode 20 s p l i t models but onl y through system v a r i a b l e s . Warner con-s i d e r e d the income e f f e c t ( h o l d i n g car ownership constant) t o have two components. The f i r s t when automobile t r a v e l i s more expensive than t r a n s i t (thereby p o s t u l a t i n g t h a t h i g h e r incomes l e s s e n the e f f e c t of c o s t as a d e t e r r e n t to automobile c h o i c e ) ; and second when t r a n s i t i s more expensive (where lower incomes would favour c a r u s e ) . He found t h a t the income e f f e c t t r e a t e d 21 i n t h i s manner had l i t t l e e f f e c t on mode c h o i c e . Quarmby found the income e f f e c t i n s i g n i f i c a n t even though he found the mode c o s t d i f f e r e n c e s i g n i f i c a n t , i n f e r r i n g t h a t income had no e f f e c t beyond i t s e f f e c t as measured by c o s t of t r a v e l . Both Warner and Quarmby conclude t h a t once c a r ownership and l o c a t i o n of r e s i d e n c e i s de c i d e d upon, income has l i t t l e e f f e c t on mode c h o i c e . In summary the evidence shows t h a t i f both c a p t i v e and c h o i c e t r i p s are i n c l u d e d i n the a n a l y s i s , income i s an important environmental f a c t o r i n the c h o i c e of mode: w i t h those o f low income b e i n g c a p t i v e s and t h e r e f o r e l o c a t i o n a l f a c t o r s of home and work c a r r y i n g more weight i n the mode c h o i c e d e c i s i o n than s e r v i c e a t t r i b u t e s . On the o t h e r hand, where on l y c h o i c e t r i p s are c o n s i d e r e d , income as an e n v i r o n -mental f a c t o r may be unimportant. Family Composition Sex, age, f a m i l y s i z e have been shown to be assoc-i a t e d w i t h modal s p l i t i n v a r y i n g degrees. Women i n a l l age 22 groups are more l i k e l y t o take t r a n s i t than men. Hoel e t a l , 23 24 25 26 27 Warner, T a a f f e , Bock, L e a t h e r s , and Wilson have a l l found t r a n s i t use i n c r e a s e s w i t h the number of females i n the work f o r c e . Age s t r u c t u r e may be a f a c t o r a l s o . I n c r e a s e d t r a n s i t use i s a s s o c i a t e d w i t h age groups on both ends of the 23 . p o p u l a t i o n age d i s t r i b u t i o n . Bock found t h a t s i g n i f i c a n t l y fewer persons i n the 25-44 age group used p u b l i c t r a n s i t to work. Hoel e t a l found the h i g h e s t p r o p o r t i o n of t r a n s i t users i n the 35-65 age group. On the other hand, Warner found no i n f l u e n c e due to age. Family s i z e i s a d i r e c t determinant of mode c h o i c e through i t s e f f e c t on auto ownership and c o m p e t i t i o n f o r auto 2 8 use i n the f a m i l y . W i l s o n found f a m i l y s i z e to be a d e t e r -mining i n f l u e n c e . Family s i z e e f f e c t s i n Kain's model operated 29 through r e s i d e n t i a l space p r e f e r e n c e . Warner and Bock's household r e s t r i c t i o n f a c t o r s of the c o m p e t i t i v e e f f e c t s of f a m i l y s i z e and number of autos a v a i l a b l e has been mentioned. Oi and S h u l d i n e r " ^ concluded t h a t l a r g e r f a m i l i e s u t i l i z e each auto more i n t e n s i v e l y , but t h a t the i n c r e a s e d u t i l i z a t i o n of t r a n s i t a c c o r d i n g to f a m i l y s i z e i n c r e a s e s a t a f a s t e r r a t e than i n t e n s i t y of auto use. S o c i a l S t a t u s Although bus t r a n s i t i s commonly a s s o c i a t e d w i t h low p r e s t i g e , f a c t o r s measuring s o c i a l rank have not been c o n s i d e r e d major c o n t r i b u t i n g ones mainly because they a c t through measur-abl e • v a r i a b l e s (such as income). Some work has r e l a t e d occupa-31 t i o n to mode c h o i c e . Reeder was s p e c i f i c a l l y concerned w i t h the v a r i a t i o n of c e r t a i n socioeconomic groups w i t h t r a n s p o r t a -t i o n t i m e - c o s t e x p e n d i t u r e s . Although Reeder found s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e i n o c c u p a t i o n a l groups on the o v e r a l l time of t r a v e l (higher- s t a t u s occupations spend l e s s time t r a v e l l i n g ) , he found no r e l a t i o n s h i p between occu-p a t i o n and c o s t , nor between o c c u p a t i o n and mode of t r a v e l to work. Bock, on the oth e r hand, found o c c u p a t i o n to have an i n f l u e n c e on mode t h a t " i s t o some exte n t independent of c a r ownership." Oi and S h u l d i n e r ' s study made an e x t e n s i v e a n a l y s i s of o c c u p a t i o n and t r i p g e n e r a t i o n with the concomitant v a r i a b l e s of c ar ownership and household s i z e c o n t r o l l e d , and demonstrated t h a t o c c u p a t i o n o f household head a f f e c t s t r i p g e n e r a t i o n . No a n a l y s i s of mode s p l i t v a r i a t i o n however was done i n t h i s study. 3 2 K a i n has examined race and t r a n s p o r t a t i o n and re c o r d s t h a t negro commuters are more l i k e l y t o use t r a n s i t than w h i t e s . No s t u d i e s have c o n c e n t r a t e d on e d u c a t i o n a l determinants, except to the ex t e n t e d u c a t i o n a c t s through o t h e r v a r i a b l e s . INFLUENCE OF TRANSPORTATION SERVICE ON MODE SPLIT , The c o n s i d e r a t i o n of t r a n s p o r t a t i o n s e r v i c e as an i n f l u e n c e on mode s p l i t began wi t h the E r i e and Puget Sound 33 3 4 T r a n s p o r t a t i o n s t u d i e s . ' In these s t u d i e s i t was r e c o g -n i z e d t h a t t r a n s p o r t a t i o n s e r v i c e q u a l i t y i n . r e l a t i o n to oppor-t u n i t i e s would a f f e c t the mode s p l i t . Each zone was a s s i g n e d an " a c c e s s i b i l i t y index," which was a f u n c t i o n of a l l job o p p o r t u n i t i e s a v a i l a b l e and the t o t a l t r a v e l time f o r each mode. The r a t i o of a c c e s s i b i l i t y i n d i c e s became known as the a c c e s s i b i l i t y r a t i o and was a measure of r e l a t i v e s e r v i c e q u a l i t y a p p l i e d to each zone. Curves, s t r a t i f i e d by zon a l household c h a r a c t e r i s t i c s and r e l a t i n g a c c e s s i b i l i t y r a t i o s to p e r c e n t t r a n s i t from each zone, became the b a s i s o f mode s p l i t e s t i m a t i o n . Although s e r v i c e q u a l i t y i n the form of an a c c e s s i -b i l i t y index f o r each zone was used i n these s t u d i e s , system performance was abstracted, t o the zonal l e v e l and t h e r e f o r e d i d not t r u l y r e p r e s e n t the c h o i c e o f s e r v i c e f a c t o r s f a c i n g a t r a v e l l e r . The next stage i n the e v o l u t i o n of mode s p l i t techniques was to i n c l u d e a c t u a l s e r v i c e c h a r a c t e r i s t i c s as a determinant i n the c h o i c e d e c i s i o n . 3 5 3 6 3 7 H i l l and von Cube ' ' working w i t h 1956 o r i g i n d e s t i n a t i o n data of the M e t r o p o l i t a n Toronto P l a n n i n g Board were i n s t r u m e n t a l i n d e v e l o p i n g the i d e a t h a t system a t t r i -butes were c e n t r a l to the mode c h o i c e d e c i s i o n . The concept was t h a t the volume of people moving between o r i g i n and d e s t i n a -t i o n form a t r a v e l market, and the v a r i o u s modes are competing f o r a share o f t h i s market. Each w i l l be s u c c e s s f u l i n a c h i e v i n g a p o r t i o n of the market depending upon i t s c o m p e t i t i v e p o s i t i o n v i s - a - v i s the advantages and disadvantages i t o f f e r s as measured by the a t t r i b u t e s o f r e l a t i v e t r a v e l time, t r a v e l c o s t , and convenience. E x t e r n a l f a c t o r s such as economic s t a t u s (income) and t r i p purpose are market c h a r a c t e r i s t i c s which determine r e a c t i o n to the performance a t t r i b u t e s . In a p p l y i n g these i d e a s H i l l and von Cube c a l c u l a t e d r a t i o s of r e l a t i v e times, c o s t s , and convenience f o r each zonal i n t e r c h a n g e . A l l t r i p i n t e r c h a n g e s were s t r a t i f i e d a c c o r d i n g t o s e v e r a l income c a t e -g o r i e s and ag a i n s t r a t i f i e d by the r a t i o of t r a n s i t f a r e s to v e h i c l e o p e r a t i n g and p a r k i n g c o s t s . A t h i r d s t r a t i f i c a t i o n was made of s e r v i c e r a t i o s as measured by walking and w a i t i n g times by t r a n s i t d i v i d e d by p a r k i n g delay and wal k i n g time f o r auto d r i v e r s . A f a m i l y of curves d e r i v e d by r e g r e s s i o n a n a l y -s i s f o r each group of t r a v e l l e r s showed percentage t r a n s i t i n t e r c h a n g e a g a i n s t the t r a v e l time r a t i o between zones. T h i s meant t h a t a t r a v e l l e r i n f a c i n g a d e c i s i o n about h i s c h o i c e of mode c o n s i d e r s the r e l a t i v e m e r i t s o f the modes a v a i l a b l e to him i n making h i s journey, and chooses t h a t mode he per-c e i v e s to p r o v i d e the b e s t s e r v i c e w i t h i n h i s environmental c o n s t r a i n t s ( i n t h i s case h i s income). The b e h a v i o r a l b a s i s of t h i s concept was r e c o g n i z e d but no attempt was made by the dev e l o p e r s to r e l a t e t h i s to consumer c h o i c e t h e o r y . The b a s i c concepts and technique i n i t i a t e d by H i l l 3 8 39 and von Cube, were a p p l i e d to s e v e r a l urban a r e a s . ' T h e i r work was a l s o c l o s e l y p a r a l l e l e d by others who used some exten-40 41 s i o n s o f m o d i f i c a t i o n s of t h i s approach. ' The importance of these s t u d i e s were t h a t they documented the t r a n s p o r t a t i o n system v a r i a b l e s which i n f l u e n c e d mode s p l i t . O v e r a l l T r a v e l Time A l l t r a n s p o r t a t i o n p l a n n i n g s t u d i e s are based on the c e n t r a l importance of t r a v e l time as a f a c t o r i n both s p a t i a l d i s t r i b u t i o n of t r a v e l and the mode s p l i t . In a simple mode s p l i t model such as those used b e f o r e the mid f i f t i e s , a m i n i -mum time path a l g o r i t h m a s s i g n s t r i p s to the a l t e r n a t e modes by means of an e m p i r i c a l l y d e r i v e d d i v e r s i o n curve which d e t e r -mined what percentage of t r i p s would be " d i v e r t e d " t o t r a n s i t on the b a s i s of the r e l a t i v e t r a v e l times by t r a n s i t and auto-mobile. The importance of t r a v e l time i s f i r m l y r o o t e d i n trans p o r t a t i o n study procedures f o r two reasons. F i r s t , i t r e p r e -sents a v a l i d s i n g l e parameter of t r a v e l . Cost and d i s t a n c e parameters have been c o n s i d e r e d i n v a r i o u s s t u d i e s but t r a v e l time i s i n v a r i a b l y used as a s i n g u l a r i n f l u e n c e . Secondly, i t has been found i n v i r t u a l l y a l l subsequent s t u d i e s t o be an important i n f l u e n c e , p a r t i c u l a r l y a t the m i c r o - l e v e l . O v e r a l l t r a v e l time i s made up of walk times a t both ends of the t r i p , w a i t times, time spent i n the v e h i c l e , t r a n s f e r times i f by p u b l i c t r a n s i t , and time to park. Both a b s o l u t e and r e l a t i v e t r a v e l times have been used i n mode s p l i t r e s e a r c h , although the r e l a t i v e times v i a the mode used to the b e s t a l t e r n a t i v e i s fa v o u r e d . T h i s a r i s e s from the concept t h a t once the d e c i s i o n i s made to t r a v e l to a p a r t i c u l a r d e s t i n a t i o n , the mode c h o i c e d e c i s i o n i s based on the c o m p e t i t i v e advantage of the a t t r i b u t e s o f the modes 2 8 . a v a i l a b l e . A c o n t r o v e r s y e x i s t s about the proper measurement to r e p l i c a t e the c a l c u l u s of the d e c i s i o n maker: the r a t i o of t r a v e l times or a b s o l u t e d i f f e r e n c e s i n t r a v e l time. N e i t h e r seems completely adequate. R a t i o s are c o n s i d e r e d not s u f f i c i e n t l y i n t u i t i v e , i n t h a t one does not t h i n k i n terms of r a t i o s but i n terms of minutes saved (or l o s t ) and l a r g e d i f -f e r e n c e s i n o v e r a l l t r a v e l time c o u l d e x i s t f o r t r i p s with the same r a t i o . The r e v e r s e problem e x i s t s with the use of t r a v e l time d i f f e r e n c e s ; t h a t i s , a time d i f f e r e n c e of (say) 5 minutes i n a 40 minute t r i p would have a d i f f e r e n t p e r c e i v e d v a l u e than i n a 10 minute t r i p . O v e r a l l T r a v e l C o s t O v e r a l l t r a v e l c o s t i n c l u d e f a r e s f o r t r a n s i t and v e h i c l e o p e r a t i n g c o s t s , p a r k i n g c o s t s and/or t o l l s f o r auto-m o b i l e s . The same d i f f i c u l t i e s i n r e p l i c a t i n g t r a v e l l e r d e c i -s i o n c a l c u l u s i n c o s t r a t i o s of d i f f e r e n c e s a p p l i e s to r e l a t i v e c o s t as t o r e l a t i v e time. I f a l l o t h e r f a c t o r s are equal the cheaper mode should be the p r e f e r r e d one, and g i v e n t h a t the user has a p r o p e n s i t y to economize, the r e l e v a n t q u e s t i o n i s whether the c o s t s t i m u l u s i s p r o p o r t i o n a l to the r a t i o of d i f -f e r e n c e i n c o s t s . Most i n v e s t i g a t o r s opt f o r the use of c o s t d i f f e r e n c e s . Excess T r a v e l Time Excess t r a v e l time i s t h a t which occurs o u t s i d e the t r a n s i t v e h i c l e , walk, w a i t , t r a n s f e r and p a r k i n g time and walking time f o r automobile d r i v e r s . Excess times are usually-aggregated and t r e a t e d as a s e p a r a t e f a c t o r i n the mode s p l i t e q u a t i o n because these times appear more onerous to t r a v e l l e r s than the i n - v e h i c l e times. Where they have been t r e a t e d s p e c i -f i c a l l y they are u s u a l l y found t o weigh 2-3 times the v a l u e o f o v e r a l l t r a v e l time. Quarmby found excess times to be 2.5 to 42 43 3 times o v e r a l l t r a v e l times. P r a t t uses a f a c t o r of 2.5. No s t u d i e s have d i s a g g r e g a t e d excess time i n t o p o l i c y components, say the e f f e c t of CBD f r i n g e p a r k i n g , or a park and r i d e system which i n c o r p o r a t e s t r a n s f e r times f o r auto d r i v e r s a t the f r i n g e t e r m i n a l . Comfort and Convenience There i s i n t u i t i v e appeal t o the i d e a t h a t comfort f a c t o r s are major determinants of the c h o i c e of mode. A i r c o n d i t i o n e d buses, non-crowded v e h i c l e s , t r a n s i t s h e l t e r s are a l l f a c t o r s which the l i t e r a t u r e suggests may a t t r a c t more people t o t r a n s i t . U n f o r t u n a t e l y very l i t t l e r e s e a r c h has e x p l i c i t l y c o n c e n t r a t e d on these f a c t o r s i n mode c h o i c e . Nash 44 and H i l l have used f a c t o r a n a l y s i s to assess the importance of a t t r i b u t e s of an i d e a l t r a n s p o r t a t i o n system. They r e p o r t t h a t d e s t i n a t i o n r e l i a b i l i t y , convenience and comfort f a c t o r s rank f i r s t and second as d e s i r a b l e a t t r i b u t e s . The comfort and convenience f a c t o r i n c l u d e d such items as a v o i d i n g changing v e h i c l e , weather w h i l e t r a v e l l i n g , weather w h i l e w a i t i n g , 45 s h o r t e s t time, and a v o i d w a i t i n g more than 5 minutes. Bock 30 . found comfort ranked second of a l l f a c t o r s d e t e r m i n i n g mode c h o i c e . 46 A c k o f f attempted to assess comfort f a c t o r s by means of a 7 p o i n t L i k e r t s c a l e . He found t h a t h i s s u b j e c t s c o u l d not d i s c r i m i n a t e between changes i n the sub-components of comfort but c o u l d s c a l e the r e l a t i v e l e v e l of o v e r a l l com-f o r t . For work purpose t r i p s h i s s u b j e c t ' s s e n s i t i v i t y to comfort was o n l y exceeded by t h e i r s e n s i t i v i t y to t r a v e l time. For " other" purpose t r i p s comfort ranked the h i g h e s t i n s e n s i -t i v i t y . P a r k i n g F a c t o r s High p a r k i n g c o s t s are among the most important reasons some people use t r a n s i t . S e n s i t i v i t y t e s t s have shown t h a t changing p a r k i n g c o s t s , p a r k i n g d e l a y , and w a l k i n g times i n the CBD have a g r e a t e r e f f e c t on the modal s p l i t than changing l i n e 47 48 h a u l s e r v i c e l e v e l s . Quarmby s i m u l a t e d p a r k i n g c o s t changes i n h i s model and found a 43 p e r c e n t d i v e r s i o n to p u b l i c t r a n s -p o r t with a Is surcharge per day, and a 59 p e r c e n t d i v e r s i o n o w i t h a surcharge of 3s per day. I f walking times from p a r k i n g l o t to workplace were i n c r e a s e d by 5 minutes a 39 p e r c e n t d i v e r -s i o n would occur. The M e t r o p o l i t a n Toronto P l a n n i n g Board t e s t e d the e f f e c t s of d o u b l i n g the c o s t of p a r k i n g i n downtown Toronto and e s t i m a t e d t h a t 33,730 persons might be d i v e r t e d from autos to t r a n s i t d u r i n g the 7-9 am peak. The subway r i d e r s h i p alone would i n c r e a s e by 26.5 p e r c e n t on the Yonge-U n i v e r s i t y l i n e and 28,4 p e r c e n t on the B l o o r - D a n f o r t h l i n e . Where p a r k i n g has been s u p p l i e d a t t r a n s f e r p o i n t s on r a i l commuter and subway l i n e s the number of commuters, as measured by the number of parkers who p r e v i o u s l y drove a l l the way down-49 50 town, a l s o shows some dramatic i n c r e a s e s . ' A l l i n d i c a t i o n s p o i n t t o p a r k i n g p o l i c y as an e x c e l -l e n t instrument t o a d j u s t mode s p l i t . P a r k i n g r e s t r i c t i o n s c o u l d be used to i n f l u e n c e demand p r o v i d i n g a m u n i c i p a l p a r k i n g a u t h o r i t y i s e s t a b l i s h e d t o r e t a i n c o n t r o l of the supply o f p a r k i n g spaces, t h e i r l o c a t i o n , and charges. The urban t r a n s p o r t a t i o n s t u d i e s and the a n c i l l a r y r e s e a r c h c a r r i e d out i n c o n j u n c t i o n with these s t u d i e s were e x t r e m e l y ' v a l u a b l e i n d e l i n e a t i n g those i n f l u e n c e s which c o u l d be u s e f u l to p r e d i c t mode s p l i t . However , the process has one very s e r i o u s c o n c e p t u a l problem; t h a t of data a g g r e g a t i o n . The Problem of A g g r e g a t i o n Comprehensive urban t r a n s p o r t a t i o n p l a n n i n g s t u d i e s use m a c r o - a n a l y s i s . There was o r i g i n a l l y a good reason f o r t h i s ; d e c i s i o n s were needed about t o t a l t r a n s p o r t a t i o n systems to meet immediate post-war backlogs i n freeway c o n s t r u c t i o n . E m p i r i c a l g e n e r a l i z a t i o n s of human beh a v i o r were observed and aggregated to g e o g r a p h i c a l zones which were designed to be homogeneous i n terms of demographic c h a r a c t e r i s t i c s . In many cases " t r a f f i c zones" were c o i n c i d e n t w i t h census t r a c t s . The presumption was t h a t w i t h i n zone c h a r a c t e r i s t i c s had l e s s v a r i a -t i o n than between zone c h a r a c t e r i s t i c s . T h i s has the i m p l i e d assumptions t h a t the zone sample mean i s r e p r e s e n t a t i v e of the households i n a zone, t h a t the zone sample mean i s a r e l i a b l e e s t i m a t e of the p o p u l a t i o n mean, and t h a t zonal sample data are homogeneous with r e s p e c t to the c h a r a c t e r i s t i c s b e i n g s t u d i e d . These assumptions are now h i g h l y s u s p e c t . Consequently, as 51 . Stopher p o i n t s out, the process o f t r a n s p o r t a t i o n p l a n n i n g i s r e a l l y d e f i n e d i n terms of socioeconomic c h a r a c t e r i s t i c s of the p o p u l a t i o n r a t h e r than i n terms of t r a n s p o r t a t i o n s e r v i c e s . F o r e c a s t i n g mode c h o i c e i s based on the assumption t h a t people w i l l change t h e i r socioeconomic c l a s s , and t h a t t h e i r t r a v e l h a b i t s w i l l change t o conform w i t h the c l a s s they have moved i n t o . T h i s assumes va l u e s t r u c t u r e s are c o n s t a n t w i t h i n a s o c i a l c l a s s , a h i g h l y d e b a t a b l e assumption. The f i r s t s t u d i e s on a n a l y z i n g mode s p l i t a t the zona l l e v e l showed l i t t l e e f f e c t from system a t t r i b u t e s . T h i s may have been the r e s u l t o f l a r g e v a r i a t i o n on measures of t r a n s p o r t a t i o n system c h a r a c t e r i s t i c s w i t h i n the zones r e l a t i v e 52* 53 to those between zones. Hutchinson has found, f o r example, t h a t i n a t e s t of one area of 247 zones the v a r i a n c e of t r i p making w i t h i n zones was almost 80 p e r c e n t w h i l e the between zone *McCarthy has found t h a t zone sampling d i s t r i b u t i o n s are skewed, and t h a t the mean i s t h e r e f o r e not r e p r e s e n t a t i v e of the c e n t r a l tendency of the zon a l data (see Ref. 52). v a r i a n c e i n t r i p making was only 20 p e r c e n t of the t o t a l . I f i n d i v i d u a l s w i t h i n a zone, w h i l e having s i m i l a r socioeconomic c h a r a c t e r i s t i c s , have l a r g e v a r i a t i o n i n t r a v e l h a b i t s , or p r o p e n s i t i e s f o r t r a v e l , i t i s u n l i k e l y t h a t p r o j e c t s based on the r e l a t i o n s h i p s between these c h a r a c t e r i s t i c s and mode s p l i t w i l l r e f l e c t the va l u e s of i n d i v i d u a l t r a v e l l e r s . T h i s may account i n p a r t f o r the d i f f i c u l t y i n r e p l i c a t i n g a c t u a l t r i p s to the CBD where systems c h a r a c t e r i s t i c s have a r e c o g -n i z e d i n f l u e n c e . I t may a l s o account f o r the l a c k of u n i -v e r s a l i t y of f o r m u l a t i o n s based on geographic a g g r e g a t i o n . I t appears l o g i c a l l y r e a s o n a b l e t h a t v a r i a t i o n s i n the form and s t r u c t u r e of d i f f e r e n t urban r e g i o n s r e l a t i v e to the t r a n s p o r -t a t i o n s e r v i c e s would mean t h a t r e l a t i o n s h i p s between s t r u c t u r e and t r a n s p o r t a t i o n s e r v i c e i n one area would not be the same as i n another a r e a . T h i s seems to be r e f l e c t e d i n the many d i f f e r e n t determinants used i n the models. 54 Lowry has a g e n e r a l c r i t i c i s m of the aggregated approach t o urban a n a l y s i s ; the u n i v e r s a l s u b s t i t u t i o n of e m p i r i c a l l y d e r i v e d g e n e r a l i z a t i o n s f o r theo r y . T h i s c r i t i c i s m a p p l i e s e q u a l l y to t r a n s p o r t a t i o n p l a n n i n g . V a r i a b l e s are i n c l u d e d by i n t r o s p e c t i o n and by a knowledge of what other s t u d i e s have found s i g n i f i c a n t . The purpose of the process i s to make the model work. T h i s has meant t h a t mode s p l i t models have v i r t u a l l y no g e n e r a l i t y . A second g e n e r a l c r i t i c i s m of ag g r e g a t i o n i s t h a t the a n a l y s i s may not l e n d i t s e l f to r a t i o n a l r e s o u r c e a l l o c a t i o n . The impact o f t r a n s p o r t a t i o n plans f a l l s 3 4 . on i n d i v i d u a l s and s o c i a l and i n s t i t u t i o n a l u n i t s and must be 55 e v a l u a t e d i n terms of t h e i r w e l f a r e . E v a l u a t i n g t r a n s p o r -t a t i o n p l a n s which have g e o g r a p h i c a l a g g r e g a t i o n as the b a s i c a n a l y s i s u n i t may c r e a t e a m i s a l l o c a t i o n of r e s o u r c e s to the degree t h a t v a l u e s of system a t t r i b u t e s vary w i t h i n the zone. The i m p l i c i t assumption i n a g g r e g a t i o n i s t h a t z o n a l averages are r e p r e s e n t a t i v e o f the t r a v e l b e h a v i o r o f i n d i v i -d u a l s . That t h i s i s b e l i e v e d so has been termed the e c o l o g i c a l f a l l a c y and has r e s u l t e d i n aggregate v a r i a b l e s b e i n g so s t r o n g 5 6 as to c l o u d the r e a l b e h a v i o r a l a s s o c i a t i o n s . The r e c o g n i -t i o n of t h i s b a s i c f a l l a c y has l e d to b e h a v i o r a n a l y s i s based on s t a t i s t i c a l l y d i s a g g r e g a t e d d a t a . T h i s a l l o w s both a more r e l i a b l e b e h a v i o r model as w e l l as the a s s o c i a t i o n of mode c h o i c e with the t h e o r e t i c a l concept of i n d i v i d u a l consumer c h o i c e t h e o r y . BEHAVIOR MODELS Warner's study, p u b l i s h e d i n 1962, i s important f o r the development of mode c h o i c e theory f o r two reasons: he observed i n d i v i d u a l b e h a v i o r ; and.he i n t r o d u c e d p r o b a b i l i t y theory i n t o mode s p l i t a n a l y s i s . Working w i t h data c o l l e c t e d by the Cook County Highway Department, Warner was concerned w i t h the i n f l u e n c e on an i n d i v i d u a l consumer's p r o b a b i l i t y c h o i c e e x e r t e d by t h r e e economic v a r i a b l e s ; t r i p time and t r i p c o s t s by the d i f f e r e n t modes, and the income of the t r i p t a k e r . His r e s e a r c h space i n c l u d e d 6 s e t s of b i n a r y c h o i c e ; (1) t h a t between automobile and c i t y mass t r a n s i t , (2) automobile and t r a i n , and (3) c i t y mass t r a n s i t and t r a i n f o r each of work and non-work purpose. Warner addresses h i s study to the ques-t i o n : g i v e n t h a t c h o i c e of mode i s a b i n a r y c h o i c e ( i . e . b e t -ween only two a l t e r n a t i v e s ) what are the odds of an i n d i v i d u a l choosing mode (say automobile) g i v e n t h a t h i s c h o i c e i s depen-dent upon h i s p e r c e i v e d r e l a t i v e combination of time and c o s t a t t r i b u t e s of the modes a v a i l a b l e , and upon h i s household income. His a n a l y s i s r e l a t e s the p r o b a b i l i t y d e n s i t y of sample responses to the economic demand f u n c t i o n . The income v a r i a b l e i n the demand e q u a t i o n i s t h a t which a f f e c t s mode c h o i c e s e p a r a t e l y from the c a r ownership f a c t o r , and en t e r s the f u n c t i o n as a r e l a t i v e t r a v e l c o s t / income index. A c a r a v a i l a b i l i t y v a r i a b l e was a l s o i n c l u d e d which was a proxy made up of household income, number of a d u l t s i n the household and number of c a r s . That i s , t h e l e v e l of income c r e a t e s the l e v e l of demand f o r t r a v e l , w h i l e an a d u l t / car r a t i o d e f i n e s the supply of auto r e s o u r c e s f o r t r a v e l . Theory of A b s t r a c t Modes 57 58 L a n c a s t e r , Quandt and Baumol were i n s t r u m e n t a l i n changing the course of mode c h o i c e r e s e a r c h i n 1966. L a n c a s t e r 1 paper i n t h a t year argued t h a t i t was the i n t r i n s i c p r o p e r t i e s of goods which were the o b j e c t of u t i l i t y , not the goods them-s e l v e s . T h i s was a break w i t h t r a d i t i o n a l u t i l i t y theory which t r e a t e d the goods i n combination as the o b j e c t of u t i l i t y . L a n c a s t e r argued t h a t a good, per se,. does not g i v e u t i l i t y but i t possesses c h a r a c t e r i s t i c s and i t i s these c h a r a c t e r i s t i c s which g i v e consumer s a t i s f a c t i o n . F u r t h e r , he added, "a good w i l l possesses more than one c h a r a c t e r i s t i c , and many charac-t e r i s t i c s w i l l be shared by more than one good." Moreover, "goods i n combination may possess c h a r a c t e r i s t i c s d i f f e r e n t from those p e r t a i n i n g t o the goods s e p a r a t e l y . " L a n c a s t e r ' s t h e s i s was based p a r t l y on Quandt's p r e v i o u s work and the l a t -t e r with Baumol, a p p l i e d these ideas to the. mode s p l i t problem. In the above quotes i f we read "mode" f o r "good" the theory of a b s t r a c t modes becomes c l e a r . Quandt and Baumol o u t l i n e s e v e r a l aspects of t h e i r theory of a b s t r a c t modes. D e f i n i n g a mode as a bundle of a t t r i b u t e s r a t h e r than the t r a d i t i o n a l i n s t i t u t i o n a l i z e d d e f i n i -t i o n a llows the p l a n n e r to assess the r e s u l t s of a r a d i c a l l y d i f f e r e n t mode by s i m u l a t i n g the new mode's c h a r a c t e r i s t i c s i n the model. Any number of a b s t r a c t mode types may be s t u d i e d by s i m u l a t i o n w h i l e having no r e a l w o r l d c o u n t e r p a r t . The theory presupposes t h a t i n d i v i d u a l s are c h a r a c t e r i z e d by modal neu-t r a l i t y , o r i n o t h e r words choose a mode p u r e l y on the b a s i s of i t s i n t r i n s i c a t t r i b u t e s and not on the b a s i s of what i t i s c a l l e d . The authors r e c o g n i z e d the tenuousness of s t r i c t modal n e u t r a l i t y ( t h e i r example i s an a v e r s i o n to f l y i n g by some p e o p l e ) , but a s i d e from those i n t r i n s i c q u a l i t i e s which may be i d e n t i f i e d with an i n s t i t u t i o n a l i z e d mode and may not be 3 7 . o b j e c t i v e l y measured, (such as p r e s t i g e of d r i v i n g your own car) the theory has g r e a t r e l e v a n c e to the study of new, t e c h n o l o -g i c a l l y r a d i c a l modes. T h e i r model i n a l o g l i n e a r form was t e s t e d by r e g r e s s i o n a n a l y s i s on i n t e r - c i t y t r i p s u s i n g v a r i -ables r e l a t i n g to the p o p u l a t i o n s of the modal p a i r s , median incomes, l e a s t t r a v e l time and c o s t , r e l a t i v e t r a v e l time and c o s t , and a b s o l u t e and r e l a t i v e d e p a r t u r e f r e q u e n c i e s . 59 Quandt i n a l a t e r paper d e f i n e s an a b s t r a c t mode model as t h a t which uses a g e n e r a l i z e d c o s t o r d i s u t i l i t y f u n c t i o n . . Y o u n g ^ demonstrates t h a t not o n l y i s the concept of g e n e r a l i z e d p r i c e i n the demand f u n c t i o n i n t u i t i v e l y sound, but a l s o t h e o r e t i c a l l y r i g o r o u s . Young shows t h a t an i n d i v i d u a l i n maximizing u t i l i t y can be made s u b j e c t to modal c o n s t r a i n t s s i m i l a r to the t r a d i t i o n a l income c o n s t r a i n t and by t h i s means demonstrates t h a t the demand f u n c t i o n s f o r i n d i v i d u a l s can be expressed i n terms of g e n e r a l i z e d p r i c e s which i n c l u d e both non-monetary as w e l l as monetary c h a r a c t e r i s t i c s of the modes i n q u e s t i o n . Young's argument appears simply to c o n s i d e r i n s t i t u t i o n a l i z e d modes as an environmental c o n s t r a i n t , as i s income, and develops demand f u n c t i o n s on mode c h a r a c t e r i s t i c s . U t i l i t y Theory and Mode Choice The a p p l i c a t i o n of the u t i l i t a r i a n concept, t h a t an i n d i v i d u a l t r a v e l l e r w i l l seek t o maximize s a t i s f a c t i o n s (or minimize d i s s a t i s f a c t i o n s ) , p re-dates the development of the 3 8 . concept of a b s t r a c t modes and g e n e r a l i z e d p r i c e s , although these l a t t e r developments were to g i v e u t i l i t y a n a l y s i s g r e a t e r t h e o r e t i c a l weight i n subsequent work. Warner, f o r example, makes i m p l i c i t r e f e r e n c e to the u t i l i t y h y p o t h e s i s . He says, "the t h e o r e t i c a l o b j e c t s of c h o i c e c o n s t i t u t e d i f f e r e n t c o l -l e c t i o n s of t r a n s p o r t a t i o n services."^"'" However, the p a r a -meters of h i s c h o i c e f u n c t i o n s ( p r o b a b i l i t y f u n c t i o n s ) are d e s c r i b e d i n e l a s t i c i t y terms where the r e s u l t a n t parameter est i m a t e s of " e l a s t i c i t y of c h o i c e " are i d e n t i c a l w i t h demand e l a s t i c i t i e s . 6 2 A c k o f f appears to have been the f i r s t to f o r m u l a t e an e x p l i c i t u t i l i t y model f o r mode c h o i c e . The model was based on the h y p o t h e s i s t h a t an i n d i v i d u a l would change from h i s u s u a l mode'to the b e s t a l t e r n a t i v e when the p e r c e i v e d d i f f e r e n c e s between the c h a r a c t e r i s t i c s of the modes became g r e a t enough. Using the c h a r a c t e r i s t i c s of t r a v e l time, t r a v e l c o s t , comfort and convenience he reasoned t h a t when p e r c e i v e d d i f f e r e n c e s i n any one mode c h a r a c t e r i s t i c reached a c e r t a i n l e v e l i t would cause c e r t a i n i n d i v i d u a l s to make a d e c i s i o n to change mode. The model was i n t e n ded to aggregate i n d i v i d u a l s on the b a s i s of t h e i r s e n s i t i v i t y to changes i n mode c h a r a c t e r i s t i c s . The study was not p u b l i s h e d however and the data d e s t r o y e d . 6 3 Quarmby was i n s t r u m e n t a l i n r e l a t i n g u t i l i t y theory to a s u c c e s s f u l mode s p l i t model. Quarmby c o n c e i v e d of t r a v e l "dimensions" ( t r a v e l time, w a l k i n g time, c o s t etc.) each of which g i v e s r i s e to some d i s u t i l i t y . The t r a v e l l e r w i l l choose t h a t mode which g i v e s him minimum d i s . u t i l i t y . I f some change occurs i n one or more "dimension" c a u s i n g an a l t e r n a t i v e mode to assume a lower v a l u e f o r d i s u t i l i t y , i t was p o s t u l a t e d t h a t an i n d i v i d u a l would change to the a l t e r n a t i v e mode. The r e l a -t i v e c o n t r i b u t i o n to the d i s u t i l i t y of each dimension are the e s t i m a t i n g parameters i n the e q u a t i o n . Assumptions of the model were t h a t the d i s u t i l i t y f u n c t i o n i s l i n e a r and a d d i t i v e . Reducing mode c h o i c e to a b i n a r y c h o i c e and e x p r e s s i n g d i s u t i l -i t y as a r e l a t i v e measure ( i . e . d i s u t i l i t y mode 1 r e l a t i v e to t h a t f o r mode 2) Quarmby develops a g e n e r a l r e l a t i v e d i s u t i l -i t y f u n c t i o n where the v a r i a b l e s are measured i n terms of d i f -f e r e n c e s . The model i s a d i s c r i m i n a t i o n - c l a s s i f i c a t i o n type where the d i s c r i m i n a t i o n f u n c t i o n i s the s t a t i s t i c a l a g g r e g a t i o of i n d i v i d u a l u t i l i t y f u n c t i o n s . S e v e r a l approaches t o t h i s b a s i c f o r m u l a t i o n have 64 f o l l o w e d . Quandt's u t i l i t y model of i n t e r - c i t y t r a v e l xs p r o b a b i l i s t i c with a n o n - l i n e a r u t i l i t y f u n c t i o n . P r a t t ' s * ^ t h e o r e t i c a l approach i s based on the f a c t t h a t the p r o b a b i l i t y of u s i n g the b e s t mode, f o r those with a f r e e c h o i c e , f o l l o w s 6 6 the normal p r o b a b i l i t y d e n s i t y f u n c t i o n . M c G i l l i v r a y uses a d i s c r i m i n a t i o n - c l a s s i f i c a t i o n model s i m i l a r to Quarmby but i n c l u d i n g budget c o n s t r a i n t , r e s i d e n t i a l space and l e i s u r e time, and w i t h s e r v i c e l e v e l s d e s c r i b e d by r a t i o s . 40. A t t i t u d e s i n the Mode Choice D e c i s i o n Some work has been c a r r i e d out to attempt t o assess the e x t e n t o f the i n f l u e n c e of a t t i t u d e s i n the mode c h o i c e d e c i s i o n and the r e l e v a n c e of a t t i t u d e s t u d i e s f o r p l a n n i n g of mode b a l a n c e . These have not as y e t formed any c o n s i s t e n t p a t t e r n . 6 7 A c k o f f used a type of a t t i t u d e survey to assess s c a l e d responses to the d i f f e r e n c e needed i n modal c h a r a c t e r i s -t i c to cause the respondent to change from h i s u s u a l mode t o the b e s t a l t e r n a t i v e . S e n s i t i v e n e s s o f each respondent to changes i n c h a r a c t e r i s t i c s were compared to the mean of the d i s t r i b u t i o n of a l l respondents f o r t h a t c h a r a c t e r i s t i c a l l o w i n g i n d i v i d u a l s t o be aggregated by t h e i r s e n s i t i v e n e s s to changes i n modal c h a r a c t e r i s t i c s r e l a t i v e to the s e n s i t i v e n e s s of the t y p i c a l (mean) i n d i v i d u a l . Nash and H i l l ^ used f a c t o r a n a l y s i s to determine the components on which respondents reduced an o r i g i n a l l i s t of s e v e r a l v a r i a b l e s to an i d e a l t r a n s p o r t a t i o n system. The authors found many n o n - q u a n t i f i a b l e and p s y c h o l o -g i c a l a t t r i b u t e s d e s i r e d i n an i d e a l system. Recent u n p u b l i s h e d s t u d i e s are now underway u s i n g a t t i t u d e surveys to v a l i d a t e hypotheses r e l a t i n g to the s u b j e c t i v e assessment of modal a t t r i b u t e s . ^ ' ^ P e r c e i v e d v s A c t u a l V a l u e s o f Time and C o s t  i n Mode C h o i c e M o d e l s M e a s u r e s o f s y s t e m a t t r i b u t e s u s e d h a v e b e e n e n g i -n e e r i n g m e a s u r e s . T i m e v a l u e s a r e e s t i m a t e d by s c h e d u l e s , s p e e d l i m i t s , t r i a l r u n s o r s o m e t i m e s b y a d i s t a n c e p r o x y . V e h i c l e o p e r a t i n g c o s t s a r e i n v a r i a b l y b a s e d o n an a v e r a g e p e r m i l e v a l u e a n d p a r k i n g c o s t s a r e i m p u t e d c o s t s . H o w e v e r , r e c e n t s t u d i e s a r e b a s e d o n r e p o r t e d t i m e s , a n d i f p o s s i b l e r e p o r t e d c o s t s o n t h e a s s u m p t i o n t h a t i t i s t h e s u b j e c t i v e v a l u e s o f t h e s e a t t r i b u t e s u p o n w h i c h t h e mode c h o i c e d e c i s i o n i s b a s e d . W a r n e r f o r e x a m p l e u s e s s u b j e c t i v e r e s p o n s e s . T h i s i n t u r n c r e a t e s a f u r t h e r p l a n n i n g p r o b l e m ; t h e e v a l u a t i o n o f p r o j e c t s b a s e d on e n g i n e e r i n g c o s t s a g a i n s t a demand m e a s u r e d b y s u b j e c -t i v e r e s p o n s e s . S e v e r a l o f t h e s t u d i e s h a v e a t t e m p t e d t o o v e r -come t h i s by r e l a t i n g s u b j e c t i v e v a l u e s t o o b j e c t i v e l y m e a s u r e d v a l u e s . Quarmby r e a s o n e d t h a t p e o p l e ' s p e r c e p t i o n o f t i m e m i g h t be r e l a t e d t o s u c h f a c t o r s as t r i p l e n g t h a n d r e l a t i v e c o m f o r t . He t h e r e f o r e a n a l y s e d by l i n e a r r e g r e s s i o n a c t u a l t e r m i n a l w a l k i n g t i m e s a g a i n s t r e p o r t e d t i m e s a n d f o u n d " e x t r e -m e l y " g o o d c o r r e l a t i o n s . He a l s o f o u n d " r e m a r k a b l e " a g r e e m e n t b e t w e e n p e r c e p t i o n o f o v e r a l l s p e e d a nd t i m e o f c a r t r a v e l b y c a r a n d b u s u s e r s , b u t t h a t c a r u s e r s ' p e r c e p t i o n o f bus t r a v e l t i m e s i s a b o u t 20 p e r c e n t s l o w e r t h a n t h a t o f b u s u s e r s . C a r u s e r s do n o t p e r c e i v e w a l k i n g a n d w a i t i n g t i m e s as a c c u r a t e l y as b u s u s e r s . T h e r e i s a l s o a s i g n i f i c a n t d i f f e r e n c e i n p e r c e i v e d in-bus t r a v e l times between car users and bus u s e r s . Bock a l s o found h i g h c o r r e l a t i o n betw.een r e p o r t e d and computed times i n Chicago. While t h e r e appears some correspondence between " o b j e c t i v e " measures of time and p e r c e i v e d time, a d i f f e r e n t c o n c l u s i o n on c o s t p e r c e p t i o n i s reached. Based on two 7 1 n a t i o n a l surveys ( 1 9 6 3 and 1 9 6 5 ) L a n s i n g concluded t h a t "people are w e l l aware of c o s t s which must be p a i d i n cash" such as p a r k i n g fees and f a r e s , but most people have not made an estimate of v e h i c l e c o s t s and those who made esti m a t e s of f u e l c o s t s were "unreasonably h i g h " r e l a t e d t o a c t u a l " e n g i -n e e r i n g " c o s t s . NEEDS OF A NEW APPROACH Mode s p l i t r e s e a r c h has shown an e v o l u t i o n from sim-p l i f i e d global.models t o h i g h l y r e f i n e d t h e o r e t i c a l models based on i n d i v i d u a l b e h a v i o r a l a s s o c i a t i o n s . These new models are p o t e n t i a l l y s u c c e s s f u l i n p r e d i c t i n g mode c h o i c e b e h a v i o r i f s u f f i c i e n t data i s c o l l e c t e d . However new models must be i n c o r p o r a t e d i n t o a p o l i c y and d e c i s i o n framework f o r p l a n n i n g , and t h i s i n v o l v e s some p o s s i b l e r e s t r u c t u r i n g of the models. The models must be formulated so they respond to p u b l i c p o l i c y and they must be s t r a t i f i e d by the groups a f f e c t e d by p o l i c y . Some problems with regard to t h i s are o u t l i n e d below. 4 3 . The Problem o f P o l i c y Content Mode mode c h o i c e r e s e a r c h has l i t t l e p o l i c y c o n t e n t . The t r a n s p o r t a t i o n s t u d i e s viewed mode s p l i t as a mechanical a l g o r i t h m , which had r e l e v a n c e f o r p o l i c y only t o the e x t e n t t h a t the f i n a l p r o d u c t was an e s t i m a t i o n of the volumes on the system. The be h a v i o r models are d e f i n e d by v a r i a b l e s which can t h e o r e t i c a l l y be i n f l u e n c e d by p o l i c y d e c i s i o n s on t r a v e l time and c o s t . Two models (Quarmby's and M c G i l l i v r a y ' s ) have been used to estimate the change i n mode s p l i t w i t h changes i n time and c o s t v a l u e s . M c G i l l v r a y compares the two s t u d i e s and f i n d s t h a t e f f e c t s from the two models are of the same o r d e r of magnitude. He concludes t h a t the e f f e c t o f c o s t changes i s never g r e a t e r than the e f f e c t o f changing t r a v e l time. These r e s u l t s are h y p o t h e t i c a l , based on s i m u l a t e d changes and ig n o r e system e f f e c t s due to decreases i n c o n g e s t i o n w i t h i n c r e a s e d t r a n s i t r i d e r s h i p . Assuming the approach used i n these models i s a v a l i d one i t i s necessary to i d e n t i f y the f u n c t i o n a l system and to determine the r e l a t i o n s h i p s between the system and the s o c i o -economic environment, and i n the f i n a l s t a g e , between the system and urban s p a t i a l form. Wingo d e s c r i b e s the "new p o l i c y frame-work" i n terms of new d e c i s i o n c r i t e r i a which i n c o r p o r a t e the " i n t e r r e l a t e d n e s s of p u b l i c and p r i v a t e d e c i s i o n s and...the 72 c r i t i c a l l i n k a g e s of the urban community." Furthermore, c l i e n t group v a l u e systems must be i n c o r p o r a t e d i n t o new d e c i s i o n c r i t e r i a . B e h a v i o r a l r e l a t e d models, p a r t i c u l a r l y the a b s t r a c t mode concept, a l l o w the e s t i m a t i o n o f b e h a v i o r a l e f f e c t s on the system. However, these models are c o n s t r a i n e d i n two ways; the l a c k of b e h a v i o r a l s t u d i e s f o r a l l segments of the urban p o p u l a t i o n as w e l l as f o r a wide r a n g i n g s e t of l a n d u s e - t r a n s p o r t a t i o n system c o n d i t i o n s ; and the changes i n the val u e systems of c l i e n t groups. While the t r a n s p o r t a t i o n s t u d i e s assume c o n s t a n t b e h a v i o r on the system f o r a g i v e n socioeconomic group, the b e h a v i o r a l s t u d i e s assume c o n s t a n t v a l u e systems. That i s , the v a l u e of a g i v e n t i m e - c o s t - c o m f o r t r e l a t i o n s h i p w i l l remain c o n s t a n t through time. T h i s assumption may not apply i n the c o n t e x t o f our r a p i d l y changing s o c i a l environment. For example c o s t f a c t o r s do not appear t o weigh h e a v i l y i n the mode c h o i c e d e c i s i o n i n r e l a t i o n to time i n t h i s p e r i o d of a f f l u e n c e . However, i t seems re a s o n a b l e t o expect changes i n r e l a t i v e v a l u e s g i v e n to mode a t t r i b u t e s under new s o c i a l c o n d i t i o n s . T h e r e f o r e mode c h o i c e r e s e a r c h needs to examine the s u b j e c t i v e a s p e c t of d e c i s i o n s through the p r e f e r e n c e s t r u c t u r e s of d i f f e r e n t socioeconomic groups. The Problem of S t r a t i f i c a t i o n There i s a w e l l known co n c e p t u a l l i n k between t r a n s -p o r t a t i o n systems and urban s t r u c t u r e . The t r a n s p o r t a t i o n study has as i t s b a s i s a s p e c i f i c urban form and s t r u c t u r e f o r which t r a n s p o r t a t i o n needs are d e r i v e d . The t r a n s p o r t a t i o n system may under some circumstances i n f l u e n c e l a n d use.* The mode s p l i t model has been t r e a t e d mostly as a sub-model i n the t r a n s p o r t a t i o n p l a n n i n g p rocess i n which the land use l i n k a g e s are handled i n some s e q u e n t i a l l y p r e v i o u s a n a l y s i s : f o r example i n the t r i p g e n e r a t i o n s t a g e . But any, c o n t r o l mechanism which a d j u s t s mode s p l i t , and t h e r e f o r e the r e l a t i v e performance of the system, w i l l s u r e l y have an e v e n t u a l impact on l a n d use and socioeconomic p a t t e r n s . Because of t h i s impact i t i s i m p e r a t i v e t o s t r a t i f y the c o n t r o l mechanism by i t s i n f l u e n c e c a t e g o r i e s . The most d i r e c t of these i s socioeconomic groupings which are r e l a t e d to f u r t h e r s t r u c t u r a l changes. A s y s t e m a t i c attempt to show how the mode c h o i c e v a r i e s w i t h socioeconomic groups has not been attempted. The mode c h o i c e i s simply a m a n i f e s t a t i o n of a bundle of t r a n s p o r -t a t i o n r e l a t e d d e c i s i o n s which i n c l u d e s home and job l o c a t i o n . Thus, the s e r v i c e performance o f a t r a v e l c o r r i d o r w i l l i n f l u e n c e s p a t i a l r e l a t i o n s h i p s and the i n f l u e n c e area o f any c o r r i d o r t r a n s p o r t a t i o n system over the l o n g term w i l l r e f l e c t how the d i f f e r e n t groups v a l u e the system c h o i c e s a v a i l a b l e to them. I f the t r a n s i t s e r v i c e , f o r example, i s good those who v a l u e h i g h l y the 1 combination of a t t r i b u t e s m a n i f e s t e d by the t r a n s i t * T h i s i s not s e l f e v i d e n t . The understanding of t h i s i n f l u e n c e a t b e s t i s o n l y tenuous. s y s t e m w i l l be a t t r a c t e d t o t h e c o r r i d o r . T h i s i l l u s t r a t e s t h e c l o s e r e l a t i o n s h i p b e t w e e n t h e s t r u c t u r e o f t r a n s p o r t a t i o n s e r v i c e a r e a and t h e s e r v i c e p r o v i d e d . T h e r e f o r e any a n a l y s i s o f t r a n s p o r t a t i o n p o l i c y e f f e c t s on c h a n g i n g t h e mode s p l i t must u l t i m a t e l y be r e f l e c t e d i n t h e s o c i o e c o n o m i c g r o u p i n g s o f t h e s e r v i c e a r e a . F u r t h e r m o r e , p r e d i c t i o n s o f mode s p l i t must be r e l a t e d t o a s t r a t i f i c a t i o n o f t h e p o p u l a t i o n s i n c e d i f f e r e n t c o m b i n a t i o n s o f s e r v i c e l e v e l s a r e v i e w e d d i f f e r e n t l y by e a c h s o c i o e c o n o m i c g r o u p i n g . I t w o u l d a p p e a r f r o m t h e l i t e r a t u r e , f o r e x a m p l e , t h a t p o l i c i e s a f f e c t i n g c o s t w o u l d h a v e more i m p a c t on low in c o m e g r o u p s t h a n h i g h income g r o u p s , w h e r e a s p o l i c i e s a f f e c t i n g t r a v e l t i m e may h a v e more e f f e c t on h i g h income g r o u p s . T h i s n e e d has b e e n r e c o g n i z e d i n some mode s p l i t s t u d i e s . ^ ' The em p h a s i s o f t h e s e h a s b e e n on s t r a t i f i c a t i o n by i n c o m e g r o u p s . N o t a b l e i s t h e T r a f f i c P r e d i c t i o n M o d e l w h i c h 75 i s a f a m i l y o f c u r v e s s t r a t i f i e d by in c o m e c l a s s e s . * Zupan a l s o c o n c l u d e d t h a t s e n s i t i v i t i e s t o s e l e c t e d mode s p l i t d e t e r m i n a n t s c h a n g e d w i t h i n c o m e s t r a t i f i c a t i o n and o n l y when income l e v e l d i s t r i b u t i o n was n o t c h a n g i n g r a d i c a l l y w o u l d an u n s t r a t i f i e d e q u a t i o n be a d e q u a t e f o r mode s p l i t f o r e c a s t s . T h e s e m o d e l s a r e l i n e a r r e g r e s s i o n t e s t s t o p r e d i c t t h e p r o p o r t i o n t a k i n g t r a n s i t i n any g i v e n i n c o m e g r o u p b a s e d on t h e e x p l a n a t o r y v a r i a b l e s f o u n d t o be s i g n i f i c a n t f o r e a c h g r o u p . However, as * D e v e l o p e d by T r a f f i c R e s e a r c h C o r p o r a t i o n f o r t h e M e t r o p o l i t a n T o r o n t o P l a n n i n g Board, ( s e e R e f . 3 7 ) . p o i n t e d out by Rulon, l i n e a r r e g r e s s i o n i s not the pr o p e r model s t r u c t u r e to p r e d i c t i n d i v i d u a l membership i n a group based on b e h a v i o r c h a r a c t e r i s t i c s of the i n d i v i d u a l because s t r a t i f i c a t i o n i s performed b e f o r e the t e s t . The problem of mode c h o i c e i s t h a t of group member-s h i p g i v e n a be h a v i o r p a t t e r n on the system of a l l i n d i v i d u a l s measured by time, c o s t , and convenience v a r i a b l e s . The r e l e v a n t q u e s t i o n i s to what group i s an i n d i v i d u a l l i k e l y to belong; t h a t group which uses c a r to commute or t h a t group u s i n g the bus? S i m i l a r l y , i f a s h i f t p r e f e r e n c e p a t t e r n of automobile d r i v e r s f o r system changes i s known to what socioeconomic group does t h i s i n d i v i d u a l belong? T h i s concept can be used to t e s t the s i g n i f i c a n c e o f the s e p a r a t i o n of groups on the b a s i s of how they behave on the system or t h e i r p r e f e r e n c e p r o f i l e . The t e s t i n g of a p r i o r i groups, and the p o s t e r i o r assignment of i n d i v i d u a l s to a group has been c a l l e d the d i s c r i m i n a t i o n -77 c l a s s i f i c a t i o n approach. RESEARCH ASSUMPTIONS The r e s e a r c h i s an e m p i r i c a l i n v e s t i g a t i o n of a case study which c o n s i s t s of a t r a n s p o r t a t i o n c o r r i d o r t e r m i n a t i n g i n the C e n t r a l Business D i s t r i c t of Vancouver, Canada. The i n f l u e n c e area of t h i s c o r r i d o r i s the r e s e a r c h space f o r the study. The s t r u c t u r a l elements which form the b a s i s of the r e s e a r c h space are s e l e c t e d socioeconomic c h a r a c t e r i s t i c s of 4 8 . those who l i v e i n the c o r r i d o r i n f l u e n c e area and use the c o r -r i d o r f o r the journey to work. These' c h a r a c t e r i s t i c s can be d i v i d e d i n t o two c l i e n t groups; t h a t group which use a c a r f o r the journey to work and t h a t group which makes the journey by bus. Each c l i e n t group i s f u r t h e r viewed i n terms of i t s sub-d i v i s i o n i n t o s e v e r a l groups d e f i n e d by t h e i r socioeconomic c h a r a c t e r i s t i c s ; those s e l e c t e d f o r t h i s i n v e s t i g a t i o n b e i n g sex, age, o c c u p a t i o n , c a r ownership and income. The f u n c t i o n a l elements of the r e s e a r c h space i s the t r a n s p o r t a t i o n system c o n s i s t i n g of the f a c i l i t i e s f o r auto t r a v e l and those f o r bus t r a v e l . These are f u r t h e r viewed as a b s t r a c t modes d e f i n e d by the r e l a t i v e performance p r o v i d e d to the CBD f o r each group of c o r r i d o r commuters. Performance f a c t o r s s t u d i e d a n a l y t i c a l l y are o v e r a l l t r a v e l times, excess t r a v e l times, and o u t - o f - p o c k e t expenses. R e l a t i v e comfort of the modes i s a l s o i n v e s t i g a t e d . System performance i s examined i n r e g a r d to both the b e h a v i o r a l and p r e f e r e n c e pro-f i l e s of i n d i v i d u a l s u s i n g the c o r r i d o r f o r commuting to the CBD; i n which an i n d i v i d u a l ' s p r o f i l e c o n s t i t u t e s t h a t combina-t i o n of system a t t r i b u t e s which are s e l e c t e d , or which would be p r e f e r r e d , by a car user to have him change mode. I t i s necessary to s e p a r a t e the v a r i a b l e s i n t o s t r u c -t u r a l and f u n c t i o n a l elements as above to be a b l e to analyse the i n c i d e n c e of the e f f e c t s of t r a n s p o r t a t i o n p o l i c y . P u b l i c d e c i s o n s on t r a n s p o r t a t i o n p r o j e c t s have, among o t h e r s , d i r e c t e f f e c t s on u s e r s . User d i r e c t e f f e c t s r e f e r to the use or non-use, or the change i n mode of the system; t h a t i s , i t i s r e l a t e d to the d e c i s i o n s of the user based on h i s p e r c e p t i o n of the system. But the consequences of any p u b l i c d e c i s i o n i s v a l u e d d i f f e r e n t l y and t h e r e f o r e i t i s necessary to i d e n t i f y those s e c t i o n s o f the p u b l i c who. are a f f e c t e d by each p o l i c y change. T h e r e f o r e each socioeconomic group i s examined as to p o s s i b l e r e l a t i o n s h i p s w i t h the performance of the system. The study i s r e l a t e d to demand f o r t r a v e l between modes. Demand f o r t r a v e l appears to s a t i s f y the c o n d i t i o n s p o s t u l a t e d by the economic theory of d e r i v e d demand.* M a r s h a l l s t a t e s the theory very s u c c i n c t l y . the demand f o r each of s e v e r a l complementary t h i n g s i s d e r i v e d from the s e r v i c e s they j o i n t l y render i n the p r o d u c t i o n o f some u l -timate product.78 In the c o n t e x t of t h i s d e f i n i t i o n t r a n s p o r t a t i o n i s an i n t e r -mediate and complementary s e r v i c e i n the p r o d u c t i o n or consump-t i o n of some good which has d i r e c t v a l u e . The d e r i v e d nature of demand i s accounted f o r i n t r a n s p o r t a t i o n p l a n n i n g by doing * T r a v e l i s o n l y more or l e s s a d e r i v e d demand to the degree t h a t t r i p s and t r a v e l e x p e n d i t u r e s (e.g. car purchase) are not undertaken f o r t h e i r own sake. Thus, the journey to work may be almost e n t i r e l y a d e r i v e d demand f o r the economic n e c e s s i t y of e a r n i n g a wage; whereas an annual motor v a c a t i o n may be demanded almost e n t i r e l y by i t s e l f . A l s o , f o r example, T r o x e l c o n ceives demand f o r movements of people to be r e l a t e d t o "net p r o d u c t s " of t r a v e l i n which j u s t " g e t t i n g out of the house" i s a p o s i t i v e net p r o d u c t of t r a v e l . (See Ref.. 83). 50 . s e p a r a t e a n a l y s e s f o r e a c h t r i p p u r p o s e . I n t h i s s t u d y c o n -c e r n i s w i t h a s i n g l e t r i p p u r p o s e : t h e j o u r n e y t o work. To s t u d y i n t e r m o d a l demand f o r t h e j o u r n e y t o work i n i s o l a t i o n f r o m t h e j o i n t l y demanded c o m p l e m e n t a r y g o o d two a s s u m p t i o n s a r e n e c e s s a r y ; (1) t h a t t h e demand f o r j o b s r e m a i n u n c h a n g e d b o t h i n terms o f i n c i d e n c e and l o c a t i o n , and (2) t h a t t h e r e a r e no c h a n g e s i n t h e s u p p l y o f o t h e r c o m p l e m e n t a r y f a c t o r s . We assume a g i v e n s e t o f t r a v e l h a b i t s , t a s t e s and i n c o m e s ; and a f i x e d l a n d u s e p a t t e r n . T h a t i s , r e s i d e n c e and work p l a c e a r e i n e q u i l i b r i u m v / i t h t r a v e l p a t t e r n s e s t a b l i s h e d a t t h e t i m e o f t h e t r a v e l d e c i s i o n , where no i n d i v i d u a l i s p l a n n i n g t o c h a n g e e i t h e r j o b o r r e s i d e n c e l o c a t i o n . The demand f u n c t i o n t h e n i n c o r p o r a t e s two d e c i s i o n s — w h e t h e r o r n o t t o make t h e t r i p a t a l l , and what mode t o u s e . The f i r s t d e c i s i o n d e p e nds upon t h e a n t i c i p a t e d r e w a r d s o f t r a v e l t o a s p e c i f i c l o c a t i o n f o r a s p e c i f i c p u r p o s e . The v a l u e p l a c e d on t h e p e r -c e i v e d r e w a r d s o f t h e t r i p w i l l d e t e r m i n e t h e g e n e r a l i z e d p r i c e an i n d i v i d u a l i s w i l l i n g t o e x c h a n g e i n a t r a d e - o f f w i t h a l l o t h e r e x p e n d i t u r e s , w i t h i n t h e c o n s t r a i n t s o f a f i x e d b u d g e t and s o c i o e c o n o m i c and c u l t u r a l makeup. T h i s component o f t r a v e l demand i s a n a l o g o u s t o t h e t r i p g e n e r a t i o n and d i s t r i b u t i o n a s p e c t s o f t h e t r a n s p o r t a t i o n p l a n n i n g p r o c e s s . F o r t h e p r e s e n t s t u d y t h e g e n e r a t i o n / d i s t r i b u t i o n component i s c o n t r o l l e d by c o n s i d e r i n g o n l y t h e work t r i p , and by a s s u m i n g t h a t work p l a c e i s i n s p a t i a l e q u i l i b r i u m w i t h r e s i d e n c e . T h a t i s , t h e number of work t r i p s to any geographic area i s equal to the number of jobs i n t h a t area and a decrease i n t r a n s p o r t a t i o n c o s t s or t r a v e l time w i l l not i n c r e a s e the number of t r i p s but change onl y the modal s p l i t . The remaining component of the demand a n a l y s i s (the mode choice) w i l l depend upon the socioeconomic c h a r a c t e r i s t i c s of the b e h a v i o r a l u n i t , * and the a t t r i b u t e s of the modes a v a i l -a b l e . These a c t i n t e r d e p e n d e n t l y to produce the c h o i c e of mode. The a t t r i b u t e s o f the mode can ent e r i n t o the a n a l y s i s as ab-s o l u t e v a l u e s of the b e s t combination of a t t r i b u t e s f o r the s e t of socioeconomic c h a r a c t e r i s t i c s i n q u e s t i o n ; or as r e l a t i v e v a l u e s of the mode used to i t s a l t e r n a t i v e ( s ) . (See f o r example Quandt and Baumol whose model i n c o r p o r a t e s both these measures 79 s i m u l t a n e o u s l y ) . The i n t e r a c t i o n o f the i n d i v i d u a l s o c i o -economic c h a r a c t e r i s t i c s w i t h the a t t r i b u t e s of the mode which shows the b e s t p e r c e i v e d c h a r a c t e r i s t i c s w i t h i n a g i v e n s e t of c h a r a c t e r i s t i c s f o r those with a c h o i c e o f mode d e f i n e s the demand f u n c t i o n f o r mode s p l i t . The concept of i s o l a t i n g a study of i n t e r m o d a l demand to the CBD from t o t a l demand f o r t r a v e l appears r e a s o n a b l e , a t l e a s t f o r l a r g e r c i t i e s . I t has been observed t h a t employment * I t would appear t h a t demand a l s o stems i n p a r t from d i r e c t c u l t u r a l p r e - c o n d i t i o n i n g which, i t can be argued, c o u l d have s u b s t a n t i a l c a u s a l r e l a t i o n s h i p to mode c h o i c e . T h i s f a c -t o r has not been taken i n t o account i n t h i s study, but con-s i d e r e d as homogeneous acr o s s the p o p u l a t i o n . i n the c e n t r a l c i t y areas s t a b i l i z e s when the p o p u l a t i o n of 8 0 the r e g i o n approaches 1 m i l l i o n . F l u c t u a t i o n s i n CBD a c t i v i t i e s are such t h a t i n many cases cordon counts of people 81 e n t e r i n g (or l e a v i n g ) the CBD each day i s v i r t u a l l y c o n s t a n t . These trends have been accompanied w i t h a mode s h i f t away from p u b l i c t r a n s i t to automobile. S t u d i e s the author has conducted i n Toronto show t h a t between 1950 and 1965 entrances were con-s t a n t and the i n c r e a s e i n person t r i p s e n t e r i n g by c a r was 8 2 e x a c t l y e q u i v a l e n t to the decrease by t r a n s i t . While not c o n c l u s i v e f o r any p a r t i c u l a r urban r e g i o n , there i s t h e r e f o r e some evidence t o support the study of mode s p l i t t o the CBD more or l e s s s e p a r a t e l y from the s p a t i a l and land use i m p l i -c a t i o n . CHAPTER I I I DESCRIPTIVE ANALYSIS OF CASE STUDY DATA PREPARATION Data f o r the i n v e s t i g a t i o n c o n s i s t of a m o d i f i e d o r i g i n d e s t i n a t i o n survey of commuters from the "North Shore" communi-t i e s who c r o s s the F i r s t Narrows B r i d g e t o the CBD of Vancouver.* The "North Shore" of the Vancouver m e t r o p o l i t a n r e g i o n c o n s i s t s of a number of communities o r g a n i z e d i n t o three m u n i c i p a l i t i e s : the M u n i c i p a l i t y of West Vancouver, the C i t y of North Vancouver, and the D i s t r i c t of North Vancouver. The most r e c e n t Census (1966) g i v e s a combined p o p u l a t i o n of 106,962 (31,987; 26,851; 48,124 r e s p e c t i v e l y ) . In most aspects important to t h i s study the m u n i c i p a l i t i e s are t y p i c a l suburban communities, w i t h the e x c e p t i o n of p a r t s of West Vancouver which have developed i n t o h i g h d e n s i t y bedroom r e s i d e n t i a l areas f o r h i g h s t a t u s CBD employees. Thus, incomes i n West Vancouver are s u b s t a n t i a l l y h i g h than the average f o r the m e t r o p o l i t a n r e g i o n , and t h i s m u n i c i p a l i t y i s c h a r a c t e r i z e d by a h i g h e r p r o p o r t i o n of managers and p r o f e s s i o n a l employees than the r e g i o n as a whole. The communities are s e p a r a t e d from the CBD of Vancouver by B u r r a r d I n l e t which i s c r o s s e d by two b r i d g e s : the L i o n ' s *See Appendix A. Gate suspension b r i d g e a t the F i r s t Narrows; and the Second Narrows B r i d g e . The former b r i d g e connects West Vancouver with the CBD, w h i l e the l a t t e r c r o s s i n g i s some 5 1/2 m i l e s to the e a s t . The focus of t h i s i n v e s t i g a t i o n i s on the commuters who c r o s s e d the F i r s t Narrows B r i d g e between 7am and 9am on a week-day i n March 1967. While t h e r e i s some d i v e r s i o n of automobile t r a f f i c from the western p a r t of the study area to the Second Narrows B r i d g e because of s a t u r a t i o n volumes on the F i r s t Narrows B r i d g e , these b r i d g e s e s s e n t i a l l y d e f i n e two s e p a r a t e t r a v e l c o r r i d o r s ; the F i r s t Narrows B r i d g e s e r v i n g commuters to the CBD, as w e l l as a s u b s t a n t i a l number of those going p a s t the CBD; and the Second Narrows B r i d g e s e r v i n g areas to the e a s t of the CBD. T r a f f i c volumes on the F i r s t Narrows B r i d g e d u r i n g the morning peak p e r i o d of 7-9am vary between about 6,200 v e h i c l e s per hour i n mid week to about 6,500 on Mondays and F r i d a y s . Peak hour volumes are about 50 p e r c e n t of t h e s e . The h o u r l y r a t e of flow based on 15 minute counts peaks a t 3,400, t h i s r a t e remaining more or l e s s c o n s t a n t between about 7:15 and 8:45 and r e p r e s e n t s s a t u r a t e d flow and the l i m i t i n g capa-c i t y of the B r i d g e . * Flow speeds are about 20mph under these t r a f f i c c o n d i t i o n s . The North Shore i s s e r v e d by two d i f f e r e n t bus s e r -v i c e s ; the B r i t i s h Columbia Hydro A u t h o r i t y buses, and those of *These s t a t i s t i c s are based on counts taken Feb. 4, 1 9 6 7 - Feb. 10, 1 9 6 7 by N.D. Lea and A s s o c i a t e s (see Ref. 1). . the West Vancouver M u n i c i p a l T r a n s p o r t a t i o n System. During the two hour morning peak i n 1967 (at the time of the survey) 30 Hydro and 22 West Vancouver buses c a r r i e d 2,490 persons, most of whom were d e s t i n e d to the CBD; 1,633 v i a BC Hydro S e r v i c e and 857 v i a West Vancouver s e r v i c e . At the time of the survey buses c a r r i e d 21.8 p e r c e n t of the t o t a l of 11,140 persons a c r o s s the B r i d g e i n the peak p e r i o d from 6:45-9:15am. S i n c e the f a l l of 1967 buses have been g i v e n p r i o r i t y a t the Bridge-head, and allowed t o use a s e p a r a t e c o l l e c t o r lane to f a c i l i t a t e e n t r y to the B r i d g e . T h i s has improved bus t r a v e l times and patronage.* Data Reduction The study data c o n s i s t of the r e s u l t s of a s e p a r a t e bus and automobile survey of commuters on the B r i d g e d u r i n g the morning peak p e r i o d i n March, 1967; conducted by N.D. Lea and A s s o c i a t e s f o r the B.C. Highways Department. Q u e s t i o n -n a i r e s * * were d i s t r i b u t e d to a l l bus r i d e r s , and 80 p e r c e n t of 2 c a r d r i v e r s and passengers between 6:45 and 9:15am. Bus ques-t i o n n a i r e s were d i s t r i b u t e d by the d r i v e r s to a l l passengers, w h i l e auto q u e s t i o n n a i r e s were handed to the d r i v e r a t the Bridge-head. The q u e s t i o n n a i r e s were to be r e t u r n e d by m a i l w i t h i n a week, wit h o v e r a l l response r a t e 58 p e r c e n t of the bus and 49 p e r c e n t of the c a r q u e s t i o n n a i r e s r e t u r n e d . * * * The *Mr. D.W. M i l l s of B.C. Hydro estimates t h a t t r a n s i t r i d e r s h i p i n c r e a s e d 15-20 p e r c e n t because of the improved s e r v i c e . **See Appendix B * * * A c t u a l l y 65 p e r c e n t of c a r passengers d e s t i n e d to the CBD who r e c e i v e d a q u e s t i o n n a i r e r e t u r n e d a u s e f u l response, thereby b r i n g i n g the r e l a t i v e response r a t e s c l o s e to the pro-p o r t i o n of users of each mode even though a s m a l l e r p r o p o r t i o n of c a r d r i v e r s were o r i g i n a l l y sampled. survey responses were coded and put on punched cards by the survey agency and d u p l i c a t e s of these cards were made a v a i l a b l e to the author. A f t e r e d i t i n g and e l i m i n a t i n g non-work purpose t r i p s , 3,776 u s e f u l i n t e r v i e w s c o n s t i t u t e d the sample f o r t h i s i n v e s t i g a t i o n . These t r i p s were s u b d i v i d e d i n t o the two modes, and f u r t h e r s u b d i v i d e d i n t o those t r i p s to the CBD and those d e s t i n e d to non-CBD l o c a t i o n s . A summary of the response i s g i v e n below. Mode D e s t i n a t i o n No. of Responses i n Sample Percentage of T r a n s i t Mode i n Sample CAR CBD 1,607 42.5 BUS CBD 1,185 CAR NON-CBD 875 11.1 BUS NON-CBD 109 The 42.5 p e r c e n t sample p r o p o r t i o n of t r a n s i t response to t o t a l sample response i s reasonably c l o s e to the p r o p o r t i o n of t r a n s i t r i d e r s to t o t a l commuters to the CBD. Reported average p r o p o r t i o n of t r a n s i t t r i p s to a l l person t r i p s to the CBD i n peak p e r i o d s are about 35 p e r c e n t (N.D. Lea r e p o r t s 33 pe r c e n t of a l l person t r i p s a cross the b r i d g e i n the peak p e r i o d 3 are t r a n s i t p a s s e n g e r s ) . The d e c i s i o n was made to accept w i t h -out f u r t h e r adjustment the sampled p r o p o r t i o n found i n the t o t a l commuter p o p u l a t i o n . The o v e r a l l sample response r a t e of 34 p e r c e n t of person t r i p s i n the c o r r i d o r i s h i g h f o r a m a i l e d q u e s t i o n n a i r e and t h e r e f o r e was c o n s i d e r e d a s a t i s f a c t o r y data base f o r the p r e s e n t i n v e s t i g a t i o n . The car and bus modes to the CBD were combined and the r e s u l t a n t sample of 2,792 s u b j e c t s became the primary d a t a f o r i n v e s t i g a t i o n . This data base d i f f e r s from a t y p i c a l o r i g i n d e s t i n a -t i o n survey and r e q u i r e s some e x p l a n a t i o n . Measurements are taken on the modal c h a r a c t e r i s t i c s , r a t h e r than on household c h a r a c t e r i s t i c s as i s the u s u a l p r a c t i c e i n 0-D s u r v e y s . That i s , the c l i e n t s of each mode were asked t h e i r t r a v e l h a b i t s and household c h a r a c t e r i s t i c s w h i l e engaged i n a s i n g l e t r i p , t h e i r journey to work; whereas i n the home i n t e r v i e w o r i g i n d e s t i n a t i o n study the complete t r i p making p a t t e r n i s surveyed, u s u a l l y f o r the day b e f o r e the survey. The p r e s e n t survey may t h e r e f o r e produce more a c c u r a t e r e s u l t s i n d e t e r m i n i n g the c h a r a c t e r i s t i c s of the modes, t h e i r d i f f e r e n c e s , and i n p a r t i -c u l a r the s t r u c t u r e of t h e i r c l i e n t groups and the r e l a t i o n s h i p between modal c l i e n t group s t r u c t u r e and modal c l i e n t group s t r u c t u r e and modal a t t r i b u t e s . T h i s type of survey, however, w i l l a l l o w only l i m i t e d g e n e r a l i z a t i o n s to be made about the mode s p l i t of d i f f e r e n t s t r u c t u r a l combinations. That i s , the survey i s more u s e f u l to e x p l o r e the c h a r a c t e r i s t i c s of a p a r t i c u l a r mode than to p r e d i c t mode s p l i t from urban s t r u c -t u r a l c o n d i t i o n s , a g e n e r a l p r a c t i c e used i n a n a l y z i n g home i n t e r v i e w s t u d i e s . 58. Furthermore, measurements of t r a v e l dimensions are e n t i r e l y i n terms of s u b j e c t i v e responses. T h i s allows an examination of the d i r e c t r e l a t i o n s h i p s between user c a l c u l u s and the mode c h o i c e . The m a i l e d q u e s t i o n n a i r e i s sometimes s u b j e c t to response b i a s . The survey agency a n t i c i p a t e d t h i s and an independent c o n s u l t a n t performed a f o l l o w - u p home i n t e r v i e w telephone check survey to es t i m a t e f o r b i a s . A random sample of 313 households were asked whether or not a c a r q u e s t i o n n a i r e was r e c e i v e d and r e t u r n e d , and whether or not the B r i d g e was normally used d u r i n g the morning peak p e r i o d of 7am-9am. The punched cards with the survey response were made a v a i l a b l e to the author, and a Chi-square contingency t e s t performed to t e s t the v a l i d i t y of the sample i n r e p r e s e n t i n g the t o t a l p o p u l a t i o n of automobile commuters shows t h a t the sample responses and the t o t a l number of commuters who normally use the b r i d g e i n the peak p e r i o d are not s i g n i f i c a n t l y d i f f e r e n t (Table I ) . The l a r g e s t c o n t r i b u t i o n to the Chi-square s t a t i s t i c are zones E, F,G which are h i g h socioeconomic s t a t u s areas which have a h i g h e r than average response r a t e ; a t y p i c a l s i t u a t i o n i n most sample surveys of t r a f f i c * The data were reduced f o r f u r t h e r a n a l y s i s i n two ways. A m u l t i v a r i a t e t a b u l a t i o n procedure, u s i n g the MVTAB, U.B.C. *See Appendix A. T a b l e I CHI-SQUARE CONTINGENCY TEST OF CAR SAMPLE V A L I D I T Y , NUMBER OF RESPONSES I N EACH CATEGORY SHOWN USE BRIDGE, USE BRIDGE, ZONE RECEIVED AND BUT DIDN'T DO NOT CONTRIBUTION RETURNED RECEIVE USE TO QUESTIONNAIRE QUESTIONNAIRE BRIDGE CHI-SQUARE A,B,C,D 5 6 21 .01 E 4 0 5 1.20 F,G 9 3 20 2.37 H 5 8 7 .06 I 6 7 12 .12 J , K , L 4 6 9 .03 M,N,0 4 13 22 .55 P,Q,R,S 5 • 10 39 .15 T,U,V,W,X 5 15 37 .36 TOTAL 47 68 172 X 2 = 4.85 d . f . 8 p * > .70 *p, i n t h i s a n d o t h e r t a b l e s i s t h e p r o b a b i l i t y o f m a k i n g a n e r r o r i n r e j e c t i n g t h e n u l l h y p o t h e s i s o f no d i f f e r e n c e . 6 0 . l i b r a r y program f o r the IBM 360/67 computer, was used to analyze the q u e s t i o n n a i r e responses and form the b a s i s of the a n a l y s i s i n t h i s c h a p t e r . The data were a l s o r e f o r m a t t e d f o r f u r t h e r m u l t i v a r i a t e s t a t i s t i c a l a n a l y s i s . T h i s procedure i s d i s c u s s e d i n the next chapter. MODE SPLIT AND THE SOCIOECONOMIC STRUCTURE  OF COMMUTERS Thi s i n v e s t i g a t i o n i s d i r e c t e d toward the a n a l y s i s of the socioeconomic space of commuters to the CBD, but a b r i e f a n a l y s i s of the r e l a t i o n s h i p s between CBD commuters and non-CBD commuters i s g i v e n below as a c o n t e x t u a l framework f o r the f u r t h e r a n a l y s i s of CBD commutation and mode c h o i c e . I t i s c l e a r t h a t both socioeconomic c h a r a c t e r i s t i c s and the r e l a t i v e a c c e s s i b i l i t y of the CBD by v a r i o u s modes a v a i l a b l e are f a c t o r s d i f f e r e n t i a t i n g the CBD commuter from the non-CBD commuter. The i m p l i c a t i o n i s t h a t any g e o g r a p h i c a l area of t r a v e l g e n e r a t i o n may be h y p o t h e t i c a l l y dimensioned i n -to two socioeconomic spaces; t h a t space which d i f f e r e n t i a t e s those commuting to the CBD from those which do not; and t h a t space which d i f f e r e n t i a t e s those who use t r a n s i t from those who use automobiles. A comparison of the socioeconomic c h a r a c t e r i s t i c s of those who commute to the CBD w i t h those who pass through or around the CBD shows some d i f f e r e n c e s (Table I I ) . P r o p o r t i o n -a t e l y fewer males commute to the CBD than to o t h e r d e s t i n a t i o n s . 6 1 . T a b l e I I PERCENT OF EACH SOCIOECONOMIC GROUP COMMUTING TO CENTRAL BUSINESS D I S T R I C T LOCATIONS COMPARED TO OTHER DESTINATIONS, BY CAR AND BY BUS PERCENT SOCIOECONOMIC CENTRAL OTHER GROUP BUSINESS DIST . DESTINATIONS BY C A R a B U S b A L L BY C A R C BY BUS d A L L SEX: MALE 88.1 58.3 73.2 83.9 39. 8 79.3 FEMALE 11.9 41.7 26.8 16.1 60. 2 20.7 AGE: 0 - 2 0 2.2 9.3 5.2 1.5 12. 8 2.7 21 - 40 42.2 45.9 43 .9 43 .4 36. 8 42.7 41 - 60 52.2 40.6 47.2 51.6 47 . 7 51.5, OCCUPATION: MANAGERIAL 37.0 16.8 28.5 34.0 10. 1 31.4 PROFESSIONAL 30.0 27.7 29.2 31.0 15. 6 29.2 SECRETARIAL 5.2 30.8 16.0 4.6 37 . 6 8.3 C L E R I C A L 9.5 5.5 7.8 5.6 5. 5 5.6 SALES 12.8 18.8 15.2 13.5 20. 2 19.2 OTHER 5.5 0.4 3.3 11.3 1 1 . 0 11.3 CAR OWNERSHIP NONE 0.7 9.2 4.4 0.4 17. 8 2.4 ONE 42.0 67.3 52.9 37.0 63 . 5 40.0 TWO 50.5 21.2 38.0 55.3 14. 0 50.6 THREE OR MORE 7.0 2.3 4.2 7.3 4. 7 7.0 INCOME 4,000 6.4 30.0 15.6 7.3 43 . 6 11.4 4,000-8,000 25.9 41.7 32.7 34.4 48. 1 36.0 8,000-12,000 34.8 22.9 29.6 35.2 6. 5 32.0 12,000 33 .0 7.4 22.1 23.1 1. 8 20. 6 a. 1,607 r e s p o n s e s b. 1,185 r e s p o n s e s c. 875 r e s p o n s e s d. 109 r e s p o n s e s More s e c r e t a r i e s , c l e r k s and s a l e s people commute to the CBD, w h i l e low s t a t u s trades and s e r v i c e workers predominate f o r non-CBD d e s t i n a t i o n s . M a n a g e r i a l and p r o f e s s i o n a l workers are about evenly s p l i t , w ith managers showing a s l i g h t l y g r e a t e r p r o p e n s i t y t o t r a v e l beyond the CBD. The CBD commuter i s s l i g h t l y younger than the non-CBD one. In comparing c a r ownership and incomes o f CBD com-muters w i t h non-CBD ones i t i s apparent t h a t those commuters to the CBD have fewer cars and s l i g h t l y lower incomes. The median number of ca r s per household f o r commuters to the CBD i s 0.86 whereas i t i s 1.15 f o r non-CBD commuters. Median i n -come i s 10,350 f o r CBD commuters and 10,750 f o r non-CBD com-muters. The Chi-square s t a t i s t i c shows t h a t the d i f f e r e n c e s found are s i g n i f i c a n t * except f o r sex d i f f e r e n t i a t i o n (Table I I I ) . Ta b l e I I I SIGNIFICANCE TEST OF SOCIOECONOMIC CHARACTERISTICS OF CBD COMMUTERS VERSUS NON-CBD COMMUTERS CHARACTERISTIC D.F. x 2 P SEX 1 2.87 10 AGE 3 16.03 01 OCCUPATION 5 125.01 001 CAR OWNERSHIP 3 80.08 001 INCOME 3 12.95 01 • S t a t i s t i c a l s i g n i f i c a n c e i s d e f i n e d i n t h i s study as p < .05. A s u b s t a n t i a l p o r t i o n of the v a r i a t i o n i n s o c i o -economic c h a r a c t e r i s t i c s between CBD and non-CBD commuters i s e x p l a i n e d by the r e l a t i o n s h i p between these c h a r a c t e r i s t i c s and mode used. G e n e r a l l y w h i l e t h e r e are s m a l l d i f f e r e n c e s i n commuters f o r a g i v e n mode, l a r g e v a r i a t i o n s occur i n the charac-t e r i s t i c s of those u s i n g d i f f e r e n t modes. For example male commuters dominate the car mode r e g a r d l e s s of whether the d e s t i n a t i o n i s i n the CBD or not, w h i l e o n l y s l i g h t l y outnum-b e r i n g females who go to the CBD by bus. Females a c t u a l l y dominate the bus mode to non-CBD l o c a t i o n s . C a u t i o n however, i s needed i n i n t e r p r e t i n g these s t a t i s t i c s s i n c e non-CBD bus t r a v e l r e p r e s e n t s a very s m a l l p r o p o r t i o n of t o t a l non-CBD t r a v e l (109 t r i p s o r 11.1 p e r c e n t of a l l non-CBD t r i p s ) . The d i s p r o p o r t i o n a t e number of females t o non-CBD l o c a t i o n s may be due to p i c k i n g up low s t a t u s , p a r t - t i m e employees, and those p r o v i d i n g domestic s e r v i c e s i n the sample, w h i l e m i s s i n g manu-f a c t u r i n g workers who t r a v e l t o the suburban l o c a t i o n s but d i d not use the B r i d g e . Younger age groups use the bus and the v a r i a t i o n between CBD and non-CBD groups w i t h i n each mode i s s m a l l . Sub-s t a n t i a l l y more "other" employees (presumably craftsman, l a b o u r e r s and s e r v i c e workers) take the bus to non-CBD l o c a -t i o n s , w h i l e fewer managers do so. Non-CBD bus commuters have fewer c a r s and lower incomes than t h e i r c o u n t e r p a r t who commutes to the CBD. T h i s i s i n d i r e c t c o n t r a s t to the somewhat h i g h e r incomes and c a r ownership of a l l non-CBD commuters, and i n d i -c a tes the importance of the car mode f o r commuting o u t s i d e the CBD. The f i n d i n g s i n d i c a t e t h a t the CBD commuter has a unique socioeconomic space which i s d i f f e r e n t i a t e d from those i n the t r a v e l c o r r i d o r who do not commute to the CBD. F urthe more, i n f e r e n c e s can be made r e g a r d i n g the v a r i a t i o n i n the socioeconomic space of the CBD commuter due to the mode used. The f o l l o w i n g s e c t i o n s e n l a r g e upon these i n f e r e n c e s . Socioeconomic C h a r a c t e r i s t i c s S u b s t a n t i a l d i f f e r e n c e s e x i s t between those who use c a r and those who use the bus. One way of c o n s i d e r i n g these d i f f e r e n c e s i s to v i s u a l i z e the c l i e n t s of the same mode as c o n s i s t i n g of a number of i n d i v i d u a l s w i t h r e l a t i v e l y homo-geneous c h a r a c t e r i s t i c s , w h i l e the c l i e n t group c h a r a c t e r i s -t i c s of d i f f e r e n t modes are r e l a t i v e l y heterogeneous. The degree of h e t e r g e n e i t y ( v a r i a t i o n between users of d i f f e r e n t modes) to homogeneity ( v a r i a t i o n of i n d i v i d u a l socioeconomic c h a r a c t e r i s t i c s f o r the same mode) can be used as a means of d e f i n i n g the d i f f e r e n c e s of the modes. Chi-square s t a t i s t i c a l t e s t s i n d i c a t e t h a t a l l c h a r a c t e r i s t i c s c o n s i d e r e d are s i g n i f i c a n t i n e x p l a i n i n g the d i f f e r e n c e s between those who use c a r s and those who take t r a n s i t . The r e s u l t of t h i s t e s t i s shown below (Table I V ) . Table IV SIGNIFICANCE TEST OF SOCIOECONOMIC CHARACTERISTICS OF CAR USERS VERSUS TRANSIT RIDERS CHARACTERISTIC D.F. 2 X P SEX 1 438.5 P < .001 AGE 3 87.5 P < .001 OCCUPATION 5 407.4 P < .001 CAR OWNERSHIP 3 385.4 P < .001 INCOME 3 482.1 P < .001 F i g u r e 1 i n d i c a t e s t h a t males g r e a t l y outnumber females i n u s i n g the c a r f o r the journey to work, but females c o n s t i t u t e c l o s e to h a l f of a l l those who t r a v e l by bus. The c o n c l u s i o n t h a t the female l a b o u r f o r c e i s t r a n s i t o r i e n t e d i s supported by v i r t u a l l y a l l s t u d i e s which have i n v e s t i g a t e d sex and mode s p l i t . F i g u r e 2 shows t h a t the g r e a t e r p r o p o r t i o n o f c l i e n t s of the c a r mode are between 41 and 60; whereas bus passengers are more l i k e l y to be under 41, or over 60. Those who have r e c e n t l y e n t e r e d the labour market (probably w i t h o u t a c a r , and perhaps w i t h o u t a d r i v e r s l i c e n s e ) , and those too o l d to d r i v e , or f i n d i t tiresome or who may never have had a d r i v e r s l i c e n s e or automobile, are t r a n s i t p a t r o n s . The f i g u r e a l s o i n d i c a t e s PERCENT IN EACH CATEGORY SHOWN 100 90 80 70 60 50 40 30 20 10 0 MALE FEMALE COMMUTERS CAR BUS MALES FEMALES 1,388 189 686 488 FIGURE 1 SEX CHARACTERISTICS OF COMMUTERS TO CBD, BY MODE USED PERCENT IN EACH CATEGORY SHOWN 100 -90 -80 -70 -60 * 50 " 40 " 30 -20 -10 -0 -O CQ U CQ 0-20 21-40 41-60 > 60 AGE CATEGORY COMMUTERS CAR BUS 0 - 20 34 110 21 - 40 666 543 41 - 60 822 481 > 60 54 47 FIGURE 2 AGE CHARACTERISTICS OF COMMUTERS TO CBD, BY MODE USED 68 . t h a t a l a r g e p r o p o r t i o n of bus r i d e r s are i n the 21-40 age group, an age group which would be expected not to have the b a r r i e r s of c h o i c e imposed upon the younger and o l d e r employee. I t i s apparent t h a t a g r e a t number of these c o n s t i t u t e those who p r e f e r the bus. In comparing the o c c u p a t i o n s of the two c l i e n t groups, some seemingly c o n t r a d i c t o r y t e ndencies emerge ( F i g u r e 3 ) . F i r s t , almost 45 p e r c e n t of bus patrons are i n the h i g h s t a t u s p r o f e s s i o n a l and managerial o c c u p a t i o n a l c a t e g o r i e s . No s y s t e -matic s t u d i e s are a v a i l a b l e of the r e l a t i o n s h i p between mode c h o i c e and o c c u p a t i o n , but fragmentary evidence suggests t h a t h i g h s t a t u s o ccupations ( i n c l u d i n g concomitant h i g h incomes, e d u c a t i o n a l l e v e l s and c a r ownership r a t e s ) are a s s o c i a t e d 4 w i t h the use of the c a r f o r the journey to work. Although the automobile i s the p r i n c i p a l mode f o r m a n a g e r i a l and pro-f e s s i o n a l employees (as can be seen by comparing columns f o r each of these c a t e g o r i e s ) , a s i g n i f i c a n t number of those who r i d e the bus are i n the p r o f e s s i o n a l c a t e g o r y . Secondly, a h i g h p r o p o r t i o n o f c a r passengers are i n the "ot h e r " c a t e g o r y which i n c l u d e s u n s k i l l e d craftsmen, l a b o u r e r s e t c . As expected t h e r e are r e l a t i v e l y few of t h i s c l a s s d e s t i n e d t o the CBD but v i r t u a l l y a l l of those which are, go by c a r (94.5 p e r c e n t ) . Car ownership amongst u n i o n i z e d u n s k i l l e d workers, may account f o r the l a r g e r p r o p o r t i o n of l a b o u r e r s u s i n g the c a r mode than t h a t u s i n g the t r a n s i t mode. 69. 100 -90 -80 -70 -60 ~ PERCENT IN EACH CATEGORY SHOWN 50 -40 -30 -20 -10 -0 ffl CO D « CO. < D U PQ CO o ca « CO n PROFESSIONAL CLERICAL OTHER MANAGERIAL • SECRETARIAL SALES OCCUPATION CATEGORY COMMUTERS BY CAR BY BUS MANAGERIAL 582 192 PROFESSIONAL 476 315 SECRETARIAL 82 351 CLERICAL 149 62 SALES 201 213 OTHER 8 5 5 FIGURE 3 OCCUPATIONAL CHARACTERISTICS OF COMMUTERS TO CBD, BY MODE USED 70. C l e r i c a l s t a f f , a l s o normally a heavy user of t r a n s i t shows a s u b s t a n t i a l percentage u s i n g cars to work. T h i s may be due to the same f a c t o r s as t h a t suggested f o r u n s k i l l e d l a b o u r e r s . S e c r e t a r i a l workers show the u s u a l heavy use o f t r a n s i t and i s p r o b a b l y due more to the f a c t t h a t s e c r e t a r i e s are mostly women, which have a h i g h p r o p o r t i o n of n o n - d r i v e r s , than to any i n h e r e n t o c c u p a t i o n a l c h a r a c t e r i s t i c of s e c r e t a r i e s which d i f f e r from l i k e - s a l a r i e d employees (say c l e r i c a l ) . S a l e s workers appear to be s l i g h t l y more o r i e n t e d to t r a n s i t than to c a r . There may be some r e p o r t i n g i n a c c u r a c i e s i n t r o d u c e d i n the s a l e s / c l e r i c a l c a t e g o r i e s , which may account f o r the r e l a t i v e low use of the bus by c l e r k s and the r e l a t i v e l y h i g h use by s a l e s p e o p l e . S i n c e the responses were s e l f -a d m i n i s t e r e d , people i n these two c a t e g o r i e s would tend to answer t h i s q u e s t i o n by i n d i c a t i n g the category they f e l t t o be the more p r e s t i g o u s . I f s a l e s was more p r e s t i g o u s to them than c l e r k they would probably r e p o r t s a l e s as t h e i r o c c u p a t i o n . In most socioeconomic index s c a l e s c l e r i c a l employment ranks ahead of s a l e s workers i n s o c i a l p r e s t i g e . ^ T h i s i s p a r t i c u -l a r l y the case i f stenographers and s e c r e t a r i e s are i n c l u d e d i n the c l e r i c a l c l a s s i f i c a t i o n , as they are i n the U.S. Census. Only t e n t a t i v e c o n c l u s i o n s may be drawn here s i n c e these c l a s s i -f i c a t i o n s are not w e l l d e f i n e d . I t appears on the evidence t h a t those who c o n s i d e r themselves s e c r e t a r i e s (probably a minimum amount of c o n f u s i o n e x i s t s i n t h i s c a t e g o r y ) , and those who c o n s i d e r themselves s a l e s people are bus o r i e n t e d ; whereas those who c o n s i d e r themselves c l e r i c a l workers are c a r o r i e n t e d . Again i t may be t h a t more s a l e s people are women than i s the case f o r c l e r k s , r e s u l t i n g i n the bus o r i e n t a t i o n found i n t h e i r c l a s s . A s u r p r i s i n g f a c t o r ( F i g u r e 4) i s the h i g h r a t e of car ownership amongst those u s i n g the bus. T h i s c o u l d be due to two f a c t o r s : t h e r e are more a d u l t workers than cars i n a s u b s t a n t i a l number of f a m i l i e s , or some commuters f i n d the bus a d e s i r a b l e a l t e r n a t i v e to the c a r f o r the work journey, thus a l l o w i n g them to le a v e the car a t home f o r shopping and s c h o o l t r i p s . The f a c t t h a t a l a r g e p r o p o r t i o n (21.2 percent) of bus r i d e r s come from 2 c a r f a m i l i e s would i n d i c a t e t h a t c o m p e t i t i o n amongst f a m i l y members f o r c a r s may not be a major f a c t o r ; although undoubtable i n some of the h i g h d e n s i t y apartment areas i n West Vancouver w i t h c h i l d l e s s f a m i l i e s and both hus-band and w i f e working, the c o m p e t i t i o n f o r a s i n g l e c a r i s g r e a t . The c o n c l u s i o n s reached here i s t h a t a s i g n i f i c a n t num-ber of commuters take the bus, even i f a c a r i s t h e o r e t i c a l l y a v a i l a b l e . Another s i g n i f i c a n t f a c t o r i s the hig h o v e r a l l r a t e of c a r ownership, wi t h 95.7 p e r c e n t of those f a m i l i e s i n t e r -viewed owning a t l e a s t one c a r , and 43.5 p e r c e n t owning two or more. These r a t e s are very h i g h . For example, Lansing's study of automobile ownership based on a sample of the p o p u l a t i o n 72. PERCENT I N EACH CATEGORY SHOWN 100 -90 -80 -70 -60 -50 -40 -30 -20 -10 -0 — i% Ui U CQ NONE CO D CQ 04 co <: D U CQ ONE TWO THREE OR + CAR OWNERSHIP CATEGORY AUTOS OWNED PER HOUSEHOLD COMMUTERS BY CAR BY BUS NONE ONE TWO THREE OR MORE 11 662 795 110 109 795 249 27 FIGURE 4 CAR OWNERSHIP CHARACTERISTICS OF COMMUTERS TO CBD, BY MODE USED 73 . of c o n t i n e n t a l U n i t e d S t a t e s shows r a t e s as h i g h as these i n only the h i g h e s t income b r a c k e t s , and even a t t h a t f o r onl y c e r t a i n y e a r s . A l s o the area of i n v e s t i g a t i o n w i t h a c a r 7 ownership r a t e of 1.39 i s h i g h e r than the o v e r a l l r a t e f o r m e t r o p o l i t a n Vancouver r e g i o n , which i s 1.12.* T h i s average f o r the "North Shore" communities i s exceeded i n onl y 7 zones of the remaining 59 t r a f f i c zones of M e t r o p o l i t a n Vancouver. The p r o p o r t i o n s of those of d i f f e r e n t incomes a t t r a c -ted to the c a r mode and bus mode are as expected with income groups towards the high end of the s c a l e f a v o u r i n g c a r mode, and those near the low end of the income s c a l e f a v o u r i n g the bus ( F i g u r e 5) . BEHAVIOR PROFILES OF MODAL GROUPS  T r a v e l Time D i v e r s i o n curves of the r a t i o of t r a v e l time by t r a n s i t d i v i d e d by t r a v e l time by automobile have been documented f o r a number o f c i t i e s , and the curves i n d i c a t e a s t a b l e r e l a -t i o n s h i p between the t r a v e l time r a t i o and the p e r c e n t t r i p s d i v e r t e d to t r a n s i t f o r a s u b s t a n t i a l number o f c i t i e s . How-ever, mode used and a v a i l a b l e a l t e r n a t i v e s m o d i f i e s the i n f l u e n c e of time as a f a c t o r . * * * T h i s r a t e i s based on esti m a t e s of the Vancouver P l a n -ning Board on the b a s i s of s e l e c t e d zones. The study area r a t e i s f o r 1967 w h i l e t h a t f o r the m e t r o p o l i t a n r e g i o n i s f o r 1965. I t i s assumed t h a t these years are roughly e q u i v a l e n t . **Bock's study shows 41 pe r c e n t of c a r users w i t h r a i l -way a l t e r n a t i v e to c o n s i d e r time most important, w h i l e 6.9 per-c e n t p u b l i c t r a n s i t passengers w i t h a c a r a v a i l a b l e found time most important (see Ref. 9 ) . PERCENT I N EACH CATEGORY SHOWN 100 -90 -80 -70 -60 ~ 50 -40 -30 -20 -10 -0 -u <4000 CO CO CO < D < < P CJ PQ U CQ o m 1 4000 8000 - >12000 8000 12000 INCOME CATEGORY INCOME CATEGORY COMMUTERS BY CAR BY BUS < 4000 4000-8000 8000-12000 > 12000 99 402 540 511 325 487 265 86 FIGURE 5 INCOME CHARACTERISTICS OF COMMUTERS TO CBD, BY MODE USED 75. A b s o l u t e t r a v e l time i s not v a l u e d the same, r e l a t i v e to o t h e r f a c t o r s , by a l l groups. For. example Voorhees found t h a t workers o f h i g h income groups had an average t r i p d u r a t i o n g g r e a t e r than low income groups. T h i s c o u l d mean e i t h e r t h a t h i g h income groups have a h i g h e r p r o p e n s i t y to t r a v e l ( c u l t u r a l c o n d i t i o n i n g to auto use) or t h a t r e s i d e n t i a l - w o r k p l a c e r e l a -t i o n s h i p s are d i f f e r e n t from low income groups, or both. S p a t i a l s e p a r a t i o n of r e s i d e n c e from workplace f o r reasons o t h e r than t r a v e l i s probably the reason f o r l o n g e r t r i p dura-t i o n s i n c e , l o g i c a l l y , i f the v a l u e of time i s r e l a t e d to the wage r a t e we would expect h i g h incomes t o be a s s o c i a t e d w i t h l e s s time spent on the journey to work i f no o t h e r f a c t o r s are e f f e c t i v e . Mean r e p o r t e d o v e r a l l t r a v e l time f o r a l l case study c o r r i d o r commuters to the CBD i s 33.2 minutes. The mean f o r automobile users i s 30.9 minutes from t h e i r r e s i d e n c e l o c a t i o n to t h e i r d e s t i n a t i o n i n the CBD, and 3 6.8 minutes f o r bus passengers (Table V ) . The average t r a v e l time f o r a l l auto t r i p s i n Vancouver i s not a v a i l a b l e , but the c o r r i d o r mean of 3 0.9 minutes by c a r i s much g r e a t e r than the average f o r c i t i e s the s i z e of Vancouver. For i n s t a n c e Voorhees"^ found t h a t the average work t r i p d u r a t i o n by c a r f o r a c i t y o f about 1 m i l l i o n (Vancouver s i z e ) , based on an a n a l y s i s of 34 c i t i e s , i s about o n e - h a l f of the mean found i n t h i s case. The h i g h e s t average f o r a l l c i t i e s s t u d i e s was P h i l a d e l p h i a a t 20.1 minutes, i n d i -c a t i n g t h a t c o r r i d o r mean t r a v e l time by c a r i n Vancouver i s Table V TOTAL TRAVEL TIME, BY MODE* TRAVEL MODE TIME** CAR J BUS (MIN) No. o "O No. o. "5 1 0 29 ( 1 . 8 0 ) 63 ( 4 . 47 ) 1 5 56 ( 3 . 4 8 3 ( 0 . 25 ) 2 0 2 0 3 ( 1 2 . 6 3 ) 3 1 ( 2 . 62 ) 2 5 2 6 0 ( 1 6 . 1 8 ) 7 5 ( 6 . 3 3 ) 3 0 4 4 0 ( 2 7 . 3 8 ) 2 1 8 ( 1 8 . 40) 3 5 2 2 7 ( 1 4 . 1 3 ) 2 4 9 ( 2 1 . 01 ) 4 0 2 1 4 ( 1 3 . 3 2 2 4 3 ( 2 0 . 51 ) 4 5 . 1 3 4 ( 8 . 3 4 ) 1 7 0 ( 1 4 . 3 5 ) 50 34 ( 2 . 1 2 ) 1 0 2 ( 8 . 61 ) 5 5 10 ( 0 . 6 2 ) 4 1 ( 3 . 4 6 ) 1 , 6 0 7 ( 1 0 0 . 0 0 ) 1 , 1 8 5 ( 1 0 0 . 00 ) SIGNIFICANCE TEST : d i f f e r e n c e : of means * c = 3 0 . 9 *B = 3 6 . 8 s c = 8 . 97 S B = 1 2 . 33 z = - 1 3 . 0 0 p < . 0 0 1 *"How long i s your door-to-door journey i n minutes?" * * C e n t r a l v a l u e of 5 minutes i n t e r v a l s . u n u s u a l l y h i g h and probably r e p r e s e n t s the l o n g e s t average t r i p l e n g t h of any major t r a v e l c o r r i d o r w i t h both o r i g i n and des-t i n a t i o n i n the m e t r o p o l i t a n urban r e g i o n . T h i s phenomenon i s l a r g e l y because of c o n g e s t i o n on the B r i d g e d u r i n g peak p e r i o d s . S i g n i f i c a n c e t e s t s of the d i f f e r e n c e of means shows t h a t the o v e r a l l t r a v e l time f o r auto d r i v e r s i s s t a t i s t i c a l l y d i f f e r e n t than t h a t f o r bus passengers (Table V ) . The c o r r i d o r , w i t h r e a s o n a b l e s i m i l a r o v e r a l l mean t r a v e l times i s a unique c h a r a c t e r i s t i c of t h i s study area, and i n f e r e n c e s about t r a v e l times must be made on the b a s i s t h a t w h i l e auto d r i v i n g times are h i g h , bus times are r e a s o n a b l e when compared w i t h other c i t i e s , and may be a f a c t o r i n the h i g h p r o p o r t i o n of p r o f e s s i o n a l o c c u p a t i o n a l s t a t u s who r i d e the bus and who are time s e n s i t i v e . On the o t h e r hand, the p r o p o r t i o n of bus passengers to auto d r i v e r s i n the commuter stream i s not u n u s u a l l y h i g h , i n d i -c a t i n g t h a t time savings by bus may not be v a l u e d p a r t i c u l a r l y i mportant by a l l commuters. When o v e r a l l t r a v e l time i s r e l a t e d to socioeconomic group as w e l l as to mode used, a d i f f e r e n t and s i g n i f i c a n t , p a t t e r n emerges. -. The v a r i a t i o n by income c l a s s i n the t r a v e l time to work i s s u b s t a n t i a l (Table V I ) . In a l l income c l a s s e s the bus i s slower. Car t r a v e l time i n c r e a s e d w i t h i n c r e a s i n g income as expected, but by bus, the t r a v e l time decreases w i t h income 7 8 . T a b l e VI MEAN TOTAL TRAVEL TIME, BY INCOME CATEGORY AND MODE INCOME MEAN TRAVEL TIME CATEGORY BY CAR BY BUS OVERALL < 4 0 0 0 2 5 . 4 4 1 . 0 3 7 . 3 4 0 0 0 - 8 0 0 0 30 . 8 3 7 . 5 3 4 . 6 8 0 0 0 - 1 2 0 0 0 3 0 . 8 3 6 . 4 3 2 . 5 > 1 2 0 0 0 3 2 . 3 3 8 . 0 33 . . 2 X c = 31 . 0 * *B = 3 8 . 3 * X n = 3 4 . 1 * SIGNIFICANCE TEST : V a r i a n c e R a t i o * * SOURCE OF D.F. SUM OF MEAN F p VARIATION SQUARES SQUARE MODE 1 54 . 5 0 5 4 . 5 0 2 . 3 2 n.s INCOME 3 5 5 . 4 4 1 8 . 5 0 0 . 7 9 n. s ERROR 3 70 . 4 4 2 3 . 5 0 TOTAL 7 1 8 0 . 3 8 * O v e r a l l means of each category d i f f e r from t o t a l sample as r e p o r t e d on Table V because of the d i f f e r e n t response f r e q u e n c i e s by each s o c i o -economic group. 2 * * V a r i a n c e R a t i o F, i s the estimate of S based on the v a r i a t i o n i n t r a v e l time by mode -f the estimate of s 2 based on the v a r i a t i o n i n income. up t o the $ 1 2 , 0 0 0 income c l a s s . The percentage p o i n t s s e p a r a t i the mean t r a v e l times of c a r users and bus passengers decrease w i t h i n c r e a s i n g incomes, although $ 1 2 , 0 0 0 income c l a s s again d e v i a t e s from t h i s t r e n d . I t appears t h a t those of low income who have a c a r a v a i l a b l e f o r the work journey have the l e a s t t r a v e l time to work. T h i s may be a r e s u l t of s e v e r a l f a c t o r s : (1 ) these are i n d u s t r i a l workers and s t a r t work a t e a r l y morning hours, thereby a v o i d i n g the main t r a f f i c peak, (2 ) they may be young, unmarried persons who have j u s t e n t e r e d the l a b o u r f o r c e and l i v i n g communally i n the h i g h r i s e s of West Vanc o u v e r . c l o s e to t h e i r work. I t i s i n the low.income category where the s t r i k i n g d i f f e r e n c e i s seen between those who are c a p t i v e t o buses and have a very long journey time, and those who have a c h o i c e . T h i s r e p r e s e n t s the major d i f f e r e n c e i n s e r v i c e l e v e l s between bus and c a r modes. Abs o l u t e t r a v e l times by a l l modes decrease w i t h i n -come up t o the $ 1 2 , 0 0 0 group. The v a r i a t i o n w i t h i n income groups i n t h e i r o v e r a l l t r a v e l time i s g r e a t enough to l a r g e l y e l i m i n a t e t r a v e l time as a f a c t o r i n mode c h o i c e (Table V I ) . V a r i a n c e r a t i o s , or F v a l u e s , are s m a l l both f o r the d i f f e r e n c e between modal t r a v e l times and f o r the d i f f e r e n c e s i n t r a v e l times w i t h i n the income groups. T h i s i n d i c a t e s t h a t when the v a r i a t i o n between income groups i s c o n s i d e r e d , t r a v e l time i s not a s i g n i -f i c a n t f a c t o r i n the d i f f e r e n c e s between modes. Although the v a r i a t i o n between modal t r a v e l times i s g r e a t , t h a t between income groups i s a l s o l a r g e enough to reduce the e f f e c t of mode time. I t a l s o means t h a t mode c h o i c e , as i t i s dependent upon t r a v e l time, does not vary s i g n i f i c a n t l y between d i f f e r e n t income groups, a c o n c l u s i o n which i s supported as w e l l by Zupan who found t h a t income s t r a t i f i c a t i o n would o n l y improve mode 80 . s p l i t p r e d i c t i o n i f incomes changed very radically."'""'" Our i n f e r e n c e i s t h a t w h i l e r e a l d i f f e r e n c e s appear to e x i s t i n the t r a v e l times of the two modes, when incomes are c o n s i d e r e d what appears to be s u b s t a n t i a l d i f f e r e n c e s i n modal times are i n f a c t due mainly to d i f f e r e n c e s i n the t r a v e l times of d i f -f e r e n t income groups. A d i f f e r e n t c o n c l u s i o n comes from an a n a l y s i s of o c c u p a t i o n groups and mode s p l i t (Table V I I ) . L i k e income, a l l t r a v e l times by bus are g r e a t e r , but h i g h s t a t u s o c c u p a t i o n s are not a s s o c i a t e d w i t h the l o n g e s t t r i p l e n g t h s . By c a r , s e c r e -t a r i e s have the g r e a t e s t t r i p l e n g t h , f o l l o w e d by s a l e s persons and managers. By bus, c l e r i c a l workers f o l l o w e d by " o t h e r " (craftsmen, l a b o u r e r s ) , are l o n g e s t . S e c r e t a r i e s and managers have the next l o n g e s t t r i p l e n g t h s . P r o f e s s i o n a l employees have the s h o r t e s t t r a v e l d u r a t i o n i n t h e i r r e s p e c t i v e modes, and the lowest of a l l groups r e g a r d l e s s of mode; although t r i p l e n g t h s f o r p r o f e s s i o n a l s t r a v e l l i n g by bus i s s u b s t a n t i a l l y g r e a t e r than those by c a r . These r e s u l t s i n d i c a t e t h a t , a l -though o c c u p a t i o n and incomes may be c o r r e l a t e d , t h e r e i s an independent dimension of o c c u p a t i o n a l c a t e g o r y which i s impor-t a n t f o r mode c h o i c e . I t appears to suggest t h a t although p r o f e s s i o n a l employees may be i n h i g h e r income c a t e g o r i e s they are more time s e n s i t i v e than the h i g h e r income group as a whole, and t h e r e f o r e may a l s o have d i f f e r e n t mode c h o i c e h a b i t s and r e s i d e n c e - w o r k p l a c e r e l a t i o n s h i p s . 81. Tab l e VII MEAN TOTAL TRAVEL TIME, BY OCCUPATIONAL CATEGORY AND MODE OCCUPATIONAL CATEGORY MEAN TRAVEL TIME BY CAR BY BUS OVERALL MANAGERIAL 31.5 37.5 33.0 PROFESSIONAL 27.8 36.7 31.3 SECRETARIAL. 34.0 37.5 36.8 CLERICAL 29.7 28.3 32.0 SALES 31.5 36.9 34.0 OTHER 28.6 37.8 31.7 X = 31.5 X = 36.8 X = 33.8 SIGNIFICANCE TEST: V a r i a n c e R a t i o SOURCE OF D.F. SUM OF MEAN F p VARIATION SQUARES SQUARE MODE 1 28, .58 28. .58 15. ,00 < .05 OCCUPATION 5 141. .50 28. .25 14. ,90 < .05 ERROR 5 9, .53 1. .90 TOTAL 11 179 . .61 V a r i a n c e r a t i o s as shown on Table V II f o r mode use and o c c u p a t i o n a l c l a s s on t r a v e l time i n d i c a t e t h a t t h e r e i s a s i g n i f i c a n t d i f f e r e n c e i n the t r a v e l times w i t h i n each occupa-t i o n a l group between those of t h a t c l a s s who use c a r and those who use bus. There i s a l s o a s i g n i f i c a n t d i f f e r e n c e i n each o c c u p a t i o n a l group's t r a v e l time to work, r e g a r d l e s s of mode used. T h i s would i n d i c a t e t h a t t r a v e l time a t t r i b u t e s f o r a 82. t r a n s p o r t a t i o n system are v a l u e d d i f f e r e n t l y by d i f f e r e n t occu-p a t i o n groups. P e r c e i v e d T r a v e l Time T r a v e l time i s u s u a l l y t h a t which i s the d i f f e r e n c e between the average zone to zone t r a v e l time by each mode as measured by an over the road d i s t a n c e proxy, or a c t u a l t r a v e l time as measured i n the f i e l d . Some r e c e n t surveys have measured p e r c e i v e d t r a v e l time, and a m o d i f i c a t i o n of t h i s , the time of depa r t u r e and a r r i v a l , but onl y one or two surveys have been made of the p e r c e i v e d r e l a t i v e t r a v e l times; ( i . e . the p e r -c e i v e d t r a v e l time of the mode used as w e l l as t h a t of i t s a l -t e r n a t i v e ) . Measures of the p e r c e i v e d t r a v e l time by the a l t e r n a t i v e mode f o r North Shore commuters are shown i n Table V I I I . Two f a c t s emerge from t h i s t a b l e ; (1) r e l a t i v e l y few auto d r i v e r s r e p o r t t h a t the bus i s f a s t e r w h i l e s t i l l t a k i n g the car (10.26 percent) c o n t r a s t e d w i t h c l o s e to 30 p e r c e n t (29.13) of bus r i d e r s who r e p o r t the c a r i s f a s t e r , and (2) the g r e a t number of auto d r i v e r s r e p o r t i n g t h a t they do not know the t r a v e l time of the bus. These f i n d i n g s are c o n s i s t e n t w i t h what i s known about mode c h o i c e . The g r e a t e r numbers of bus r i d e r s who r e p o r t the c a r f a s t e r i n c l u d e s c a p t i v e s . I t i s prob-able t h a t bus r i d e r s know rea s o n a b l y w e l l the t r a v e l time by auto. However, i t i s obvious t h a t many c a r d r i v e r s do not know the t r a v e l time by bus. In f a c t 57.2 p e r c e n t of a l l c a r d r i v e r s r e p o r t e d t h a t they never t r a v e l by bus and another 3 6.8 p e r c e n t 8 3 . T a b l e V I I I RELATIVE TRAVEL TIME 3Y BUS COMPARED TO THAT BY CAR FOR CAR AND BUS ALTERNATIVE* TRAVEL TIMES BY PERCEIVED TRAVEL TIME OF ALTERNATE BUS COMPARED TO FOR CAR USERS FOR BUS USERS THAT BY CAR NUMBER % NUMBER % > 1 5 Min 2 3 ( 1 . 4 3 ) 5 5 ( 4 . 6 4 ) BUS 1 1 - 1 5 2 9 ( 1 . 8 0 ) 1 0 9 ( 9 . 2 0 ) FASTER 6 - 1 0 6 5 ( 4 . 0 5 ) 1 1 8 ( 9 . 9 6 ) BY 1 - 5 4 8 ( 2 . 9 8 ) 6 3 ( 5 . 3 2 ) 0 1 4 9 ( 9 . 2 7 ) 9 2 ( 7 . 7 6 ) BUS 1 - 5 M i n 5 7 ( 3 . 5 6 ) 4 7 ( 3 . 9 7 ) SLOWER 6 - 1 0 1 7 2 ( 1 0 . 7 0 ) 1 2 1 ( 1 0 . 2 1 ) BY 1 1 - 1 5 4 2 7 ( 2 6 . 6 0 ) 1 4 7 ( 1 2 . 4 1 ) > 1 5 na** 1 5 6 ( 1 3 . 1 6 ) D . K 5 1 3 ( 3 1 . 9 0 ) 2 7 7 ( 2 3 . 3 8 ) N.R 1 2 4 ( 7 . 7 1 ) TOTAL 1 , 6 0 7 ( 1 0 0 . 0 0 ) 1 , 1 8 5 ( 1 0 0 . 0 0 ) *"How does t h e d o o r - t o - d o o r j o u r n e y by bus compare t o t h a t by c a r ? " **Not i n c l u d e d i n t h e s u r v e y . s a i d they d i d o n l y o c c a s i o n a l l y . T h e r e f o r e , i t i s r e a s o n a b l e t o c o n c l u d e t h a t a l a r g e p r o p o r t i o n o f c a r d r i v e r s a r e n o t aware o f t h e bus t i m e s , and would have a low p r o p e n s i t y t o use t r a n s i t , even i f t r a v e l t ime was d e c r e a s e d s u b s t a n t i a l l y . As one would e x p e c t , t h e p r o p o r t i o n o f t h o s e commuting by c a r who s a i d t hey d i d n o t know t h e ti m e by bus went up w i t h i n c r e a s i n g income l e v e l s . F o r t h e under $ 4 , 0 0 0 group o n l y 7 . 5 p e r c e n t s a i d t h e y d i d n o t know bus t r a v e l t i m e , whereas o f t h o s e o v e r $ 1 2 , 0 0 0 4 6 . 4 p e r c e n t s a i d t hey d i d n o t know. L i k e w i s e , 8 4 . o c c u p a t i o n a l s t a t u s determined p e r c e p t i o n o f the bus a l t e r -n a t i v e w i t h 3 8 . 0 p e r c e n t of p r o f e s s i o n a l s and 3 9 . 8 p e r c e n t o f the managers i n the "don't know" cate g o r y , whereas on l y 1 3 . 3 p e r c e n t s e c r e t a r i e s and 1 9 . 2 p e r c e n t c l e r k s were i n t h i s c a t e -gory. Salesmen who drove r e p o r t e d 5 6 . 2 p e r c e n t "don't know." R e l a t i v e O v e r a l l T r a v e l Cost A s u b s t a n t i a l concern has been g i v e n t o c o s t as a f a c t o r i n mode c h o i c e because of the consuming i n t e r e s t i n c o s t and p r i c e f u n c t i o n s f o r t r a n s p o r t a t i o n p r o j e c t e v a l u a t i o n and economic investment i n the commodity s e c t o r . The same emphasis has permeated the passenger t r a n s p o r t a t i o n aspect of t r a n s p o r -t a t i o n p l a n n i n g and t h e r e f o r e much e f f o r t has been extended on r e l a t i o n s between mode c h o i c e and the p r i c e (cost) of t r a v e l . I t i s c l e a r t h a t c o s t i s a f a c t o r where the t o t a l market (cap-t i v e and choice) i s c o n s i d e r e d . I t i s not c l e a r what e f f e c t c o s t has on o n l y c h o i c e r i d e r s . The l e v e l of t r a n s i t f a r e s may have some e f f e c t on r i d e r s h i p a l t h o u g h the e f f e c t s o f f a r e s a re not c o n c l u s i v e from the l i t e r a t u r e . The c o n s u l t a n t s f o r the S e a t t l e P u b l i c T r a n s p o r t a t i o n P l a n s t a t e : " f a r e l e v e l , u n l e s s i t was substan-t i a l l y d i f f e r e n t from the p r e s e n t , would not have s i g n i f i c a n t 12 e f f e c t . " The M e t r o p o l i t a n Toronto T r a n s p o r t a t i o n P l a n u s i n g the model c i t e d above, i n c l u d e d a s e r i e s of t e s t s of v a r i o u s s e r v i c e l e v e l changes on v e h i c l e and t r a n s i t usage. Doubling t r a n s i t f a r e s .increased auto t r i p s by about on l y 3 p e r c e n t 8 5 . 13 and decreased t r a n s i t use by about 4 p e r c e n t . I f t r a n s i t f a r e s were reduced by 50 p e r c e n t v e h i c l e t r i p s would decrease 5 p e r c e n t and t r a n s i t t r i p s i n c r e a s e about 7 p e r c e n t . With no t r a n s i t f a r e ( i . e . f r e e t r a n s i t ) , v e h i c l e use would drop about 8 p e r c e n t w i t h an 11 p e r c e n t i n c r e a s e i n t r a n s i t r i d e r s h i p . These appear to be modest changes i n mode s p l i t i n c o n s i d e r i n g some of the more d r a s t i c changes i n f a r e s t r u c t u r e . A se a r c h of the ex p e r i m e n t a l s t u d i e s c a r r i e d out i n c o n j u n c t i o n w i t h the Demonstration Grants Program i n the U.S. r e v e a l e d o n l y f r a g -mentary r e s u l t s . The success of the Minibus experiment i n 14 Washington D.C. i s a t l e a s t p a r t l y a t t r i b u t e d to i t s 5C f a r e , but patrons are shoppers and s i m i l a r r e s u l t s may not be achieved f o r commuters. I t thus appears t h a t f a r e changes e i t h e r upward or downward are expected to have o n l y modest e f f e c t s on mode s p l i t p l a n n i n g . The c o n s i d e r a t i o n of v e h i c l e o p e r a t i o n c o s t s ( o i l , gas, d e p r e c i a t i o n etc.) i s a d i f f i c u l t problem i n mode c h o i c e r e s e a r c h . Those t h a t have used t h i s v a r i a b l e have i n v a r i a b l y imputed c o s t s from some average c o s t per m i l e m u l t i p l i e d by the t r i p d i s t a n c e i n m i l e s . T h i s i s used as an " o b j e c t i v e " measure of v e h i c l e o p e r a t i n g c o s t and has very l i t t l e r e l e v a n c e f o r mode c h o i c e because of two major d i f f i c u l t i e s ; (1) over the road d i s t a n c e s used may have very l i t t l e r e l a t i o n s h i p to a c t u a l over the road c o s t s s i n c e running speed i s seldom measured over t h i s d i s t a n c e (because c o s t v a r i e s w i t h running speed, grades e t c . , s t r a i g h t d i s t a n c e measures u s i n g assumed or average 8 6 . running speeds, and the use of average c o s t s per m i l e may be s u b j e c t to l a r g e e r r o r s ) , (2) the e n g i n e e r i n g measures of v e h i c l e c o s t s . There i s some evidence to support the c o n c l u -s i o n t h a t a g r e a t p r o p o r t i o n of t r a v e l l e r s do not p e r c e i v e what i t c o s t s to use t h e i r c a r f o r a g i v e n t r i p t o work. T h i s has l e a d Quarmby to the c o n c l u s i o n t h a t i t may w e l l be "hazardous" to use " e n g i n e e r i n g " c o s t s to t r y to e x p l a i n 15 b e h a v i o r . I f people do not p e r c e i v e the amount of the c o s t of o p e r a t i n g t h e i r v e h i c l e the q u e s t i o n i s do they p e r c e i v e t h a t t h e r e i s some c o s t . T h i s i s t i e d i n w i t h auto ownership. I f a c a r i s p e r c e i v e d to be p r i m a r i l y a s o c i a l good and, once purchased, used f o r work purposes i t i s c o n c e i v a b l e t h a t the c o s t of the journey to work i s not c o n s i d e r e d a t a l l i n the mode c h o i c e d e c i s i o n . I f the c a r i s purchased s o l e l y f o r com-muting the c o s t of o p e r a t i n g i t on the commuting t r i p i s prob-a b l y p a r t of the mode c h o i c e d e c i s i o n , although i f i t i s a second c a r comfort and convenience f a c t o r s may p l a y a g r e a t e r r o l e than c o s t . That i s , the c a r i s purchased f o r commuting because t r a n s i t s e r v i c e i s not a c c e p t a b l e . Presumably ca r purchase and use i s a complex d e c i s i o n with both motives being p r e s e n t , but the author b e l i e v e s t h a t most auto purchase d e c i -s i o n s tend toward t h a t f o r a s o c i a l good and a l l round use, w i t h l i t t l e thought g i v e n to the c o s t of a s i n g l e journey to work. For these reasons, and because o f data l i m i t a t i o n s on i n d i v i d u a l d i s t a n c e measures and on average per m i l e v e h i c l e 87 . c o s t s t h i s i n v e s t i g a t i o n uses o u t - o f - p o c k e t expenses as the s o l e measure of c o s t f a c t o r s . These are the c o s t s i n c u r r e d a t the time of use; t r a n s i t f a r e s and p a r k i n g c o s t s , and t h e r e f o r e serve to p r e s e r v e the l o g i c a l nature o f the mode ch o i c e d e c i s i o n c o i n c i d e n t with the p e r c e i v e d measures of modal a t t r i b u t e s used throughout t h i s i n v e s t i g a t i o n . V e h i c l e c o s t s , p a r k i n g c o s t s , t o l l s , and t r a n s i t f a r e s are onl y meaningful i n the mode c h o i c e d e c i s i o n i f r e -l a t e d to the a b i l i t y to pay ( i . e . to income l e v e l s ) . Quarmby summarizes t h i s r e l a t i o n s h i p : From the axiom t h a t h i g h e r income t r a v e l l e r s are b e t t e r a b l e to a f f o r d to pay a premium to s a t i s f y t h e i r p r e f e r e n c e s than are low income t r a v e l l e r s , i t f o l l o w s t h a t i f the c o s t of t r a v e l l i n g by c a r i s g r e a t e r than by p u b l i c t r a n s p o r t the e f f e c t of h i g h e r income i s to l e s s e n the e f f e c t of c o s t as a d e t e r r e n t t o u s i n g car.16 I f r e l a t i v e c o s t s o f the modes i s very d i f f e r e n t the e f f e c t o f c o s t w i l l depend upon income; i f c o s t s are n e a r l y equal the e f f e c t o f c o s t w i l l p r obably become i n s i g n i f i c a n t . Quarmby argues t h e r e f o r e t h a t c o s t s s h o u l d always be expressed as a f u n c t i o n o f income. The out of pocket expenses used i n t h i s study i n c l u d e t r a n s i t f a r e s and p a r k i n g c o s t s . The commuted t r a n s i t f a r e f o r B.C. Hydro Bus s e r v i c e s e r v i n g v i r t u a l l y a l l the area e a s t of the B r i d g e i s 3 5 cents per t r i p ' to the CBD. West Vancouver buses had v a r i a b l e d i s t a n c e f a r e s i n 1967 w i t h the h i g h e s t 88 . commuted f a r e from the most d i s t a n t p o i n t a t 54 cents and the lowest a t the Bridge-head of 20 c e n t s . T a b l e IX ' PARKING CHARGE AT CBD DESTINATION* MONTHLY No. % DAILY No. CHARGE CHARGE FREE 368 (30 .34) FREE 44 (24 .31) 0-10 .00 250 (20 .61) 0- . 50 15 ( 8 .29) 10.01-20 .00 472 (39 .91) .51-1. 00 . 74 (40 .88) 20.01-30 .00 119 ( 9 .81) 1.01-1. 50 37 (20 .44) 30.01-40 .00 3 ( o .25) 1.51-2. 00 6 ( 3 .31) >40 .00 1 ( o .08) >2. 00 1 ( o .55) N.R 4 ( 2 .21) TOTAL 1213 (100 .00) 181 (100 .00) *"What do you now pay f o r p a r k i n g ? " P a r k i n g charges are shown i n Table IX. A s t r i k i n g f a c t i s t h a t over 30 p e r c e n t of monthly p a r k e r s have no p a r k i n g charge, and a h i g h percentage of d a i l y p a r k e r s as w e l l . P r e -sumably these people have p a r k i n g space p r o v i d e d by t h e i r employers. I f we assume t h a t v e h i c l e o p e r a t i n g c o s t i s not a p e r c e i v e d c o s t of the work t r i p and w i t h f r e e p a r k i n g (again p e r c e i v e d f r e e s i n c e i t may be p a i d f o r as p a r t of the wage s t r u c t u r e of the firm) f u l l y 30 p e r c e n t of the auto d r i v i n g workers to the CBD have no p e r c e i v e d c o s t s . Another 20.6 per-cent pay l e s s than $10 w h i l e c l o s e to 90 p e r c e n t of a l l p a r k e r s pay l e s s than $20 per month. Somewhat l e s s people, who pay d a i l y r a t e s are i n the same c o s t e q u i v a l e n t s i t u a t i o n w i t h 89. 73.5 p e r c e n t paying l e s s than $1.00 per day.* T h i s g e n e r a l l y low p a r k i n g charge has g r e a t i m p l i c a t i o n s f o r mode c h o i c e . I t was expected t h a t p a r k i n g r a t e s may be r e l a t e d to income c a t e g o r y w i t h those of h i g h e r incomes paying g r e a t e r p a r k i n g fees (Table X ) . No p a t t e r n i s c o n c l u s i v e however w i t h p a r k i n g charges by income much the same as the t o t a l sample. There i s some tendency f o r very low income workers to pay very h i g h p a r k i n g r a t e s . T h i s may be due to the i n a b i l i t y o f t h i s group to b a r g a i n f o r p a r k i n g as p a r t of the f r i n g e b e n e f i t s of t h e i r j o b . Table X PARKING CHARGE BY INCOME CATEGORY** INCOME FREE <10 10-20 >20 CATEGORY No. % No. % No. % No. % <4000 13 (28.9) 8 (17.8) 21 (46.6) 3 ( 6.7) (100.0) 4000-8000 107 (33.0) 84 (25.8) 116 (35.6) 18 ( 5.6) (100.0) 8000-12000 151 (31.4) 96 (20.0) 175 (36.4) 59 (12.2) (100.0) >12000 123 (31.5) 70 (14.6) 219 (45.6) 78 (16.2) (100.0) **"What do you now pay f o r p a r k i n g ? " P a r k i n g charge by o c c u p a t i o n i s shown i n Tab l e XI. Again i n most cases, the p a r k i n g charge f o r each group i s c l o s e to the average, w i t h the e x c e p t i o n of i n d u s t r i a l workers who appear to have a hi g h p r o p o r t i o n of f r e e p a r k i n g . T h i s probably •Assuming 20.8 working days per month l e s s 10 s t a t u -t o r y h o l i d a y s the monthly and d a i l y r a t e s become e q u i v a l e n t . 9 0 . T a b l e IX PARKING CHARGE BY OCCUPATION CATEGORY* OCCUPATION CATEGORY FREE 10 10 - 2 0 20 No. a *o No . o, *o No. g, o No. Q. "O MANAGERIAL 1 2 2 ( 2 9 . 3) 8 1 ( 2 0 . 2) 1 5 0 ( 3 6 . 0 ) 61 ( 1 4 . 6) ( 1 0 0 • 0) PROFESSIONAL 164 ( 3 0 . 2) 9 1 ( 1 6 . 8) 2 2 5 ( 4 1 . 4 ) 64 ( 1 1 . 8) ( 1 0 0 . 0 ) SECRETARIAL 9 ( 2 1 . 4) 13 ( 3 1 . 0) 20 ( 4 7 . 6 ) 0 ( o . 0) ( 1 0 0 . 0 ) CLERICAL 26 ( 2 9 . 6) 26 ( 2 9 . 6) 3 3 ( 3 7 . 5 ) 3 ( 3 . 3) ( 1 0 0 . 0 ) SALES 46 ( 2 4 . 2) 31 ( 1 6 . 3) 85 (44 . 7 ) 28 ( 1 4 . 8) ( 1 0 0 . 0 ) OTHER 34 ( 4 5 . 5) 1 5 ( 2 0 . 0) 22 ( 2 9 . 3 ) 4 ( 5 . 3) ( 1 0 0 . 0 ) *"What do you now pay f o r p a r k i n g ? " r e f l e c t s the p e r i p h e r a l l o c a t i o n o f the work p l a c e s of these employees with f r e e or i n e x p e n s i v e p a r k i n g a v a i l a b l e a t t h e i r i n d u s t r i a l p l a n t s . Convenience Convenience c o n s t i t u t e s t i m e - d i s t a n c e f a c t o r s which are i n c u r r e d o u t s i d e the v e h i c l e and i n c l u d e excess t r a v e l times or t e r m i n a l times. Excess t r a v e l time i s d e f i n e d as t h a t p o r t i o n of t r a v e l time which i s n o n - v e h i c u l a r ; w a l k i n g and w a i t i n g times. I t i s g e n e r a l l y f e l t t h a t s a v i n g s i n these times are more impor-t a n t t o the user than i n - v e h i c l e times. I t i s r e c o g n i z e d t h a t non-running times have more i n f l u e n c e on t r a v e l b e h a v i o r than running time, because of the p s y c h o l o g i c a l e f f e c t of w a i t i n g , t r a n s f e r r i n g , and the d i s c o m f o r t s of w a l k i n g . The weight g i v e n 17 i s u s u a l l y taken to be about 2.5 of running time. 9 1 . Table XII TERMINAL TIME AT ORIGIN BY MODE CAR MODE* BUS MODE* MINUTES No. % No. % 0 1 1 0 7 ( 6 8 . 8 9 ) 36 ( 3 . 0 4 ) 1 - 3 3 8 5 ( 2 3 . 9 6 ) 5 0 4 ( 4 2 . 5 3 ) 3 - 5 18 ( 1 . 1 2 ) 3 7 7 ( 3 1 . 8 1 ) 5 - 1 0 1 1 ( 0 . 6 8 ) 1 8 6 ( 1 5 . 7 0 ) 10 or + 3 9 ( 2 . 4 3 ) 79 ( 6 . 6 7 ) N.R 47 ( 2 . 4 2 ) 3 ( 0 . 2 5 ) TOTAL 1 6 0 7 . ( 1 0 0 . 0 0 ) 1 1 8 5 ( 1 0 0 . 0 0 ) *"How lo n g does i t take you to t r a v e l : from the s t a r t of your journey to your c a r (to the bus s t o p ) ? " Table XII shows t h a t f u l l y 9 2 . 9 p e r c e n t of auto u s e r s are w i t h i n 3 minutes of the v e h i c l e a t the r e s i d e n t i a l end of the t r i p , w h i l e o n l y 4 5 . 6 p e r c e n t of bus passengers are w i t h i n t h i s l i m i t . Although no d e f i n i t i v e standards e x i s t the 5 4 . 4 p e r c e n t of bus passengers who walk more than 3 minutes probably f e e l c o n s t r a i n e d to use t r a n s i t i f a car i s a v a i l a b l e . There are no accepted t o l e r a n c e s on how f a r people w i l l walk t o use t r a n s i t i f a c a r i s t h e o r e t i c a l l y a v a i l a b l e . L a n s i n g and Hendricks found f o r example t h a t auto users d i d not c o n s i d e r t h a t they had a c h o i c e o f mode un l e s s they were c l o s e r to t r a n -s i t s e r v i c e than the average d i s t a n c e a c t u a l l y walked by t r a n s i t 18 r i d e r s . By a r b i t r a r i l y u s i n g a 1 0 minute d i s t a n c e as the d e f i n i t i o n of t r a n s i t a v a i l a b i l i t y they were a b l e t o i n c r e a s e those who s a i d they had a c h o i c e from 26 p e r c e n t under the p e r c e i v e d a v a i l a b i l i t y ( l e s s than t r a n s i t walkers) to 44 p e r c e n t at the 10 minute s e r v i c e a r ea. I f the p e r c e p t i o n of whether or not t r a n s i t i s a v a i l a b l e i s taken as the c u t - o f f f o r the t o l e r a b l e d i s t a n c e to t r a n s i t , i t i s c l e a r from L a n s i n g and Hendrick's work t h a t a g r e a t number of respondents would con-s i d e r t h a t a c h o i c e i s a v a i l a b l e o n l y i f t h i s d i s t a n c e i s somewhat l e s s than 10 minutes. R e l a t i v e l y few respondents r e p o r t e d a t r a n s f e r (22 percent) and l e s s than 12 p e r c e n t r e p o r t e d an a c t u a l time i n -v o l v e d i n making the t r a n s f e r (Table XIII) . Of those who ex-p e r i e n c e d t r a n s f e r time only a very s m a l l p r o p o r t i o n s a i d i t was more than 5 minutes. I t i s c o n c e i v a b l e t h a t t r a n s f e r time i s not important to the mode c h o i c e d e c i s i o n , but t h a t the mere i n t e r r u p t i o n of the journey i s the o p e r a t i v e f a c t o r i . e . comfort. No study i s a v a i l a b l e on t h i s , but i t has been found t h a t an analogous s i t u a t i o n , v e h i c l e s i n t e r r u p t i o n by t r a f f i c 19 s i g n a l s has some e f f e c t s on r o u t e c h o i c e . For those who used bus, 83.0 p e r c e n t waited l e s s than 5 minutes a t the bus s t o p . S i n c e the bus frequency i s r e l a -t i v e l y low f o r most p a r t s of the North Shore, these r e l a t i v e l y s m a l l w a i t i n g p e r i o d s i n f e r t h a t most r i d e r s have s t r e a m l i n e d t h e i r journey by knowing schedules and l o c a l bus c o n d i t i o n s . The d i s t r i b u t i o n time a t the CBD d e s t i n a t i o n may be p a r t i c u l a r l y c r i t i c a l to mode s p l i t . P a r k i n g time, unparking Table XIII OUT-OF-VEHICLE TIMES FOR BUS PASSENGERS MINUTES TRANSFER TIME* WAITING TIME* No . Q. O No . a "6 0 123 (10.38) 35 ( 2.95) 1-3 59 ( 4.98) 383 (32.32) 3-5 49 ( 4.14) 566 (47.76) 5-10 22 ( 1.86) 168 (14.18) 10 or + 8 ( 0.68) 19 ( 1.60) N.R 924 (77.97) 14 ( 1.18) TOTAL 1185 (100.00) 1185) (100.00 *"How long does i t take you t o - w a i t a t t r a n s f e r p o i n t (wait f o r bus)?" time, the walk from t r a n s i t v e h i c l e or p a r k i n g l o t to f i n a l d e s t i n a t i o n are f a c t o r s c o n s i d e r e d important f o r mode c h o i c e . T a b l e XIV shows the d i s t r i b u t i o n of walk times f o r those who a r r i v e a t t h e i r d e s t i n a t i o n by automobile and f o r those who a r r i v e by bus. The auto walk t r i p l e n g t h d i s t r i b u t i o i s bimodal i n d i c a t i n g t h a t a dichotomous s i t u a t i o n p r e v a i l s . I t i s h y p o t h e s i z e d t h a t those who park c l o s e t o t h e i r work l o c a t i o n e i t h e r have f r e e p a r k i n g or pay h i g h r a t e s , and t h a t another group e x i s t s which cannot a f f o r d the h i g h r a t e s assoc-i a t e d with c l o s e - i n p a r k i n g and t h e r e f o r e must f i n d a s u i t a b l e t r a d e - o f f between p a r k i n g c o s t , and walking d i s t a n c e . These park a t g r e a t e r d i s t a n c e s , and form a d e f i n i t e secondary group. About 58 p e r c e n t of a l l workers park w i t h i n 5 minutes of t h e i r Table XIV TERMINAL TIME AT DESTINATION BY MODE* MINUTES BY CAR BY BUS No. Q, "o No . o, "O 0 272 (16. 93) 12 ( 1.01) 1-3 431 (26. 82) 302 (25.49) 3-5 228 (14. 19) 436 (36.79) 5-10 125 ( 7. 78) 253 (21.35) 10 or + 512 (31. 86) 21 ( 1.77) TOTAL 1607 (100. 00) 1185 (100.00) *"How long does i t take you to t r a v e l : from your c a r (the bus) to end of journey?" f i n a l d e s t i n a t i o n whereas about 40 p e r c e n t park more than 5 minutes away and 32 p e r c e n t are 10 minutes o r more away. Use-f u l c r i t e r i a f o r subway s t a t i o n s e r v i c e areas are a 5 minute walk a t 300 f t . per min. or s t r a i g h t l i n e d i s t a n c e of 1500 f e e t . Using t h i s s tandard f o r automobile users i n d i c a t e s t h a t a l a r g e p r o p o r t i o n are inconvenienced, but o b v i o u s l y not enough to s w i t c h to the bus. Indeed bus s e r v i c e i s such t h a t almost 35 p e r c e n t of bus users walk more than 5 minutes t o t h e i r des-t i n a t i o n . T h i s means t h a t c e r t a i n groups w i l l t o l e r a t e sub-s t a n t i a l w a lking d i s t a n c e s a t the d e s t i n a t i o n b e f o r e s w i t c h i n g mode. Table XV shows the percentage of each income group walking l e s s than 5 minutes and those more than 5 minutes. There i s a d e f i n i t e tendency to park c l o s e r to f i n a l d e s t i n a -t i o n as income i n c r e a s e s . The s i g n i f i c a n c e t e s t u s i n g the Table XV PERCENTAGE OF THOSE GOING BY CAR IN EACH WALKING DISTANCE CATEGORY FROM PARKING LOT TO FINAL DESTINATION, BY INCOME AND OCCUPATION WALKING DISTANCE LESS THAN MORE THAN 5 MINUTES 5 MINUTES INCOME CATEGORY: <4000 54.3 45.7 (100.0) 4000-8000 55.0 45.0 (100.0) 8000-12000 60.0 40.0 (100.0) >12000 62.5 37.5 (100.0) SIGNIFICANCE TEST: Chi-square X 2 = 8.12 D.F. = 3 • p < .05 OCCUPATION CATEGORY: MANAGERIAL 59.0 41.0 (100.0) PROFESSIONAL 62.6 37.5 (100.0) SECRETARIAL 44.3 55.7 (100.0) CLERICAL 55.6 44.7 (100.0) SALES 53.7 46.3 (100.0) OTHER 71.6 28.4 (100.0) SIGNIFICANCE TEST: Chi-square X 2 = 21.22 d . f . = 5 p < .001 c h i - s q u a r e s t a t i s t i c shows t h a t the d i f f e r e n c e s i n walking d i s t a n c e s with income l e v e l s i s s i g n i f i c a n t a t the .05 l e v e l . T h i s s u p p o r t s . t h e c o n c l u s i o n t h a t lower income groups are walking s u b s t a n t i a l d i s t a n c e s to attempt to trade o f f p a r k i n g charges w i t h the inconvenience of w a l k i n g . S i n c e walking d i s t a n c e s i n the CBD v a r i e s w i t h i n -come i t might be expected a l s o to vary w i t h o c c u p a t i o n a l groups, w i t h those of the h i g h s t a t u s occupations w a l k i n g s h o r t e r d i s -t a n c e s . T a b l e XV shows t h i s to be g e n e r a l l y the case with p r o -f e s s i o n a l and managerial employees f a v o u r i n g l e s s than 5 minute walking times with h i g h e r percentages i n the lower s t a t u s occu-p a t i o n s walking more than 5 minutes. An e x c e p t i o n i s those who r e p o r t "other" o c c u p a t i o n , which i n c l u d e s craftsmen and l a b o u r -e r s , and who show a tendency to walk l e s s than 5 minutes from t h e i r p a r k i n g l o c a t i o n t o t h e i r work. T h i s i s to be expected s i n c e most of these employees work i n i n d u s t r y on the f r i n g e of the CBD where p a r k i n g i s a v a i l a b l e e i t h e r f r e e from t h e i r employer or a t lower r a t e s than t h a t towards the core. S i g n i -f i c a n c e t e s t s show these d i f f e r e n c e s to be s i g n i f i c a n t a t the .001 l e v e l . Comfort Comfort i s undoubtedly a f a c t o r i n mode c h o i c e , but meaningful q u a n t i f i c a t i o n nor p r e c i s e d e f i n i t i o n s have as y e t e v o l v e d . T h e r e f o r e , i t i s d i f f i c u l t to assess r e l a t i v e comfort 9 7 . i n comparison with those f a c t o r s d i s c u s s e d here. The l i t e r a t u r e has i n c l u d e d such items as a i r c o n d i t i o n e d buses, freedom from crowding, amenities of the r i d e and v e h i c l e , s e c u r i t y , d e s t i -n a t i o n r e l i a b i l i t y , and stop s h e l t e r s . F a c t o r s which are u s u a l l y i n c l u d e d i n convenience, or time u n i t s , may a l s o be more p r o p e r l y c o n s i d e r e d as comfort f a c t o r s . For example, i t may be t h a t w a l k i n g times, w a i t i n g times, t r a n s f e r s and e x t r a v e h i c u l a r a c t i v i t i e s are r e l a t e d t o mode c h o i c e w i t h r e g a r d to the r e l a -t i v e d i s c o m f o r t i n v o l v e d r a t h e r than the time d i s u t i l i t y of these a c t i v i t i e s . T h i s c o u l d be the case i n Vancouver where the p r e c i p i t a t i o n i s h i g h , w i t h inclement weather f o r a substan-t i a l number of days of the y e a r . Regardless of the l e v e l of q u a n t i f i c a t i o n t h e r e i s a c o n v i c t i o n by many pl a n n e r s and p o l i c y makers t h a t comfort weighs h e a v i l y i n the mode c h o i c e c a l c u l u s . There i s l i t t l e doubt t h a t the r e l a t i v e comfort of the automobile, whatever components are i n c l u d e d i n the concept, has been a s i g n i f i c a n t f a c t o r i n i t s growth and use s i n c e World War I I . The r o l e of comfort i n mode c h o i c e i s e v i d e n t from attempts to i n c l u d e a hi g h l e v e l of comfort and amenity f a c t o r s i n r e c e n t r a p i d t r a n -s i t p r o j e c t s . Montreal's rubber t i r e d t r a n s i t v e h i c l e s , i n d i -v i d u a l l y designed s t a t i o n s , and wide . e s c a l a t o r s are examples. San F r a n c i s c o , i n BARTD, has p r o v i d e d f o r an unprecedented c o n c e s s i o n t o comfort and a e s t h e t i c s i n d e s i g n and o p e r a t i o n a l c h a r a c t e r i s t i c s . A c c o r d i n g to pr o m o t i o n a l l i t e r a t u r e BARTD's success depends almost e n t i r e l y on c r e a t u r e comforts. The 98 . o b j e c t as s t a t e d i s to make the t r a i n s above a l l , more com-f o r t a b l e and a t t r a c t i v e than p r i v a t e c a r s . The r e l a t i v e v a l u e of comfort f o r bus commuters i n the c o r r i d o r can be i n f e r r e d from the survey q u e s t i o n n a i r e . Bus r i d e r s were asked to rank those a t t r i b u t e s of the system which were f e l t to need improvement i n order of p r e f e r e n c e . Of the comfort f a c t o r s , to have a s e a t proved to be the most important p r e f e r e n c e f o r improvement wi t h 8.9 p e r c e n t r a t i n g t h i s as f i r s t p r i o r i t y f o r improvement, and 15.5 p e r c e n t r a t i n g i t second. I f i s f o u r t h i n order of p r e f e r r e d improvement. Over 38 p e r c e n t ranked the a b i l i t y to g e t a s e a t as e i t h e r f i r s second, or t h i r d . S h e l t e r a t bus stops had a h i g h e r r a t i n g than b e t t e r l i g h t i n g and a i r c o n d i t i o n i n g , although both these p r e f e r e n c e s came a f t e r improvement i n time and c o s t f a c t o r s . A g r e a t number of respondents d i d not i n d i c a t e a rank o r d e r e d p r e f e r e n c e , e i t h e r by not answering any p a r t of the q u e s t i o n or by only r a n k i n g c e r t a i n items. I f we assume a non-response as i n d i f f e r e n c e to the item, w i t h fewer non-responses i n d i -c a t i n g an i n t e r e s t i n improvement; to be seated r a t e s second i n importance of a l l items t e s t e d . S l i g h t l y more than 37 per-cent were non-respondents, whereas the most important item, express s e r v i c e , had o n l y 19.4 p e r c e n t non-responses. A comparison of a l l items was c a r r i e d out by N.D. Lea and A s s o c i a t e s i n which a l l ranks were weighted by the number of responses, and each item then taken as a percentage of the t o t a l weighted responses. Ranked i n order of impor-tance the r e s u l t s were: 1st Express routes and s e r v i c e 2nd Lower f a r e s 3rd A l l passengers s e a t e d 4 th Frequency of s e r v i c e 5 th S h e l t e r s a t bus stops 6 th Bus r o u t e c l o s e r to home or work 7 th B e t t e r l i g h t i n g and a i r c o n d i t i o n i n g Based on these r e s u l t s f o r bus passengers, comfort and convenience f a c t o r s appear to be l e s s important than t r a v e l time and c o s t f a c t o r s . I t i s w e l l t o note however t h a t these are rankings of p r e f e r e n c e s f o r improvement and do not i n d i c a t e any propen-s i t y f o r changing b e h a v i o r . S i n c e automobile d r i v e r s are not f a c e d w i t h these d i s -comforts , t h e r e i s no way to compare l e v e l s of improvements which would a f f e c t the mode s p l i t . However, t h e r e i s one asp e c t which i s an important comfort f a c t o r to m o t o r i s t s ; and t h a t i s the a b i l i t y to park e a s i l y . In the study c o r r i d o r a l a r g e percen-tage of bus passengers i n d i c a t e d they had switched from c a r to bus, and of those who switched 21.8 p e r c e n t s a i d the d i d so because p a r k i n g was too " d i f f i c u l t . " P a r k i n g d i f f i c u l t y i n t h i s c o n t e x t may mean del a y , or p o s s i b l y too h i g h a p r i c e , but i t a l s o undoubtably has some comfort component as w e l l . The f r u s t r a t i o n s of p a r k i n g , and the i n s e c u r i t y of being f a c e d 1 0 0 . w i t h a d i f f i c u l t p a r k i n g s i t u a t i o n each day may w e l l be a f a c t o r i n s w i t c h i n g to t r a n s i t . PRINCIPAL FINDINGS The f o r e g o i n g d e s c r i p t i o n of the socioeconomic and be h a v i o r p r o f i l e s of each of the c l i e n t groups has r e l a t e d the case study c o r r i d o r to the body of l i t e r a t u r e and has p o i n t e d out new hypotheses. I t has been shown t h a t most socioeconomic c h a r a c t e r i s -t i c s of commuters to the CBD are s i g n i f i c a n t l y d i f f e r e n t from those of non-CBD commuters. For CBD commuters, c l i e n t groups are d i f f e r e n t f o r each mode and the socioeconomic c h a r a c t e r i s t i c s of each mode's c l i e n t group are a f a c t o r i n how the a t t r i b u t e s of the system are v a l u e d . Consequently, the e f f e c t s of p o l i c y o p t i o n s a c t a t t h r e e l e v e l s of socioeconomic space d e f i n e d by the study c o r r i d o r : t h a t space which d e f i n e s the CBD commuter, t h a t space which d e f i n e s the c l i e n t group f o r each mode, and t h a t space which d e f i n e s the b e h a v i o r p a t t e r n of each c l i e n t group. The former i s of i n t e r s t only because s e t s of p o l i c y o p t i o n s concerned w i t h changes i n the c o r r i d o r system w i l l have i n d i r e c t e f f e c t s of those c o r r i d o r c l i e n t groups which are not d i r e c t l y a f f e c t e d by system changes. For example, i f a p a r k i n g and/or p r i c i n g p o l i c y i n the CBD i s s u c c e s s f u l i n s h i f t i n g the mode s p l i t i n favour of t r a n s i t , thus r e l i e v i n g automobile c o n g e s t i o n i n the c o r r i d o r , commuters t r a v e l l i n g through the 101. c o r r i d o r to p o i n t s o u t s i d e the CBD which are thereby not sub-j e c t to the p o l i c y changes may s w i t c h to automobiles, or more automobile t r i p s may be generated, because of the i n c r e a s e d s e r v i c e . There appears to be a r e l a t i o n s h i p between the s o c i o -economic space of c l i e n t groups and the mode used f o r the journey to work. For each mode, group socioeconomic c h a r a c t e r i s t i c s are r e l a t i v e l y homogeneous compared to the d i f f e r e n c e i n c h a r a c t e r -i s t i c s between modes. Male commuters- are c a r o r i e n t e d , female ones bus o r i e n t e d . Commuters i n the prime working age groups of 40-60 are car o r i e n t e d , w h i l e younger and o l d e r age groups are bus o r i e n t e d . I n d i c a t i o n s are t h a t s u b s t a n t i a l commuters i n the 20-40 age group p r e f e r the bus. O c c u p a t i o n a l s t r u c t u r e i s r e l a t e d t o mode c h o i c e somewhat d i f f e r e n t l y than expected. A hig h p r o p o r t i o n of managers, and p r o f e s s i o n a l employees use the bus, an unexpected f i n d i n g . A l s o a substan-t i a l p r o p o r t i o n of u n s k i l l e d workmen and c l e r i c a l employees are car o r i e n t e d , groups which are o f t e n though to be t r a n s i t " c a p t i v e s . " S e c r e t a r i e s and s a l e s workers are t r a n s i t o r i e n t e d as expected. Car ownership i s h i g h i n t h i s case and may be expected to moderate the u s u a l l y h i g h c o r r e l a t i o n between car ownership and mode s p l i t . Income shows the expected t r e n d w i t h h i g h income households a s s o c i a t e d w i t h car mode and low income with bus use. 1 0 2 . The a n a l y s i s shows tendencies toward d i f f e r e n t i a t e d socioeconomic c h a r a c t e r i s t i c s of c l i e n t groups f o r each mode. The b e h a v i o r p r o f i l e s of each mode group d e s c r i b e what modal a t t r i b u t e s are important to the v a r i o u s socioeconomic groups i n e v a l u a t i n g the r e l a t i v e m e r i t s of each component of the system. One apparent c o n t r a d i c t i o n emerges. While the h i g h e r income groups t r a v e l f u r t h e r t o workplace than low income groups, these groups seem to be more s e n s i t i v e to the r e l a t i v e t r a v e l time between modes. The e x p l a n a t i o n f o r t h i s phenomenon i s t h a t what appears to be an e f f e c t of r e l a t i v e t r a v e l time i s due to an i n t e r v e n i n g v a r i a b l e such as r e s i d e n t i a l amenity or a h i g h l e v e l of comfort and amenity on the t r a n s i t system. An a n a l y s i s of v a r i a n c e of t r a v e l time by each of the modes a g a i n s t income s u b s t a n t i a t e s t h i s c o n c l u s i o n , and the v a r i a t i o n i n the t r a v e l times f o r d i f f e r e n t income groups wipes out the e f f e c t of t r a v e l time d i f f e r e n c e s of the modes. I t may be t h a t r e l a t i v e t r a v e l times may not be an important f a c t o r i n mode c h o i c e as i t r e l a t e s to income, except to the e x t e n t i t i s a proxy f o r o t h e r v a r i a b l e s . However, t h i s c o n c l u s i o n needs to be supported by a g r e a t e r range of t r a v e l times and t r a v e l time d i f f e r e n c e s than i s a v a i l a b l e f o r t h i s s i n g l e c o r r i d o r . C l e a r l y , o c c u p a t i o n shows a d i f f e r e n t p a t t e r n of time e f f e c t s than income. D i f f e r e n t o c c u p a t i o n a l groups v a l u e t r a v e l time a t t r i b u t e s d i f f e r e n t l y , w i t h some non-expected t e n d e n c i e s . For example, the p r o f e s s i o n a l group which would be a s s o c i a t e d 1 0 3 . w i t h h i g h e r incomes, have s h o r t e s t t r a v e l times i n t h e i r r e s -p e c t i v e modes. I t appears t h a t p r o f e s s i o n a l employees are more time s e n s i t i v e than the h i g h e r income group they belong t o, and t h e r e f o r e have d i f f e r e n t mode c h o i c e h a b i t s and r e s i d e n c e -workplace r e l a t i o n s h i p s . The r e l a t i o n s h i p o f o c c u p a t i o n , s e p a r a t e from income, w i t h t r a v e l times s u b s t a n t i a t e s the hyp o t h e s i s t h a t the CBD o c c u p a t i o n a l s t r u c t u r e and the r e l a t i v e modal c h a r a c t e r i s t i c s s e r v i n g the CBD are r e l a t e d . The c h o i c e of mode i s dependent a t l e a s t i n p a r t upon the p e r c e i v e d d i f f e r e n c e s between the modes. Only however to the degree i n d i v i d u a l s p e r c e i v e one mode to be advantageous and a c t u a l l y use t h a t mode. However, i t appears t h a t most i n d i -v i d u a l s i n t h i s case a c t r a t i o n a l l y a c c o r d i n g to p e r c e i v e d a t t r i b u t e s . Auto d r i v e r s f a l l i n t o two c a t e g o r i e s : those who p e r c e i v e c a r f a s t e r and use t h a t mode, and those who r e p o r t they do not know bus t r a v e l times. R e l a t i v e l y few c a r u s e r s , who p e r c e i v e d the bus t o be f a s t e r , used t h e i r c a r s f o r the journey t o work. Those who were i g n o r a n t of bus t r a v e l times i n c r e a s e d w i t h income l e v e l and o c c u p a t i o n a l s t a t u s . A g r e a t number of these commuters are able to n e g o t i a t e a h i g h l e v e l of comfort and convenience i n d e s i g n a t e d and f r e e p a r k i n g , and t h e r e f o r e are never f a c e d with the bus a l t e r n a t i v e . Over 57 p e r c e n t of car users s a i d they never use the bus. On the oth e r hand a s u b s t a n t i a l p r o p o r t i o n of bus r i d e r e p o r t the c a r to be f a s t e r , but use the bus. These i n c l u d e c a p t i v e s . 1 0 4 . P o l i c y o p t i o n s which i n c l u d e p r i c i n g as a c o n t r o l mechanism f o r c o n g e s t i o n or the m a n i p u l a t i o n of mode s p l i t must contend with e x i s t i n g p r i c i n g p r a c t i c e s and the i n s e n s i -t i v i t y of c l i e n t groups to p r i c e changes. E f f e c t s of changing the p r i c e of p a r k i n g i s not as s t r a i g h t forward as g e n e r a l l y presumed. F i r s t , i t i s obvious t h a t a g r e a t number of c a r d r i v e r s f a c e no charge f o r p a r k i n g . S i n c e p a r k i n g s t a l l s f o r e x e c u t i v e s i s becoming a c o n d i t i o n of tenancy i n newer o f f i c e b u i l d i n g s , s u p p l i e d f r e e to the user by the tenant, and s i n c e , the CBD i s becoming more and more a managerial and f i n a n c i a l c e n t e r i t i s p r o b a b l e t h a t the p r o p o r t i o n of CBD employees who have " f r e e " p a r k i n g w i l l i n c r e a s e . P r i c i n g p o l i c i e s w i l l have v i r t u a l l y no e f f e c t on t h i s group. I t i s a l s o d i f f i c u l t to see how any m u n i c i p a l r a t e s t r u c t u r e or t a x i n g scheme would e f f e c t t h i s s i t u a t i o n d i r e c t l y . ( I t might, by making the oppor-t u n i t y c o s t of p o t e n t i a l p a r k i n g s t a l l s i n a development g r e a t e r , e l i m i n a t e some spaces f o r a h i g h e r and b e t t e r use i f e x e c u t i v e p a r k i n g i s otherwise p r o v i d e d a t no c o s t to him). Secondly, i t appears t h a t p a r k i n g c o s t and p a r k i n g convenience i s comple-mentary, wi t h the mixture dependent upon the socioeconomic s t r u c t u r e of the c l i e n t . While t h i s r e l a t i o n s h i p i s confused by the f a c t t h a t r e l a t i v e l y l a r g e numbers of h i g h e r income com-muters have f r e e p a r k i n g thereby w i p i n g out the p o s i t i v e r e l a -t i o n s h i p expected between income and p a r k i n g charge, i t i s apparent t h a t low income commuters walk f u r t h e r to a v o i d h i g h p a r k i n g r a t e s . Low s t a t u s income and o c c u p a t i o n a l groups 1 0 5 . g e n e r a l l y w i l l t o l e r a t e s u b s t a n t i a l walking d i s t a n c e s to be a b l e to use t h e i r cars f o r the work journey. Comfort, w i t h the e x c e p t i o n of being a b l e to o b t a i n a s e a t , does not weigh h e a v i l y as f a c t o r s which bus passengers d e s i r e as improvements. A f t e r express s e r v i c e s and lower f a r e s bus r i d e r s would l i k e to be s e a t e d f o r the t r i p . However, s h e l -t e r s a t bus stops and b e t t e r l i g h t i n g and a i r c o n d i t i o n e d buses are not as important as t r a v e l time, c o s t , and convenience f a c -t o r s . P a r t of the r e s u l t s of t h i s t e s t i s r e l a t e d to the e x i s -t i n g l e v e l of s e r v i c e , and i s not i n d i c a t i v e of an o b j e c t i v e h i e r a r c h y of importance. F r u s t r a t i o n s of p a r k i n g may be a d i s c o m f o r t f o r auto d r i v e r s . These r e s u l t s however, do not a l l o w any i n f e r e n c e w i t h r e g a r d to the e f f e c t improving comfort would have on a t t r a c t i n g m o t o r i s t s to the bus system. CHAPTER IV MULTIVARIATE ANALYSIS OF INTERMODAL DEMAND This chapter i s an a n a l y s i s , u s i n g m u l t i v a r i a t e s t a t i s t i c a l procedures, of b e h a v i o r on the system; and how i t i s r e l a t e d t o mode c h o i c e and the socioeconomic s t r u c t u r e of those u s i n g the two modes to get to work. PREPARATION OF DATA MATRIX S u b s t a n t i a l p r e p a r a t i o n was necessary to reduce the q u e s t i o n n a i r e responses to allow p r o c e s s i n g by h i g h speed com-p u t e r , and to prepare the m a t r i c e s necessary f o r the m u l t i -v a r i a t e s t a t i s t i c a l a n a l y s i s . Each item of the survey q u e s t i o n -n a i r e was examined and r e f o r m a t t e d . S i n c e many answers were a l p h a b e t i c a l l y coded on the o r i g i n a l cards a c o n v e r s i o n program was w r i t t e n to format a d a t a m a t r i x which was machine compatible. The c o n v e r s i o n program i s shown i n Appendix C. S i n c e the auto q u e s t i o n n a i r e s and bus q u e s t i o n n a i r e s were of d i f f e r e n t d e s i g n the program a l s o converted both t o a common format. A l p h a b e t i -c a l codes f o r zone d e s i g n a t i o n s were changed t o n u m e r i c a l codes, and those f o r door-to-door t r a v e l times were g i v e n t h e i r o r i g i n a l t r a v e l time d e s i g n a t i o n s i n i n t e r v a l s c a l e . The c o n v e r s i o n program was designed a l s o to r e o r g a n i z e the r e l a t i v e t r a v e l time q u e s t i o n s so t h a t d i f f e r e n c e s and r a t i o s c o u l d be c a l c u l a t e d . 107. Q u e s t i o n n a i r e responses were i n the form of c a t e -g o r i c a l d a t a . T h i s was handled i n s e v e r a l ways. Where the c a t e g o r i e s were s c a l e d i n equal i n t e r v a l s the mid-point of the category was taken to be the v a l u e f o r a l l responses i n the c a t e g o r y . Where the s c a l e was open, or i f i n t e r v a l s were not eq u a l , the response was reduced to o r d i n a l s c a l e d v a l u e s and a code a s s i g n e d to each c a t e g o r y . An example where t h i s was done i s q u e s t i o n 13 and 14 of the auto q u e s t i o n n a i r e c o n c e r n i n g t r a v e l times to and from the v e h i c l e . The r e s u l t i n g s c a l e was a high order o r d i n a l s c a l e . Most of the o r d i n a l codes are b e t -t e r than a simple rank o r d e r s i n c e across most of the s c a l e (the end c a t e g o r i e s excluded) the ranks were based on equal d i s t a n c e between c a t e g o r i e s . Occupation, f o r the f i r s t s e r i e s of t e s t s , was o r d i n a l i z e d i n accordance w i t h B l i s h e n ' s S o c i o -economic Index of Occupations i n Canada.''" With the e x c e p t i o n of door-to-door t r a v e l time, the i n t e r v a l s c a l e d responses were grouped and category mid-points used as the measure o f the v a r i a b l e under c o n s i d e r a t i o n . Because the number of c a t e g o r i e s i n some cases were l e s s than 10, the minimal number recommended f o r s t a t i s t i c a l 2 accuracy by McNemar, Sheppard's c o r r e c t i o n f a c t o r f o r grouping was a p p l i e d . The theory behind t h i s c o r r e c t i o n i s as f o l l o w s . When data are grouped and a l l o b s e r v a t i o n s assumed a t the mid-p o i n t , i t hides the f a c t t h a t i n d i v i d u a l o b s e r v a t i o n s w i t h i n a category i n t e r v a l c l u s t e r toward the d i r e c t i o n of the mean, r a t h e r than a t the mid-point as assumed. That i s , f o r c a t e g o r i e s 1 0 8 . to the l e f t of the mean o b s e r v a t i o n s would tend to c l u s t e r a t the r i g h t hand s i d e of the i n t e r v a l , w h i l e f o r c a t e g o r i e s to the r i g h t of the mean the o b s e r v a t i o n s would c l u s t e r toward the l e f t of the i n t e r v a l . Thus the standar d d e v i a t i o n o f the grouped data would appear l a r g e r than t h a t based on i n d i v i d u a l o b s e r v a t i o n s . Sheppard's c o r r e c t i o n f a c t o r i s a p p l i e d to the standard d e v i a t i o n by r e d u c i n g the observed s t a n d a r d d e v i a t i o n by a f a c t o r which r e l a t e s the a c t u a l i n t e r v a l s i z e to one i n which no d i f f e r e n c e e x i s t s between the standar d d e v i a t i o n f o r grouped and ungrouped d a t a . * bus q u e s t i o n n a i r e data from the two c a r d decks i n t o a s i n g l e d ata format, and t r a n s c r i b e d the data m a t r i x to magnetic tape. The data tape m a t r i x a r r a y s a l l t r a v e l and socioeconomic i n f o r -mation f o r each i n d i v i d u a l who has a c h o i c e of mode, where c h o i c e i s d e f i n e d by having a t l e a s t one car i n the household. P r e p a r a t i o n of Score M a t r i c e s as needed f o r each t e s t . F or the f i r s t s e r i e s of t e s t s , the sc o r e m a t r i x c o n s i s t s of an a r r a y of o r i g i n a l data and t r a n s -formations s e l e c t e d from the data m a t r i x , as w e l l as new data i n p u t . Blank e n t r i e s , i n c o r r e c t coding of the o r i g i n a l c a r d s , r e s u l t i n g i n i m p o s s i b l e v a l u e s o f the v a r i a b l e s , and o t h e r The data c o n v e r s i o n program t r a n s l a t e d both auto and Score m a t r i c e s were developed from the data m a t r i x i n t e r v a l s . where i = number of 109. anomolies i n the data m a t r i x were a l s o screened out a t t h i s s t a g e . T h i s process r e s u l t e d i n a mat r i x of 14 v a r i a b l e s and 2211 i n d i v i d u a l e n t r i e s , w i t h 1244 auto and 967 bus u s e r s . Appendix D shows the computer program to develop t h i s m a t r i x (Score M a t r i x #1), and to t r a n s c r i b e i t to magnetic tape. The v a r i a b l e s s e l e c t e d f o r the t e s t s were the s o c i o -economic c h a r a c t e r i s t i c s which were a v a i l a b l e i n the survey and those v a r i a b l e s which measured the a c t u a l t r a v e l b e h a v i o r of the i n d i v i d u a l . The b e h a v i o r a l v a r i a b l e s are those which r e f l e c t performance a t t r i b u t e s of the system and which can be manipula-ted i n a g e n e r a l i z e d p a r k i n g p o l i c y . Those used denote the br o a d e s t concept of p a r k i n g p o l i c y which i n c o r p o r a t e s park and r i d e p o t e n t i a l , as w e l l as the CBD p a r k i n g system. Inherent to the i d e a of a b s t r a c t mode as measured by the a t t r i b u t e s of the system i s the concept of a multimodal system i n which t r a n s f e r s from one mode to another i s p o s s i b l e . The f a c i l i t i e s f o r such a concept may be viewed w i t h i n a park and r i d e system and t h e r e f o r e v i r t u a l l y a l l performance f a c t o r s c o u l d be a d j u s -ted by such a system. R e s i d e n t i a l t r a v e l time o v e r a l l t r a v e l time, CBD t r a v e l times, frequency a t the i n t e r f a c e and the over-a l l c o s t c o u l d be as important as p a r k i n g charges. S i n c e any multimodal system, such as park and r i d e , i n c o r p o r a t e s to some degree a l l of these elements i t i s necessary t h a t the i n f l u e n c e of each be known as i n p u t s to any r e a l i s t i c p a r k i n g p o l i c y . 110. Age. The age c a t e g o r y of each respondent was coded between 1 and 4. Occupation. The o c c u p a t i o n a l c a t e g o r i e s i n the survey were r e o r g a n i z e d i n a new h i e r a r c h y i n accordance w i t h B l i s h e n ' s socioeconomic index f o r o c c u p a t i o n s . B l i s h e n d e v i s e s an i n t e r v a l s c a l e d index of o c c u p a t i o n s i n Canada. The o c c u p a t i o n v a r i a b l e s i n the m u l t i v a r i a t e a n a l y s i s were rank ordered a c c o r d i n g to B l i s h e n ' s h i e r a r c h y . A code number between 1 and 6 was a s s i g n e d to the s i x c a t e g o r i e s of the work purpose t r i p i n accordance w i t h the rank of t h a t o c c u p a t i o n . Car Necessary f o r Work. The q u e s t i o n "how o f t e n i s i t a b s o l u t e l y necessary to use your car d u r i n g the day" was coded from 1 to 4 to d e s i g n a t e "never," "very seldom," "once a week" or " f r e q u e n t l y . " A l l bus passengers were coded "1" ( i . e . as never having to use the c a r f o r work). I t i s p o s s i b l e t h a t those bus passengers responding on the day of the survey would sometimes use t h e i r c a r s d u r i n g the day. However, symmetry i s o r d i n a r i l y assumed i n o r i g i n d e s t i n a t i o n c r o s s s e c t i o n a l be-h a v i o r i n which e r r o r s are presumed to be compensating. The t y p i c a l example i s t h a t t r a f f i c measured i n one d i r e c t i o n d u r i n g a 24 hour p e r i o d w i l l be r e f l e c t e d i n the o p p o s i t e d i r e c t i o n , even i f the survey shows unequal d i r e c t i o n a l f l o w s , and the flows are thus a r b i t r a r i l y b a l a n c e d . For t h i s reason i f a commuter used the bus to work i t i s obvious he would not use h i s car d u r i n g the day of the survey and t h e r e f o r e , f o r t h a t page 111 omit ' ted i n page n u m b e r i n g t r i p on t h a t day, i t i s e q u i v a l e n t to never u s i n g the c a r . Presumably some c a r user who took h i s car o n l y t h a t day and on no o t h e r would balance out the bus passenger. Car Ownership. T h i s v a r i a b l e was coded 1 to 4 d e s i g -n a t i n g none, one, two, three o r more cars i n the household. S i n c e the mode c h o i c e a n a l y s i s t o f o l l o w i s f o r " c h o i c e " t r i p s , o n l y those households which r e p o r t e d owning one or more ca r s were i n c l u d e d i n the s c o r e m a t r i x . Income. Income was coded 1 to 4 d e s i g n a t i n g $4000, $4-8000, $8-12000, and $12,000 c a t e g o r i e s . Car A v a i l a b i l i t y . S i n c e household ownership of an automobile may not r e f l e c t the a c t u a l a v a i l a b i l i t y of a c a r f o r a g i v e n t r i p , a proxy based on the e s t i m a t e d a v a i l a b i l i t y of a c a r , and the c o m p e t i t i o n amongst members of the household f o r c a r use was i n c l u d e d . T h i s v a r i a b l e accounts f o r d i f f e r e n t l e v e l s of c a r ownership, persons per household (zonal average), and income: ...... PERSONS PER HOUSEHOLD X LOG INCOME Car A v a x l a b i l i t y C A R S p E R HOUSEHOLD Th i s proxy v a r i a b l e d e f i n e s the c o m p e t i t i o n between members of the household i n terms of the number of persons i n the household and the number of c a r s owned, m o d i f i e d by the demand f o r t r a v e l . I f the car was purchased f o r commuting o n l y , the a v a i l a b i l i t y of a c a r f o r commuting i s a simple r e l a t i o n s h i p between the number of commuters and the number of c a r s owned. I f t here i s one c a r per commuter th e r e would be no c o m p e t i t i o n f o r the use of the c a r and the mode c h o i c e would be r e l a t e d t o f a c t o r s o t h e r than car ownership. I n t u i t i v e l y , the use of t r a n s i t would i n c r e a s e as t h i s simple r a t i o decreased from the v a l u e of one. However, the number of persons and ca r s owned per household f o r commuting must be r e l a t e d to c o m p e t i t i o n from o t h e r purpose t r i p s as w e l l , such as shopping and s o c i a l - r e c r e a -t i o n t r i p s c a r r i e d out by non-commuting members of the f a m i l y . The income f a c t o r takes t h i s i n t o account. As income per person i n c r e a s e s the number of t r i p s demanded i n c r e a s e s . That i s , as Warner s t a t e s : "the more each i n d i v i d u a l has to spend, the more 3 o f t e n he can t r a v e l f o r the purpose of spending." But there i s a l i m i t to the number of t r i p s , and a l s o p o s s i b l e econo-mies of s c a l e . T h e r e f o r e i t i s p o s t u l a t e d t h a t the d e s i r e f o r i n d i v i d u a l t r a v e l i s r e l a t e d to income, but a t a d e c r e a s i n g r a t e , and the l o g of income becomes the proper m o d i f i e r f o r car a v a i l a b i l i t y . Income i s the r e p o r t e d i n d i v i d u a l income, and persons per household i s the average number of persons per house-h o l d i n each zone. Persons per household i s taken from the 1966 P o p u l a t i o n Census t r a c t s and converted t o the survey zones. Cars per household i s t h a t r e p o r t e d by survey respondents. Hour End. T h i s v a r i a b l e i s the r e p o r t e d time of a r r i v a l a t work. I t was reasoned t h a t mode c h o i c e i s r e l a t e d to work hours f o r two reasons. F i r s t i f a commuter was to l e a v e home and a r r i v e a t work a t a time when bus frequency was hi g h he would be more l i k e l y , to take the bus, and v i c e v e r s a . Secondly, the " l a g " time f o r bus t r a v e l i s r e l a t e d to r e q u i r e d time of 114. a r r i v a l a t work. For example, a bus commuter may be r e q u i r e d to a r r i v e a t h i s work p l a c e some s u b s t a n t i a l time b e f o r e he needs to r e p o r t f o r work because of the bus frequency at. h i s r e s i d e n c e l o c a t i o n . For example, the f i r s t bus a v a i l a b l e may put him a t h i s work p l a c e 15 minutes b e f o r e the s t a r t i n g hour, whereas the next bus may make him l a t e . The work p l a c e time l a g between h i s " f o r c e d " a r r i v a l time and r e q u i r e d s t a r t i n g time c o u l d be a powerful i n c e n t i v e to use a c a r , i f one i s a v a i l a b l e . R e s i d e n t i a l T r a v e l Time. T h i s v a r i a b l e measures the l e n g t h of time to t r a v e l from the s t a r t of the work journey to the bus stop or to a c a r . Although the o r i g i n a l survey times were c a t e g o r i z e d (0 minutes, 1-3 minutes, 3-5 minutes, 5-10 minutes and 10 or more minutes) the i n t e r v a l s were unequal and a s i g n i f i c a n t number of responses were i n the open ended c a t e -gory (10 or more min u t e s ) , i t was d e c i d e d to t r e a t t h i s v a r i a b l e as an o r d i n a l s c a l e d response. T h e r e f o r e the c a t e g o r i e s were coded from 1 to 5 i n c l u s i v e . CBD T r a v e l Time. T h i s v a r i a b l e i s the walking time from the p a r k i n g l o c a t i o n or bus stop to f i n a l d e s t i n a t i o n . I t was a l s o o r d i n a l i z e d i n the same way as r e s i d e n t i a l t r a v e l time, s i n c e a l l c o n d i t i o n s were p a r a l l e l . O v e r a l l T r a v e l Time. T h i s measures door-to-door t r a v e l time f o r both auto and bus passengers i n 5 minute increments. These increments are probably the minimum which can be p e r c e i v e d 115. by u s e r s . That i s , p e r c e i v e d and r e p o r t e d times are g i v e n to the n e a r e s t 5 minutes, and any f i n e r breakdown probably meaningless i n terms of s u b j e c t i v e responses. P a r k i n g Charge. P a r k i n g charges l e v i e d are the mani-f e s t a t i o n of o u t - o f - p o c k e t expenses f o r automobile d r i v e r s , as are f a r e s f o r t r a n s i t r i d e r s . Most commuters pay p a r k i n g fees by the month. Reported monthly fee s were conv e r t e d to d a i l y r a t e s to be compatible w i t h the o t h e r components of d a i l y t r a v e l . On the assumption there are 20.8 working days per month, l e s s 10 s t a t u t o r y h o l i d a y s per year (or .8 per month) the r e p o r t e d monthly r a t e i s e q u i v a l e n t to the r e p o r t e d d a i l y r a t e i f d i v i d e d by 20 (20.8 - 0.8). O c c a s i o n a l l y r e s e a r c h e r s s p l i t p a r k i n g f e e s , w i t h one h a l f of the f e e a s s i g n e d to the journey to work, and one h a l f t o the journey from work. I t was however reasoned t h a t the p e r c e i v e d p a r k i n g charge would be the t o t a l charge per day, s i n c e t h i s would be the manner i n which the t r a n s f e r of money would take p l a c e . T h i s i s p a r t i c u -l a r l y t r u e of s u b s c r i b e r s , who i t i s p o s t u l a t e d , would not attempt to c o s t a s i n g l e t r i p . F a r e . Both t r a n s i t agencies r e p o r t e d t h a t most f a r e s are i n f a c t commuted f a r e s , but no p r e c i s e breakdown i s a v a i l -a b l e . T h e r e f o r e i t was assumed t h a t a l l commuters would take advantage of commuted f a r e s where a v a i l a b l e . The one-way f a r e s were then doubled to conform wi t h the nature of the p e r c e p t i o n of p a r k i n g charges. 1 1 6 . P a r k i n g Charge/Income. This v a r i a b l e i s a proxy i n c o r p o r a t i n g p a r k i n g charge d i v i d e d by income, on the premise t h a t the p a r k i n g r a t e as an i n f l u e n c e i n mode c h o i c e would be more meaningful i f r e l a t e d to income. Frequency. T h i s was taken as the average frequency over the p e r i o d between 7 a m - 9 a m . S i n c e the minimum d i f f e r e n c e i n average frequency f o r commuters i s 5 minutes, and s i n c e the o r i g i n a l survey d i d not r e p o r t exact f r e q u e n c i e s f a c i n g i n d i -v i d u a l t r a v e l l e r s , i t was d e c i d e d t h a t average frequency f o r each zone would adequately d e s c r i b e the p e r c e i v e d dimension of t r a n s i t frequency. S t a n d a r d i z a t i o n of Scores The v a r i a b l e s are measured i n d i f f e r e n t s c a l e s of time, space and d o l l a r u n i t s . For those t e s t s which i n c l u d e d socioeconomic v a r i a b l e s w i t h performance v a r i a b l e s the s c o r e m a t r i c e s were s t a n d a r d i z e d and a d j u s t e d by Sheppard's c o r r e c t i o n f a c t o r by d i v i d i n g each row score by the c o r r e c t e d s t a n d a r d d e v i a t i o n of the v a r i a t e . S t a n d a r d i z a t i o n , i n which the mean of the v a r i a t e over the p o p u l a t i o n i s zero and the s t a n d a r d d e v i a t i o n equal to u n i t y was necessary i n some t e s t s to reduce both s e t s of v a r i a t e s (the socioeconomic ones and the b e h a v i o r ones) to the same m e t r i c . S t a n d a r d i z a t i o n of the v a r i a t e s has 4 no e f f e c t on the r e s u l t s of the a n a l y s i s . Comparative t e s t s 117. on the second s e r i e s of d i s c r i m i n a n t t e s t s showed n e g l i g i b l e d i f f e r e n c e s i n r e s u l t s between raw scores and s t a n d a r d i z e d s c o r e s a d j u s t e d by Sheppard's c o r r e c t i o n and t h e r e f o r e raw s c o r e s were used f o r some t e s t s . The computer program f o r s t a n d a r d i z e d s c o r e s i s shown i n Appendix E. The data m a t r i x was e d i t e d to remove c a r cassengers, zero e n t r i e s , and those bus passengers who had no c a r a v a i l a b l e f o r the work t r i p , where c a r a v a i l a b i l i t y was d e f i n e d by owning a t l e a s t one c a r . The r e s u l t i n g s c o r e m a t r i x was t r a n s f e r r e d to magnetic tape, and c o n s i s t e d of 1244 car d r i v e r s and 967 bus passengers. S e v e r a l hypotheses about the dimensions of i n t e r m o d a l demand suggested i n the p r e v i o u s chapter r e q u i r e t e s t i n g . These ar e : (1) t h a t b e h a v i o r on the system i s r e l a t e d to the s o c i o -economic c h a r a c t e r i s t i c s of each mode's c l i e n t group, (2) t h a t the mode c h o i c e i s a f u n c t i o n of both socioeconomic s t r u c t u r e of the user and system performance, and (3) t h a t i n d i v i d u a l b e h a v i o r p r o f i l e s can be used to d e f i n e each mode's c l i e n t group. In a d d i t i o n , one o t h e r p o i n t needs to be i n v e s t i g a t e d : the r e l a t i v e i n f l u e n c e of those performance f a c t o r s which c o u l d c o n c e i v a b l y be a p a r t of an i n t e r m o d a l , park and r i d e system. INTERDEPENDENCE OF SOCIOECONOMIC STRUCTURE AND SYSTEM  PERFORMANCE What are the i n t e r d e p e n d e n c i e s between the s o c i o -economic s t r u c t u r a l c h a r a c t e r i s t i c s of the c o r r i d o r and b e h a v i o r towards modal a t t r i b u t e s ? The r e l e v a n t s t r u c t u r a l dimensions 1 1 8 . and t h e i r i n t e r d e p e n d e n c i e s w i t h behavior dimensions g i v e s a c l u e t o the u n d e r l y i n g p a t t e r n of the mode c h o i c e d e c i s i o n . The primary r e s e a r c h q u e s t i o n s are (a) i s socioeconomic s t r u c -t u r e of each modal c l i e n t group s i g n i f i c a n t l y r e l a t e d to the performance of the system of the CBD and (b) how are the two s e t s of v a r i a b l e s which d e s c r i b e these concepts combined i n maximizing the i n t e r a c t i o n between the s e t s . T h i s q u e s t i o n r e c o g n i z e s the r e c i p r o c a l e f f e c t of socioeconomic s t r u c t u r e and system performance i n the d e c i s i o n p rocess of the i n d i v i d u a l and i n f e r s t h a t these r e l a t i o n s h i p s may be d i f f e r e n t f o r each c l i e n t group. That i s ; f i r s t , t h a t mode c h o i c e i s not o n l y dependent on socioeconomic s t r u c t u r e and system performance but t h a t the c h o i c e d e c i s i o n a l s o causes changes i n these con-c e p t s . For example, the d e c i s i o n to purchase a c a r , or change household l o c a t i o n c o u l d be the r e s u l t of making a p r i o r d e c i -s i o n on modal c h o i c e . Secondly, i t r e c o g n i z e s t h a t each modal c l i e n t group puts a v a l u e o r i e n t a t i o n on the a t t r i b u t e s of the system i n accordance w i t h h i s s t r u c t u r a l c h a r a c t e r i s t i c s . That i s , f o r example, we might expect t h a t car d r i v e r s may show an interdependence between income and time f a c t o r s , whereas bus r i d e r s may show s i g n i f i c a n t interdependency between income and c o s t f a c t o r s . We assume moreover t h a t each i n d i v i d u a l ' s d e c i -s i o n c a l c u l u s i s such t h a t e q u i l i b r i u m occurs when the i n t e r -dependence between h i s socioeconomic and b e h a v i o r a l c h a r a c t e r -i s t i c s i s maximized. T h i s assumption, based on e x t e n s i v e e m p i r i c a l f i n d i n g s t h a t s p a t i a l s t r u c t u r e and t r a n s p o r t a t i o n 1 1 9 . i s i n t e r r e l a t e d , adds c o n c e p t u a l r e a l i t y t o t h e i d e a of m a x i -m i z i n g two s e t s o f v a r i a b l e s where o t h e r w i s e t h e r e may be o n l y " a r t i f i c i a l " r e l a t i o n s h i p s b r o u g h t o u t by t h e n a t u r e of t h e s t a t i s t i c s . C a n o n i c a l c o r r e l a t i o n a n a l y s i s as o u t l i n e d by 5 6 Anderson, and Co o l e y and Lohnes i s a s t a t i s t i c a l t e c h n i q u e t o b r i n g o u t t h e r e l a t i o n s h i p s between v a r i a t e s when c o r r e l a -t i o n s between two s e t s o f v a r i a t e s a r e i n some sense m a x i m i z e d . C a n o n i c a l c o r r e l a t i o n a n a l y s i s i s a g e n e r a l i z e d e x t e n s i o n o f m u l t i p l e l i n e a r r e g r e s s i o n a n a l y s i s w i t h b o t h m u l t i p l e dependent as w e l l as m u l t i p l e i n d e p e n d e n t v a r i a b l e s . By m u l t i p l e l i n e a r r e g r e s s i o n i t i s p o s s i b l e t o s t r a t i f y t h e s o c i o e c o n o m i c v a r i a b l e s i n t o s e p a r a t e t e s t s and i n t u r n d e t e r m i n e t h e w e i g h t i n g on t h e b e h a v i o r a l v a r i a b l e s w h i c h would g i v e t h e maximum c o r r e l a t i o n . But m u l t i p l e r e g r e s s i o n does n o t c o n s i d e r the r e l a t i o n s h i p s among t h e s o c i o e c o n o m i c v a r i a b l e s . The p r e v i o u s c h a p t e r showed m u l t i p l e i n t e r r e l a t i o n s h i p s among t h e s e t s o f s o c i o e c o n o m i c and b e h a v i o r v a r i a b l e s . F o r example, t h e r e l a t i o n s h i p between i n -come and the manner i n wh i c h d i f f e r e n t a t t r i b u t e s were v a l u e d was i n t u r n dependent upon o c c u p a t i o n . C a n o n i c a l c o r r e l a t i o n a n a l y s i s a l l o w s some e x p l a n a t i o n o f t h e s e m u l t i p l e r e l a t i o n s h i p s i n t h a t i t t e l l s us how the two s e t s o f v a r i a b l e s a r e r e l a t e d t o each o t h e r and how t h e v a r i a b l e s w i t h i n each s e t i n f l u e n c e the r e l a t i o n s h i p . C a n o n i c a l c o r r e l a t i o n i s the maximum c o r r e -l a t i o n between t h e l i n e a r f u n c t i o n s o f t h e two s e t s o f v a r i a b l e s . 120 . However, s e v e r a l l i n e a r combinations of the two se t s are pos-s i b l e and each p a i r e x t r a c t e d i s maximally c o r r e l a t e d but or t h o g o n a l (independent) of the p r e v i o u s d e r i v e d combinations. Assume there are p socioeconomic v a r i a b l e s , X. ,X_,X_, . . . ,X ; and q behavior v a r i a b l e s X ,-, ,X , n,X X ; 1 2 3 p ^ p+1' p+2 p+3 f q and N o b s e r v a t i o n s f o r each v a r i a b l e . The two s e t s of v a r i a b l e s form a random v e c t o r of o b s e r v a t i o n s , X. We choose a r e f e r e n c e system which makes EX = 0, wit h u n i t v a r i a n c e . I f the two s e t s are d e s i g n a t e d by X^^ and then X (1) (2) As X i s p a r t i t i o n e d i n t o v e c t o r s of p and q components the v a r i a n c e - c o v a r i a n c e m a t r i x i s a l s o p a r t i t i o n e d i n t o p and q rows and columns; X'X X ( D X ( 1 ) x ( 2 ) x ( l ) X ( D X ( 2 ) x ( 2 ) x ( 2 ) w i t h D = D l l °12 D 2 1 D 2 2 ; and the c o r r e l a t i o n m a t r i x i s R = R l l R12 R 2 1 R22 , i n which *D = R when mean = 0 and v a r i a n c e = 1. 1 2 1 . R = m a t r i x o f i n t e r c o r r e l a t i o n s o f p+q v a r i a b l e s , i n t e r c o r r -v a r i a t e s , R^^ = r c o r r e l a t i o n s among the p s o c i o e c o n o m i c R 22 = i n t e r c o r r e l a t i o n s among t h e q b e h a v i o r v a r i a t e s R^2 = i n t e r c o r r e l a t i o n s of s o c i o e c o n o m i c w i t h b e h a v i o r v a r i a t e s ; and R 2^ = t r a n s p o s e o f R ^ The c a n o n i c a l c o r r e l a t i o n p r o b l e m i s t o b r i n g o u t the n a t u r e o f t h e i n t e r d e p e n d e n c e o f t h e two s e t s o f v a r i a t e s when t h e l i n e a r c o m b i n a t i o n o f the two s e t s a r e m a x i m a l l y c o r -r e l a t e d . C o n s i d e r an a r b i t r a r y l i n e a r c o m b i n a t i o n U = a ' X ^ ^ o f t h e p s o c i o e c o n o m i c v a r i a t e s and an a r b i t r a r y l i n e a r combina-(2 ) t i o n V = y'X o f t h e q b e h a v i o r v a r i a t e s . The maximum c o r -r e l a t i o n i s found by r o t a t i n g t h e r e f e r e n c e axes f o r each s e t of v a r i a t e s i n t h e t e s t space so t h a t t h e axes o f t h e p v a r i a t e s e t and t h a t o f t h e q v a r i a t e s e t form a new axes system. I f th e p a r a m e t e r s a and y a r e n o r m a l i z e d such t h a t U and V have u n i t v a r i a n c e t h e n ; 2 (1) (1 ) 1 E U = 1 = E c x ' X v 'xK ' a , and 2 (2) (2 ) * E V = 1 = E y ' X v }XK ' y The c o r r e l a t i o n between U and V i s , t h e r e f o r e , E U V = E a * X ( 1 ) X ( 2 ) V (1 ) because E X ( 1 ) ' a = 0 and. E y ' X ( 2 ) = 0 . 1 2 2 . T h e r e b y , s u b s t i t u t i n g i n ( 1 ) , t h e c o r r e l a t i o n b e t w e e n t h e t w o s e t s i s EUV = a'R12y (2 ) T h e c a n o n i c a l c o r r e l a t i o n p r o b l e m i s t o f i n d t h e v a l u e s o f a a n d y w h e n £UV i s m a x i m i z e d , i . e . w h e n t h e d e r i v a -7 t i v e o f EUV w i t h r e s p e c t t o a a n d y i s z e r o . A n d e r s o n h a s s h o w n t h a t E u v i s m a x i m i z e d w h e n * ' A R 1 1 R 1 2 R 2 1 X R 2 2 a Y = 0 T h e d e t e r m i n a n t a l e q u a t i o n o f t h e f i r s t t e r m (3) R 2 2 R 2 1 R l l R 1 2 ~ X 1 = 0 (4) i s s o l v e d f o r a l l p o s s i b l e v a l u e s o f A ( u p t o t h e l e s s e r o f p o r q ) : t h e c h a r a c t e r i s t i c r o o t s . T h e c a n o n i c a l c o r r e l a t i o n , R , f o r e a c h r o o t i s w h i c h i s a m e a s u r e o f t h e d e g r e e t h a t c 1 o b s e r v a t i o n s r e f e r e n c e d b y t h e a x e s o f e a c h s e t o c c u p y t h e s a m e r e l a t i v e p o s i t i o n i n t h e r e s e a r c h s p a c e . * * F o r e a c h c h a r a c t e r i s t i c r o o t t h e v e c t o r s o f t h e c o e f f i c i e n t s a a n d y a r e f o u n d f o r t h e s e t U a n d V f r o m t h e c a n o n i c a l e q u a t i o n s * S e e A p p e n d i x F f o r d e r i v a t i o n . * * T h e s t a t i s t i c a l s i g n i f i c a n c e o f a n y r o o t A . a n d t h e r e f o r e t h e c a n o n i c a l c o r r e l a t i o n R c i s t h e C h i - s q u a r e 2 s t a t i s t i c , w h e r e X = - [ N - . 5 ( p + q + 1 ) ] I n A ' ; i n w h i c h A - S ( 1 - A . ) , ( s e e R e f . 6) i = r + l 1 ' 123 ( R 2 2 R21 R l ! R12 - XiX)y = ° ' a n d ( 5 ) a = (R^J R 1 2 Y ) / A 1 , (6) where a g i v e s the w e i g h t i n g of each of the socioeconomic v a r i a b l e s i n the in t e r d e p e n d e n t r e l a t i o n s h i p and y g i v e s the wei g h t i n g of each of the b e h a v i o r v a r i a b l e s i n the r e l a t i o n s h i p , To determine the r e l a t i o n s h i p between socioeconomic s t r u c t u r e and b e h a v i o r of the sample s e t we have 12 v a r i a b l e s which can be d i v i d e d i n t o the two component groups X^ "*"^  and X ^ i n which the X ^ s e t c o n s i s t s o f : X1 = age (AGE), X 2 = o c c u p a t i o n (OCC), X^ = car n e c e s s i t y f o r work (CNEC), X^ = c a r ownership (COWN), X,. = income (INC) , and Xg = a v a i l a b i l i t y of c a r (CARA). (2) S e t X v ' c o n s i s t s o f : * Xg = r e s i d e n t i a l t r a v e l time (TTO), X n = CBD t r a v e l time (TFRM), X10 = t o t a l t r a v e l time (OTT), X ^ = o u t - o f - p o c k e t expenses (OPE), *Xy the v a r i a b l e hour end was dropped from t h i s t e s t because of c o n c e p t u a l i n c o m p a t i b i l i t y and program l i m i t a t i o n s t h a t X ( 1 ) must be < X ( 2 ) . 1 2 4 . ; = o u t - o f - p o c k e t expenses -f income (E/INC) , and X13 = ^ U S f r e c 2 u e n c y (FREQ) . A c a n o n i c a l a n a l y s i s was made of the study data u s i n g program UBC BMD06M from the UBC l i b r a r y . Tables XVI and XVII show the r e s u l t s of the c a n o n i c a l a n a l y s i s f o r the auto group and the bus group r e s p e c t i v e l y . C a n o n i c a l c o r r e l a t i o n s are s i g n i f i c a n t , and t h e r e are two s i g n i f i c a n t r o o t s f o r each group. A comparison of the two groups on t h e i r socioeconomic-behavior interdependence i n d i c a t e s some important d i f f e r e n c e s . F i r s t , t h e r e i s a s t r o n g e r r e l a t i o n s h i p between socioeconomic s t r u c -t u r e and b e h a v i o r among the bus r i d i n g group than the c a r d r i v i n g group (R = .91 vs R c = .71) on the f i r s t c a n o n i c a l v a r i a t e s . T h i s i m p l i e s t h a t bus r i d e r s have the type of s o c i o -economic c o n s t r a i n t s which make them dependent upon the a t t r i -butes of the t r a n s p o r t a t i o n system, w h i l e c a r d r i v e r s have more freedom to choose d i f f e r e n t combinations of s e r v i c e a t t r i b u t e s and t h e r e f o r e are l e s s dependent upon the a t t r i b u t e s of the system. The c o r r e l a t i o n between the two s e t s of v a r i a b l e s denotes a s t a t e of e q u i l i b r i u m i n which d e c i s i o n s of c a r owner-s h i p , s p a t i a l l o c a t i o n , and mode c h o i c e are i n t e r d e p e n d e n t . I t supports the i d e a t h a t those who d r i v e c a r s , and t h e r e f o r e presumably of a high c a r ownership category, have a b e t t e r c h o i c e of r e s i d e n c e and job l o c a t i o n than those who are more dependent upon the t r a n s p o r t a t i o n s e r v i c e s . I t a l s o i m p l i e s t h a t c o n t r o l p o l i c i e s w i l l have a s m a l l e r l o c a t i o n a l e f f e c t on 1 2 5 . Table XVI CANONICAL CORRELATION TEST FOR CAR DRIVER GROUP FIRST CANONICAL VARIATE: R = . 7 1 c VARIABLES COEFFICIENTS VARIABLES COEFFICIENTS OF SET 1 (a) OF SET 2 (Y) X±(AGE) . 0 2 1 4 Xg(TTO) - . 0 5 4 3 x 2(OCC) . 0 0 6 5 X g(TFRM) - . 1 0 0 7 X 3(CNEC) . 0 7 5 8 X 1 Q(OTT) . 0 3 6 7 X4(COWN) - . 0 3 6 3 X i ; l(OPE) 1 . 6 8 2 9 X 5(INC) . 9 8 8 0 X 1 2(E/INC) - 1 . 7 6 6 6 X, (CARA) 6 . 1 6 1 7 X 1 3(FREQ) . 0 0 6 3 2 X TEST FOR SIGNIFICANCE OF ROOTS ROOT R c A. A 2 A * X d . f . P 1 0 . 7 1 4 9 0 . 5 0 4 1 0 . 4 7 3 4 9 2 5 . 8 8 36 < . 0 0 1 2 0 . 1 6 8 6 0 . 0 2 5 6 0 . 9 6 3 8 4 5 . 6 1 25 < . 0 1 3 0 . 0 8 7 3 0 . 0 0 7 6 0 . 9 8 9 3 1 3 . 3 5 16 n . s . SECOND CANONICAL VARIATE : R C = . 1 7 VARIABLES COEFFICIENTS VARIABLES COEFFICIENTS OF SET 1 (a) OF SET 2 (Y) X±(AGE) - . 5 5 9 1 Xg(TTO) - . 1 7 7 0 x 2(OCC) - . 2 4 8 1 X g(TFRM) . 2 4 9 9 X 3(CNEC) - . 4 5 1 2 X 1 Q(OTT) - . 1 2 0 6 X4(COWN) - . 5 5 2 6 X i ; l (OPE) . 0 8 3 5 X 5 (INC) . 1 8 9 3 X 1 2(E/INC) . 1 8 9 3 X, (CARA) o - 1 . 2 3 9 1 X 1 3(FREQ) . 9 7 4 0 126. Ta b l e XVII CANONICAL CORRELATION TEST FOR BUS GROUP FIRST 1 CANONICAL VARIATE: R c .91 VARIABLES COEFFICIENTS VARIABLES COEFFICIENTS OF SET 1 (a) OF SET 2 ( Y ) X^AGE) .0933 X g (TTO) .0168 x 2(OCC) -.0009 X n (TFRM) -.0344 X 3(CNEC) -.0000 X 1 Q(OTT) .0184 X4(COWN) -.0442 X l ; L(OPE) . 2974 X c(INC) o .9500 X 1 2(E/INC) -1.0485 Xr(CARA) 6 .0341 X 1 3(FREQ) .0200 2 X TEST FOR SIGNIFICANCE OF ROOTS ROOT R c X . A l 2 X d . f . P 1 0.9109 0. 8299 0.1275 1970.0 36 < .001 2 0.4865 0. 2372 0.7480 278.0 25 < .001 3 0.1264 0. 0159 0.9800 19.3 16 n. s . SECOND CANONICAL VARIATE: R .49 VARIABLES COEFFICIENTS VARIABLES COEFFICIENTS OF SET 1 (a) OF SET 2 (y) X X(AGE) .0892 Xg (TTO) .0083 x 2 ( o c c ) .0279 X g (TFRM) -.0662 X 3(CNEC) -.0000 X 1 Q(OTT) -.0998 X4(COWN) -1.8093 X i ; L(OPE) -1.2693 X 5(INC) .3940 X 1 2(E/INC) .0762 X,(CARA) 6 -2.1340 X 1 3 (FREQ) .9828 127. t h i s group than on the group who c u r r e n t l y use t r a n s i t . That i s , i f the d i s u t i l i t y of t r a v e l becomes unacceptable to t h i s group they may tend to change job or home l o c a t i o n to r e l i e v e the s i t u a t i o n r a t h e r than a d j u s t to a c o n t r o l l e d change i n the e x i s t i n g system. Secondly, i n both groups income and system c o s t f a c -t o r s are the prime components d e s c r i b i n g the i n t e r r e l a t i o n s h i p of socioeconomic s t r u c t u r e and b e h a v i o r . I t i s e v i d e n t however t h a t p a r k i n g charges (OPE f o r c a r d r i v e r s ) have much more i n f l u e n c e r e l a t i v e to the o t h e r system components f o r the c a r d r i v e r s than f a r e s do f o r t r a n s i t passengers (OPE f o r t r a n s i t g r o u p ) . Thus, h i g h incomes are a s s o c i a t e d w i t h h i g h o u t - o f -pocket expenses f o r both groups but f o r t r a n s i t r i d e r s t h i s i s more or l e s s f i x e d , m o d i f y i n g i t s e f f e c t . Income and c o s t m o d i f i e d by the a b i l i t y to pay (OPE/INC) shows a h i g h i n t e r -dependence i n both groups. However, the evidence i s weak be-cause of the s u b s t a n t i a l i n t e r c o r r e l a t i o n between income and o u t - o f - p o c k e t expenses d i v i d e d by income f o r the t r a n s i t group (r = -0.26 f o r c a r d r i v e r s , and r = -0.86 f o r bus passengers) (see T a b l e XVIII ) . While the f i r s t c a n o n i c a l v a r i a t e shows i n t e r d e p e n -dence of income and c o s t , the second c a n o n i c a l v a r i a t e b r i n g s out the p o s i t i v e r e l a t i o n s h i p s between the o t h e r socioeconomic c h a r a c t e r i s t i c s and bus frequency.. F o r both groups c a r a v a i l a -b i l i t y and bus frequency are r e l a t e d . T h i s can be e x p l a i n e d 1 2 8 . T a b l e X V I I I MATRIX OF SIMPLE INTERCORRELATIONS OF SOCIOECONOMIC AND BEHAVIOR VARIABLES FOR CAR GROUP AND TRANSIT GROUP X. x 2 x 3 x 4 x 5 CAR GROUP X;, X 8 X 9 X 1 0 X l l X 1 2 X 1 3 X, X. X, X r o 6 u CO X, X 1 0 X 1 1 X 1 2 X 1 3 , 3 0 - . 5 9 * 3 4 . 5 0 * * * _ . 2 5 * - . 4 3 * . 2 1 * . 3 3 - . 9 1 . 8 6 . 2 7 - . 8 6 - . 2 6 * * 3 5 2 3 - . 2 6 * - . 2 3 * 8 4 * 3 2 ,64 * * r < . 2 0 129. through the car ownership f a c t o r s i n c e low f r e q u e n c i e s would p r e c i p i t a t e h i g h e r c a r ownership, which i s brought out by a high i n t e r c o r r e l a t i o n of c a r ownership w i t h car a v a i l a b i l i t y (r = -0.91 f o r c a r group and r = -.86 f o r the bus group). The r e l a t i v e l y c l o s e l i n k between socioeconomic c h a r a c t e r i s t i c s and system performance f o r t r a n s i t r i d e r s has important r a m i f i c a t i o n s f o r CBD p a r k i n g p o l i c i e s . I f too r e s t r i c t i v e p r i c i n g or l o c a t i o n a l p l a n n i n g i s imposed i t c o u l d have the e f f e c t of d e c e n t r a l i z i n g automobile o r i e n t e d a c t i v i -t i e s . I f p a r k i n g c o s t s are taken as a b u s i n e s s overhead, e i t h e r d i r e c t l y or i n the form of the wage r a t e some f i r m s may f i n d i t economical to d e c e n t r a l i z e i f the d i s l o c a t i o n does not b r i n g o t h e r diseconomies. The f a c t t h a t fewer diseconomies would accrue t o c a r d r i v e r s , s i n c e they are l e s s dependent on the system, would tend to r e i n f o r c e d e c e n t r a l i z a t i o n of i n d u s t r i e s which had a p r o p o r t i o n a t e l y l a r g e number of automobile commuting employees. These may be the f r i n g e i n d u s t r i a l and warehousing f i r m s which employ a l a r g e number of craftsmen and l a b o u r e r s , a t y p i c a l c a r o r i e n t e d group. The a n a l y s i s a l s o appears to support a r e c i p r o c a l r e l a t i o n s h i p between c a r ownership and bus s e r v i c e . With the high c a r ownership r a t e o f the study area the e f f e c t i s prob-a b l y r e l a t e d to the m u l t i p l e commuter households of the West Vancouver apartment complex. The e x i s t e n c e of a good bus s e r -v i c e would d o u b t l e s s delay a number of non-family households 1 3 0 . ( s i n g l e people l i v i n g communally) from the purchase o f t h e i r f i r s t c a r , or the purchase o f a second c a r . CLASSIFICATION OF MODAL GROUPS BY COMBINED FACTORS The r e s e a r c h q u e s t i o n posed i s : can a combination of socioeconomic v a r i a b l e s and b e h a v i o r a l v a r i a b l e s s e r v e to d e f i n e the c l a s s i f i c a t i o n of the users of the c o r r i d o r system i n t o a group which d r i v e c a r s and a group which takes the bus to work, and i f so, what i s the r e l a t i v e i n f l u e n c e of b e h a v i o r a l v a r i a b -l e s to socioeconomic ones? M u l t i p l e d i s c r i m i n a n t a n a l y s i s i s used to t e s t the v a l i d i t y of the a p r i o r i c l a s s i f i c a t i o n of the two c l i e n t groups and to assess the r e l e v a n t dimensions of the c l a s s i f i -c a t o r y c r i t e r i a . A l i n e a r f u n c t i o n of t h a t s e t of v a r i a b l e s which d e f i n e the i n d i v i d u a l socioeconomic c h a r a c t e r i s t i c s and be h a v i o r p r o f i l e s i s found which b e s t d i s c r i m i n a t e s between the c l i e n t groups under study. The c o e f f i c i e n t s of the r e s u l -t a n t f u n c t i o n determine the degree to which t h e i r a s s o c i a t e d v a r i a b l e s adds to the d i s c r i m i n a t i o n between the c l i e n t groups. Some e x p l a n a t i o n of m u l t i p l e d i s c r i m i n a n t a n a l y s i s , i t s assumptions, and how i t i s used i n the p r e s e n t case i s i n or d e r . ( U n f o r t u n a t e l y the l i t e r a t u r e of t h i s technique i s r a t h e r w i d e l y s c a t t e r e d and fragmentary, w i t h few t r a n s p o r t a -t i o n or p l a n n i n g a p p l i c a t i o n s . T h e r e f o r e a b r i e f o u t l i n e of the technique i s c o n s i d e r e d r e l e v a n t ) . 131. An O u t l i n e of M u l t i p l e D i s c r i m i n a n t A n a l y s i s D i s c r i m i n a n t a n a l y s i s i s a s t a t i s t i c a l c r i t e r i o n f o r the c l a s s i f i c a t i o n of o b j e c t s or persons based on measurement of the dimensions or c h a r a c t e r i s t i c s of the o b j e c t s or persons g to be c l a s s i f i e d . I t was f i r s t developed by F i s h e r to c l a s s i f y a n t h r o p o l o g i c a l f i n d i n g s . The theory has been extended and 9 10 11 12 f u r t h e r documented by Rao K e n d a l l , Anderson, Rulon e t a l 13 14 and Hope. Cooley and Lohnes have a l s o p r e s e n t e d the t e c h -nique w i t h computational procedures. The technique i s meant to answer the q u e s t i o n : g i v e n o b s e r v a t i o n s on v a r i a b l e s which r e p r e s e n t i n d i v i d u a l measurements ( c h a r a c t e r i s t i c s and scores e t c . ) , to what group i s t h a t i n d i -v i d u a l most l i k e l y to be a member. L i k e m u l t i p l e l i n e a r r e g r e s -s i o n a n a l y s i s d i s c r i m i n a n t a n a l y s i s seeks to f i n d the l i n e a r f u n c t i o n which i n some way d e s c r i b e s the "best f i t " w i t h r e f e r -ence to m u l t i p l e o b s e r v a t i o n s . The l i n e of "best f i t " may a l s o reduce the dimensions of the problem, seeking to d e s c r i b e i n fewer dimensions the essence o f the r e l a t i o n s h i p . D i s c r i m i n a n t a n a l y s i s s t a r t s w i t h a p r i o r i c l u s t e r s which are e i t h e r p e r c e i v e d to be n a t u r a l or d e f i n e d t h e o r e t i -c a l l y , and f i n d s t h a t c h a r a c t e r i s t i c which b e s t d i s c r i m i n a t e s between the c l a s s e s . Assumptions of the technique are t h a t the c l a s s e s are mutually e x c l u s i v e and e x h a u s t i v e , t h a t the d i s t r i b u t i o n of the v a r i a t e s are m u l t i v a r i a t e normal, and t h a t 132. the v a r i a n c e of each c l a s s i s homogeneous, making the d i s p e r -s i o n m a t r i c e s equal f o r each c l a s s . * A p p l i c a t i o n of d i s c r i m i n a n t a n a l y s i s to the problem of mode c h o i c e i s by the s o - c a l l e d d i s c r i m i n a t i o n - c l a s s i f i c a -t i o n model. The d i s c r i m i n a t i o n model i s designed to t e s t hypotheses about mode group membership. I t i s a procedure to s e l e c t an o p t i m a l boundary which d i v i d e s the t e s t space, d e f i n e d by a s e t of v a r i a b l e s , i n t o two r e g i o n s . C l a s s i f i c a t i o n i s a procedure f o r d e c i d i n g which mode a new i n d i v i d u a l i s l i k e l y to choose. I t i s based on the assignment of a new i n d i v i d u a l to a p a r t i c u l a r mode based on a measure of the l i n e a r r e l a -t i o n s h i p among the a t t r i b u t e s of the modal system. An O u t l i n e o f the D i s c r i m i n a n t Model Co n s i d e r two modal groups w i t h p measurements on each i n d i v i d u a l d e s c r i b i n g a v e c t o r X, c o n s i s t i n g of o b s e r v a t i o n s on the system a t t r i b u t e s of X^,X^,X^,...,X^. The o b s e r v a t i o n X's have two types of v a r i a n c e s , (1) t h a t between each group and (2) t h a t w i t h i n each group. The c r i t e r i o n f o r d i s c r i m i n a t i o n i s t h a t the r a t i o of the square of the d i f f e r e n c e s of means of the o b s e r v a t i o n s on the two mode groups to the common v a r i a n c e of each mode group (pooled w i t h i n group v a r i a n c e ) i s maximized. That i s to maximize: *This i s the assumption of h o m o s c e d a s t i c i t y . 133 [ E v . ( X i : L - X . 2 ) ] 2 G = where, P P E E v. v . D . . i j 1 3 ± J p = number of v a r i a t e s , v = weights or c o e f f i c i e n t s t o be determined, D = pooled w i t h i n group v a r i a n c e - c o v a r i a n c e , or d e v i a t i o n , m a t r i x , and X 1 ' X 2 = m e a n s °^ the v a r i a t e s f o r the two modal groups. 9G D i f f e r e n t i a t i n g w i t h r e s p e c t to v^and making = 0, we have: P P p S E V i V j D i j I V ± i = < X i l " x i 2 ) 3 E v . ( X i l - X i 2 ) l P i - j * _ _ where v. a = E D J ~ x , 2 ^ ' o r i n v e c t o r n o t a t i o n , -* i v = D (X-^  - X 2) when a s u i t a b l e (7) co n s t a n t i s s e l e c t e d . The v e c t o r of weights v are c o e f f i c i e n t s which l o c a t e the means of the groups from a new, transformed a x i s system on the c r i t e r i o n t h a t the new a x i s system i s r o t a t e d by an angle 6 from the t e s t a x i s system i n such a way t h a t the d i s t a n c e between the means when p r o j e c t e d onto the new a x i s i s maximized.** * n D i s the i n v e r s e of D... • 13 **See appendix G f o r a geometric d e s c r i p t i o n of the a x i s r o t a t i o n and the v e c t o r v. 1 3 4 . The g e n e r a l i z a t i o n of t h i s two group case to more than two groups i s made by r e p l a c i n g • the v e c t o r of the d i f -f e r e n c e s of means of the two groups by the v e c t o r of the d i f f e r e n c e s between the grand mean ( i . e . the mean f o r a l l groups combined) and the v e c t o r of group means, each taken i n t u r n and weighted by group s i z e . T h i s i s normally expres-sed i n m a t r i x a l g e b r a to f a c i l i t a t e the computational aspects of the te c h n i q u e . Two pth order m a t r i c e s d e f i n e the d i s c r i -minant c r i t e r i o n : an A matrix (the between group sum of squares and c r o s s products m a t r i x whose elements comprise the c r o s s products of d e v i a t i o n of the group mean from the grand mean), and the W or e r r o r m a t r i x whose elements are the w i t h i n group d i s p e r s i o n s , and i s a pooled e s t i m a t e of i n d i v i d u a l o b s e r v a t i o n s from the group mean. A t h i r d m a t r i x , T, i s the t o t a l sum of squares and c r o s s products of d e v i a t i o n from the grand means.* Thus the A m a t r i x i s c a l c u l a t e d from A = T - W, and the d i s c r i m i n a n t c r i t e r i o n i s to maximize A/W. The d i s c r i m i n a n t f u n c t i o n s are a s s o c i a t e d w i t h the *The elements of A, W, and T are d e f i n e d as f o l l o w s : g _ a. . = I N (X., - X. ) (X .. - X .) , i j k = 1 g i k 1' jk 3 " g N g N t. . = E ( X . „ - X . ) ( X . _ , - X . ) , where ID n = 1 i - n 2. jn j g - number of groups Ng = number of s u b j e c t s i n group g (cont'd) 135, d e t e r m i n a n t a l e q u a t i o n : | W - A l | = 0. (8) The s c a l a r W '''A i s maximized when the o r i g i n a l t e s t a x i e s i s r o t a t e d through the angle 0 so t h a t the matrix e q u a t i o n i s [W - 1A - AI]v = 0, (9) e x p r e s s i n g the weights v f o r maximum d i s c r i m i n a t i o n f o r each A p o s s i b l e . The c r i t e r i o n f o r d i s c r i m i n a t i o n then becomes: v!Av. A. = — r n — i i n which (10) l l v. i s the t r a n s f o r m a t i o n m a t r i x of the d i r e c t i o n c o s i n e s o f 8. l That is-, v, i s a v e c t o r whose elements r e p r e s e n t the angles between the o r i g i n a l (or t e s t axis) f o r each v a r i a t e and the d i s c r i m i n a t o r . The d i s c r i m i n a n t problem i s to f i n d the v e c t o r of weights v^ a s s o c i a t e d w i t h the maximum v a l u e of A^ f o r any r o o t . Taking the p a r t i a l d e r i v a t i v e of (10) and s e t t i n g i t equal to zero g i v e s : N = t o t a l number of s u b j e c t s , and i and j run from 1 to p, where p = number of v a r i a b l e s , X i k ' i R j k = means of v a r i a t e i and j f o r group k, X.,X. = mean of v a r i a t e i and j f o r a l l groups combined, X., ,X., = n s c o r e v a l u e on v a r i a t e i (j) f o r group i k n jkn k / a n d X. , X. = n*"*1 s c o r e v a l u e on v a r i a t e i ( j ) . i n jn J 1 3 6 . 3 A . 2 [ ( v . W v . ) A v . - ( v f A v . ) W v . ] 1 _ 1 1 l i i l 3 v . . . . . . . . 2 l ( v ! W v . ) l l = 0 w h i c h s i m p l i f i e s t o [ W - 1 A - A i I ] v i = 0 . ( 1 2 ) T h e r e l a t i v e s i z e o f A ' s i n d i c a t e t h e e x t e n t t o w h i c h t h e a s s o c i a t e d d i s c r i m i n a n t f u n c t i o n d i s t i n g u i s h e s b e t w e e n t h e g r o u p s , a n d t h e v e c t o r v ^ i s t h e v e c t o r o f c o e f f i c i e n t s w h i c h m a x i m i z e s t h e d i f f e r e n c e b e t w e e n g r o u p s . A s m a n y v e c t o r s a s n e c e s s a r y t o a c c o u n t f o r s u c c e s s i v e b e t w e e n g r o u p v a r i a n c e a r e e x t r a c t e d u p t o t h e n u m b e r o f v a r i a t e s o r o n e l e s s t h a n t h e n u m b e r o f g r o u p s . T h i s f o r m o f t h e a n a l y s i s i s u s e f u l t o t e s t h y p o -t h e s e s a b o u t i n t e r g r o u p d i f f e r e n c e s i n t h e m e a s u r e d v a r i a t e s . * * G r o u p d i f f e r e n c e i s d e f i n e d b y a s e r i e s o f s i g n i -f i c a n c e t e s t s . W i l k ' s l a m b d a c r i t e r i o n i s u s e d t o e s t i m a t e t h e d i s c r i m i n a t i n g p o w e r o f t h e t e s t a n d i s d e r i v e d a s a f u n c -t i o n o f t h e r o o t s o f W ~ X A ( i . e . A ^ ) a s f o l l o w s : r 1 A = n [-Yin—^ ' r = n u m b e r o f r o o t s . i = l " L + A i T h i s i s c o n v e r t e d t o t h e f a m i l i a r F - t e s t b y t h e f o l l o w i n g t r a n s f o r m a t i o n : 1 / s „ 2 r , 1 - A ' x , m s + 2 A \ . , F m s + 2 A = ( A l / s > ( — 2 T ) ' i n w h l G h s = V ( P ^ 2 ~ 4 ) / ( p 2 + q 2 - 5) , p = n u m b e r o f v a r i a t e s , m = n - ( p + q + l ) / 2 , q = g - 1 , g = n u m b e r o f g r o u p s A = - ( p q - 2 ) / 4 , • n = N - l r = p q / 2 . . c ^ ( c o n t ' d ) 137. I f the between group v a r i a n c e i s s i g n i f i c a n t l y g r e a t e r than the pooled w i t h i n group v a r i a n c e s as i n f e r r e d from a g e n e r a l -i z e d v a r i a n c e r a t i o , or F - t e s t , we conclude t h a t there i s some s e t of v a r i a t e s on which these two groups can be c o n s i d e r e d d i f f e r e n t . The v e c t o r of c o e f f i c i e n t s , r e f e r r e d to as e i g e n -v e c t o r s d e f i n e the r e l e v a n t dimensions ( i n terms of the v a r i -a b l e s chosen to r e p r e s e n t the d i f f e r e n c e s ) which maximized t h i s d i f f e r e n c e . The eigenvector,: when s c a l e d by m u l t i p l y i n g each element w i t h the square r o o t of the d i a g o n a l elements of the W m a t r i x g i v e s the r e l a t i v e c o n t r i b u t i o n s o f each of the v a r i a t e s to the d i s c r i m i n a t i o n . 2 An a l t e r n a t e t e s t of A i n terms of x c a n be used: X 2 = -[N - .5(p+q+l)] i n A' where g A ' = n (1 - A . ) i = r + l 2 A s t a t i s t i c , Mahalanobis D , i s used to t e s t the s i g n i f i c a n c e of group s e p a r a t i o n i n the reduced space. The s t a t i s t i c i s to t e s t the n u l l h y p o t h e s i s t h a t the d i f f e r e n c e i n means are zero. Rao x5 and K i n g l 6 g i v e : 2 P P i i D , E E s J d . d . ab • - i • i I T i = l ]=1 J where d. = X. - X.^, the d i f f e r e n c e i n the two group c e r i t r o i d s on v a r i a t e i , d. = X - X. , f o r ( i , j = l , 2 , . . . , p ) , s l j = (s. . ) _ 1 , s. . = (S. ( a ) + s f b ) )/(N + N. - 2) . 13 13 13 13 ' a b 2 D can a l s o be converted t o the F - r a t i o by the f o l l o w i n g : N N, - p-1 N N, 0 p (N aN b)(N_N B-2) U a b ' with p and (N N, -p-1) degrees of freedom, a ]D The f a m i l i a r squared m u l t i p l e c o r r e l a t i o n c o e f f i c i e n t can a l s o be found where': D2 _ A JA — 1+A * 138. When the t e s t a x i s i s r o t a t e d through the angle 0 the o r i g i n a l t e s t v a r i a t e s are p r o j e c t e d p e r p e n d i c u l a r l y to the new a x i s , and the o r i g i n a l t e s t v a l u e s are .transformed to s o - c a l l e d d i s c r i m i n a n t " s c o r e s " w i t h one l e s s dimension than the o r i g i n a l v a l u e s . For the case of two modes and two v a r i a t e s the two dimensional space i s reduced to a s t r a i g h t l i n e and the d i s c r i m i n a n t s c o r e i s the l o c a t i o n of an i n d i v i -d u a l along the l i n e . T h i s i s shown i n the g e o m e t r i c a l i n t e r -p r e t a t i o n of the two group-two v a r i a t e case as F i g u r e 6, where A and B are the "swarm" of o b s e r v a t i o n s on the v a r i a t e s X^ and X„ and X,. and X_. are the group means. 2. A D The o r i g i n a l t e s t swarm d e s c r i b e an e q u i - p r o b a b i l i t y e l l i p s e i n the t e s t space which reduces to a c i r c l e , as p r o j e c -t e d , when the a x i s i s r o t a t e d to maximize the between to w i t h i n group v a r i a n c e . The l i n e j o i n i n g the p r o j e c t e d means, or p a r a l -l e l t o i t i s the c a n o n i c a l v a r i a t e , and f o r the two group case, i s synonomous with the d i s c r i m i n a t o r . Rulon has shown t h a t the l i n e p a s s i n g through the i n t e r s e c t i o n of any two c o n c e n t r i c e l l i p s e s minimizes the o v e r l a p of the two swarms on the d i s c r i -m inator, which i s p e r p e n d i c u l a r t o t h i s l i n e . I f t h e r e are more than two groups t h e r e are (g-1) or p c a n o n i c a l v a r i a t e s , and the f i r s t c a n o n i c a l v a r i a t e minimizes the sum of the squared d e v i a -t i o n s from the p r o j e c t e d group means. 1 3 9 . X, FIGURE 6 ROTATION OF AXIS TO MAXIMIZE BETWEEN TO WITHIN GROUP VARIANCE FOR OBSERVATION CLUSTERS A AND B - GEOMETRIC ILLUSTRATION OF TWO GROUP TWO VARIATE CASE 140. An O u t l i n e of the C l a s s i f i c a t i o n Model Besides t e s t i n g hypotheses about i n t e r g r o u p d i s t a n -17 ces and r e l e v a n t dimensions of e x p l a n a t o r y v a r i a b l e s , the technique i s used as a mathematical model to a s s i g n new i n d i -v i d u a l s to some c l a s s based on a s e t of e x p l a n a t o r y v a r i a b l e s which i n some way c h a r a c t e r i z e the person or s u b j e c t being c l a s s i f i e d . The a p p l i c a t i o n s of the technique to modal s p l i t through the work of Warner and Quarmby have emphasized d i s -c r i m i n a n t a n a l y s i s as an assignment r u l e . D i s c r i m i n a n t f u n c -t i o n s are used i n a p r e d i c t i v e model of mode c h o i c e i n which the e x p l a n a t o r y v a r i a b l e s are used to p r e d i c t the p r o b a b i l i t y of c h o i c e . I t i s c onvenient to d e r i v e l i n e a r d i s c r i m i n a n t f u n c t i o n s f o r each group i n the a n a l y s i s , r a t h e r than a s i n g l e d i s c r i m i n a t o r which serves to s e p a r a t e the groups as above. The l i n e a r d i s c r i m i n a n t f u n c t i o n f o r a s e t of obser-v a t i o n s on X., i = l , 2 , . . . , p takes the form: i n which v i s the v e c t o r of weights d e r i v e d by (7). By s u b s t i -t u t i o n of (7) the l i n e a r d i s c r i m i n a n t f u n c t i o n becomes + or P E v.X. I I * v i i -E E D (X . , - X. 0) X. , . . l l i 2 l i j 141. or i n v e c t o r n o t a t i o n X'D ^"(X^ - X^) • The d i s c r i m i n a n t f u n c -t i o n can be e v a l u a t e d f o r any i n d i v i d u a l on h i s v e c t o r of o b s e r v a t i o n s , X, and a d i s c r i m i n a n t " s c o r e " determined. The d i s c r i m i n a n t r u l e d e s c r i b e s a boundary, and i f an i n d i v i d u a l ' s s c o r e i s on one s i d e o f the boundary he i s l i k e l y , w i t h some p r o b a b i l i t y , to be a member of one mode group, otherwise he i s thought t o be a member of the oth e r mode. P r e d i c t i o n thus i n v o l v e s c a l c u l a t i n g a v a l u e f o r each commuter and a s s i g n i n g him some p r o b a b i l i t y of choosing one mode over the oth e r on the b a s i s of t h i s v a l u e . Consider two modal p o p u l a t i o n s normally d i s t r i b u t e d , one a s s o c i a t e d w i t h one s e t of ex p l a n a t o r y v a r i a b l e s , and the second w i t h another s e t . The t o t a l t e s t space may be thus d i v i d e d i n t o two r e g i o n s i n which one r e g i o n (say R^) c o n s i s t s of t h a t area of the t e s t space where the d e n s i t y of observa-t i o n s f o r modal p o p u l a t i o n one i s a maximum, and a l l o t h e r o b s e r v a t i o n s f a l l i n t o another r e g i o n (say R^). L e t q be the a p r i o r i p r o b a b i l i t y t h a t an o b s e r v a t i o n i s from mode p o p u l a t i o n 1 and (1-q) the a p r i o r i p r o b a b i l i t y t h a t an o b s e r v a t i o n i s from mode p o p u l a t i o n 2. I f an i n d i v i d u a l i s drawn from a mixed popu-l a t i o n which c o n t a i n s the p r o b a b i l i t y r a t i o of q / ( l - q ) of modal p o p u l a t i o n one to modal p o p u l a t i o n two, the p r o b a b i l i t y of wrongly c l a s s i f y i n g an i n d i v i d u a l s e l e c t e d a t random i s q + (1-q)* and the r u l e which minimizes the p r o b a b i l i t y of *That i s , i f the chance of wrongly c l a s s i f y i n g an i n d i v i d u a l of the f i r s t group i s equal to the chance of wrongly c l a s s i f y i n g an i n d i v i d u a l of the second group. I f the chances of wrongly c l a s s i f y i n g i n d i v i d u a l s of t h e i r r e s p e c t i v e groups are ct^ and a ^ t t h i s e x p r e s s i o n becomes a-^q + a 2 ( l - q ) . wrongly c l a s s i f y i n g the i n d i v i d u a l i s the r e l e v a n t c l a s s i f i -•4. • 18 c a t o r y c r i t e r i o n . I f f 1 ( X ) and f 2 ( X ) a r e t h e p r o b a b i l i t y d e n s i t i e s of mode p o p u l a t i o n one and two r e s p e c t i v e l y where X i s the v e c t o r of e x p l a n a t o r y v a r i a b l e s , the two r e g i o n s of the t e s t space are those i n which: R^ i s d e f i n e d as: q f ^ > (1-q) R 2 i s d e f i n e d as: (1-q) f' 2 > q f ^ The d i s c r i m i n a n t r u l e used to c l a s s i f y an i n d i v i d u a l i s as f o l l o w s . I f f 1 ( x ) / f 2 ( x ) > k c l a s s i f y the i n d i v i d u a l as be l o n g i n g to r e g i o n 1; otherwise c l a s s i f y him as be l o n g i n g to r e g i o n 2. The consta n t , k, there f o r e d e f i n e s a boundary, on one s i d e of which the i n d i v i d u a l belongs to one mode and the other s i d e of which he belongs to an a l t e r n a t i v e mode. This i s a b i n a r y c h o i c e problem and assumes t h a t only two modes are c o n s i d e r e d . The d i s c r i m i n a n t r u l e c l a s s i f i e s an i n d i v i d u a l by the method of maximum l i k e l i h o o d . S i n c e f^(X) and f^{X) are assumed j o i n t - n o r m a l the r a t i o f i ( X ) ^ e - ^ 2 ' * - 5 ! ' ' " " 1 ' * - * ! ' ) 1 _ 2TT f 2 ( x ) i - g / 2 ( x - x 2 ) ' D 1 ( X - X 2 ) ] 2TT 1 4 3 . a n d I n f . ( x ) I n f „ ( x ) T h e d i s c r i m i n a n t r u l e w i l l a s s i g n a n i n d i v i d u a l t o m o d e 1 i f w h e r e X-^ a n d X^ a r e t h e b e s t e s t i m a t e s o f t h e m e a n s o f m o d a l p o p u l a t i o n o n e a n d t w o r e s p e c t i v e l y , a n d D ^ i s t h e i n v e r s e o f t h e ( a s s u m e d ) c o m m o n d i s p e r s i o n - m a t r i x o f e a c h o f t h e m o d e p o p u l a t i o n s . T h e s e c o n d h a l f o f t h e a b o v e e x p r e s s i o n i s a c o n s t a n t a n d t h e f u n c t i o n c a n t h e r e f o r e b e w r i t t e n l i k e l i h o o d o f a n i n d i v i d u a l c h o o s i n g a n y m o d e ( s a y m o d e 1) o f t w o a l t e r n a t i v e s , b a s e d o n h i s d i s c r i m i n a n t s c o r e d e r i v e d f r o m v a l u i n g t h e d i s c r i m i n a n t f u n c t i o n f o r b o t h m o d a l g r o u p s . T h u s , t h e c o n d i t i o n a l p r o b a b i l i t y t h a t a n o b s e r v a t i o n a t X i s f r o m m o d e 1 i s I n > I n k X ' D {X1 - X 2 ) - a A p r o b a b i l i t y m o d e l c a n b e d e v e l o p e d t o e s t i m a t e t h e P(X) q f 1 ( X ) q f 1 ( X ) + ( l - q ) f 2 ( X ) 144 . By t a k i n g n a t u r a l l o g a r i t h m s of both s i d e s and combining c o n s t a n t s i n t o one c o n s t a n t , c, and u s i n g c o n v e n t i o n a l nota-t i o n f o r d i s c r i m i n a n t s c o r e s , z, i t can be shown t h a t : z p(X) = — - , i n which 1 + e Z z = X , D _ 1 ( X 1 - X ) - c T h i s r e l a t i o n s h i p i s an S-shaped l o g i s t i c curve. The z-value f o r each i n d i v i d u a l can be found from the expres-s i o n with the degree of d i s c r i m i n a t i o n dependent upon the range of z - v a l u e s . The z-value d i c t a t e s p r o b a b i l i t i e s between 0 and 1, of an i n d i v i d u a l w i t h t h a t z-value of choosing each mode. The i n d i v i d u a l i s then a s s i g n e d to the mode which g i v e s him the h i g h e s t p r o b a b i l i t y . T e s t of the model i s d e f i n e d by the num-ber of m i s c l a s s i f i c a t i o n s when known i n d i v i d u a l s are a s s i g n e d to mode groups on the b a s i s of t h e i r p o s t e r i o r p r o b a b i l i t i e s . I f the number of m i s c l a s s i f i c a t i o n s are s u f f i c i e n t l y s m a l l the model may be used as a p r e d i c t i v e one. Group D i s c r i m i n a t i o n on Combined V a r i a b l e s A v e r s i o n of the Cooley Lohnes computer program (DISCRIM),* m o d i f i e d by the author f o r data tape i n p u t and converted to FORTRAN IV, was used to t e s t the a p r i o r i mode c l a s s i f i c a t i o n on the combined demand v a r i a b l e s . Group means *The program DISCRIM i s documented i n : W i l l i a m W. Cooley and P a u l R. Lohnes, M u l t i v a r i a t e Procedures f o r the  B e h a v i o r a l S c i e n c e s , John W i l e y , New York: 1962, p.127. The author i s i n d e b t e d to Nirmala d e v i Cherukupalle f o r her c a r d deck of the o r i g i n a l program, as w e l l as her program f o r the Mahalanobis D 2 t e s t . 1 4 5 . and s t a n d a r d d e v i a t i o n s a r e shown on T a b l e XIX. The a b s o l u t e v a l u e o f the means have l i t t l e r e l e v a n c e s i n c e they a r e s t a n d a r -d i z e d , b u t the t r a n s f o r m e d means a l l o w some i n s i g h t i n t o t h e d i f f e r e n c e between g r o u p s . F o r example, the n e c e s s i t y t o have a c a r f o r work, c a r o w n e r s h i p , income, r e s i d e n t i a l t r a v e l t i m e , and o u t - o f - p o c k e t expenses a r e s u f f i c i e n t l y d i f f e r e n t from the o v e r a l l mean o f z e r o , and w i t h s u b s t a n t i a l d i f f e r e n c e between means, t h a t one would e x p e c t t h e s e v a r i a b l e s t o be i m p o r t a n t i n group s e p a r a t i o n . Moreover, t h e r e l a t i v e v a l u e s o f t h e means can be used t o f u r t h e r s u p p o r t t h i s h y p o t h e s i s . T a b l e XX i s a summary o f the s t a t i s t i c a l t e s t s o f the d i s c r i m i n a t i o n h y p o t h e s i s . U n i v a r i a t e F t e s t s on t h e 13 v a r i a b l e s show t h a t a l l a r e s i g n i f i c a n t a t p < . 0 5 . A l l b u t CBD t r a v e l t i m e a r e s i g n i f i c a n t a t p < . 0 0 1 . The r e s u l t o f t h e t e s t o f the n u l l h y p o t h e s i s o f no d i s c r i m i n a t i o n produces a v a r i a n c e r a t i o F „ 0 o f 5 0 4 . 6 9 and an e x t r a c t e d r o o t s i g n i f i c a n t rl z. 2 a t p < . 0 0 1 , as d e t e r m i n e d by t h e X t e s t . T a b l e XXI g i v e s t h e s e p a r a t i o n o f the group c e n t r o i d s i n t h e r e d u c e d ( d i s c r i m i -2 nant) space w i t h a M a h a l a n o b i s D o f 1 . 9 9 r e s u l t i n g i n an v a r i a n c e r a t i o (F) o f 8 3 . 0 , w h i c h i s s i g n i f i c a n t a t p < . 0 0 1 . 2 The R s t a t i s t i c , o r s t r e n g t h o f d i s c r i m i n a t i o n has been shown, and may be i n t e r p r e t e d i n the same way as the c o e f f i c i e n t o f d e t e r m i n a t i o n used i n r e g r e s s i o n a n a l y s i s . * The v a l u e o f . 7 5 0 denotes s t r o n g d i s c r i m i n a t i o n between the two modal g r o u p s . *That i s , t h e p e r c e n t o f v a r i a t i o n i n t h e d a t a w h i c h i s e x p l a i n e d by t h e s t a t i s t i c a l t e s t , and i s n u m e r i c a l l y A 1 + A " Table XIX GROUP MEANS AND STANDARD DEVIATIONS OF MODAL GROUPS FOR COMBINED SOCIOECONOMIC AND PERFORMANCE VARIABLES (STANDARD SCORES i . e . X = 0.0 S = 1.0) VARIABLE CAR BUS DRIVERS PASSENGERS GROUP MEANS x l (AGE) .147 -.190 X2 (OCC) -.230 .300 X3 (CNEC) .720 -.930 X4 (COWN) .356 -.458 X5 (INC) .415 -.534 X6 (CARA) .336 -.421 X7 (HREND) -.144 .190 X8 (TTO) -.601 .773 X9 (TFRM) -.047 .060 X10 (OTT) -.294 .378 X l l (OPE) -.241 .310 X12 (E/INC) -.417 .540 X13 (FREQ) .094 -.121 GROUP STANDARD DEVIAT. Xl (AGE) 1.022 1.217 x2 (OCC) .883 1.101 x 3 (CNEC) .826 .016 x 4 (COWN) 1.153 .947 X5 (INC) .916 .960 x6 (CARA) .733 .990 x 7 (HREND) 1.032 .900 x8 (TTO) .681 .910 X 9 (TFRM) 1.182 .777 x10 (OTT) .970 .909 x i i (OPE) 1.388 .338 X12 (E/INC) . 852 .915 x13 (FREQ) 1.148 .758 T a b l e XX S T A T I S T I C A L TESTS OF S I G N I F I C A N C E FOR DISCRIMINATION OF MODES ON COMBINED SOCIOECONOMIC AND PERFORMANCE VARIABLES UNIVARIATE F-TEST VARIABLE F-RATIO p X1 (AGE) 49 . . 8 7 < . 0 0 1 x 2 (OCC) 1 5 5 . . 1 8 . 0 0 1 X 3 (CNEC) 3 8 4 0 . . 3 7 <, . 0 0 1 X 4 (COWN) 3 1 5 . . 9 9 < . . 0 0 1 X 5 (INC) 5 5 9 . . 3 0 . 0 0 1 X, (CARA) 6 4 2 6 . . 9 5 < . . 0 0 1 X ? (HREND) 6 3 . . 7 0 . 0 0 1 Xg (TTO) 1 6 4 8 . , 8 4 < , . 0 0 1 X g (TFRM) 5 . . 9 1 . 0 5 X 1 Q(OTT) 2 7 5 . . 7 8 < , . 0 0 1 X I ; L(OPE) 1 4 5 . . 8 3 . 0 0 1 X 1 2(E/INC) 6 4 2 . . 8 8 < . . 0 0 1 X 1 3(FREQ) 2 5 , . 5 0 . 0 0 1 TEST OF DISCRIMINATORS A = .2509 F„„ = 504.69 F, = 2r - 13 F < .001 1 P F 2 = ms + 2X = 2197 R2 = .750 TEST OF ROOT: ? 2 Number of Root % Root No. of Sum of d . f . X X Roots (^.) i s of Roots Roots P i T r ace Summed 1 2.9863 100.0 13 2.9863 13 13,200 <.001 1 4 8 . T a b l e XXI CENTROIDS OF MODAL GROUPS IN REDUCED SPACE AND SIGNIFICANCE TEST OF GROUP SEPARATION ON COMBINED SOCIOECONOMIC AND PERFORMANCE VARIABLES GROUP CENTROID CAR DRIVERS 0 . 9 9 1 8 BUS PASSENGERS - 1 . 2 7 8 1 TEST OF GROUP SEPARATION D 2 = 1 . 9 9 2 6 1 3 F 2 1 9 7 -- ' 8 3 . 0 0 F P < . 0 0 1 I n t e r p r e t a t i o n of D i s c r i m i n a n t L o a d i n g The i n t e r p r e t a t i o n o f t h e t e s t i s by the v e c t o r l o a d i n g s o r the v a l u e s o f the v c o e f f i c i e n t s . The c o e f f i c i e n t s a r e s c a l e d i n the t e s t t o g i v e the r e l a t i v e v a l u e o f t h e l o a d i n g f o r each a t t r i b u t e . The v e c t o r l o a d i n g s show a h i g h degree o f dominance o f s o c i o e c o n o m i c f a c t o r s f o r t h e a u t o d r i v e r g r o u p , and a dominance o f b e h a v i o r a l ones f o r t h e t r a n -s i t group (Table X X I I ) . The i n t e n s i t y o f the need f o r a c a r a t work i s the major c o n t r i b u t o r t o i t s use f o r the j o u r n e y t o work as w e l l as h o u s e h o l d c a r ow n e r s h i p and income o f the com-muter. These f i n d i n g s g e n e r a l l y s u p p o r t t h e l i t e r a t u r e , a l t h o u g h 149 . Table XXII DISCRIMINATOR VECTOR LOADINGS ON COMBINED SOCIOECONOMIC AND PERFORMANCE VARIABLES VARIABLE SCALED VECTOR LOADING* X 1(AGE) 0.34 x 2 (OCC) -1.31 X 3(CNEC) 21.53 X4(COWN) 6. 29 X 5(INC) 3.75 X g(CARA) -4.76 X 7 (HREND) -3.62 Xg(TTO) -18.16 Xg(TFRM) 6.23 X 1 Q(OTT) -6.25 X x l(OPE) 1.63 X 1 2(E/INC) -6.43 X 1 3(FREQ) 6.86 *The d i s c r i m i n a t o r v e c t o r , v, i s s c a l e d by m u l t i p l y i n g i t by the square r o o t of the d i a g o n a l elements of the W m a t r i x . Thus, the r e l a t i v e c o n t r i b u t i o n of each v a r i a b l e to the d i s c r i m i n a t o r i s shown. the r e l a t i v e l y s m a l l c o n t r i b u t i o n of income i s s u r p r i s i n g . T h i s may be due t o a r e l a t i v e homogeneity of income i n the study a r e a . But i t a l s o may show the r e l a t i v e l y s m a l l e f f e c t of i n -come on c h o i c e due to system f a c t o r s . Zupan i n h i s study of the New York r e g i o n concluded t h a t income was a f a c t o r i n 150 . whether the mode c h o i c e d e c i s i o n was p r i m a r i l y based on e n v i r o n -mental f a c t o r s ( " v a r i a b l e s t h a t measure the c h a r a c t e r i s t i c s of the home and work l o c a t i o n s " ) or on those f a c t o r s which measured the c h a r a c t e r i s t i c s of the t r a n s p o r t a t i o n system. Low income groups were more s u s c e p t i b l e to environmental f a c -19 t o r s and h i g h income groups to t r a n s p o r t a t i o n system f a c t o r s . I t may be t h a t the e f f e c t of income here i s d i s s i p a t e d through-out the b e h a v i o r a l f a c t o r s by i t s c o r r e l a t i o n w i t h e n v i r o n -mental f a c t o r s , s i n c e income i s h i g h l y c o r r e l a t e d w i t h c a r a v a i l a b i l i t y (r = .93) and a l s o w i t h the o u t - o f - p o c k e t expenses to income r a t i o (r = .64) (Table X X I I I ) . Income i s seen to be much more important when i t s e f f e c t alone i s c o n s i d e r e d as shown by i t s u n i v a r i a t e F r a t i o , a f a c t which a l s o i n f e r s t h a t when a l l v a r i a b l e s are c o n s i d e r e d as a system the income e f f e c t i s d i s t r i b u t e d through other v a r i a b l e s . B e h a v i o r a l f a c t o r s a s s o c i a t e d w i t h the c a r d r i v e r group i n c l u d e CBD t r a v e l time and bus frequency i n the r e s i d e n -t i a l zone. The r e l a t i v e l y l a r g e c o n t r i b u t i o n of CBD t r a v e l time i s s u r p r i s i n g s i n c e u n i v a r i a t e measures do not show i t to be important, nor i s i t i n t e r c o r r e l a t e d w i t h o t h e r v a r i a b l e s . I t does show t h a t when the combined system i s c o n s i d e r e d CBD t r a v e l time i s a f a c t o r i n c l a s s i f y i n g auto d r i v e r s s e p a r a t e l y from t r a n s i t r i d e r s . The e f f e c t i s probably due to the very s h o r t walking d i s t a n c e s of about 17 p e r c e n t of a l l c a r d r i v e r s (see T a b l e XIV). The c o n t r i b u t i o n of bus frequency i s as expected s i n c e the frequency of buses a v a i l a b l e to auto d r i v e r s i s one 1 5 1 . Table XXIII CORRELATION MATRIX OF COMBINED SOCIOECONOMIC AND PERFORMANCE VARIABLES X l X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 1 0 X l l X 1 2 X l x 1 1 . 0 0 x 2 * 1 . 0 0 X 3 * - . 2 5 1 . 0 0 X 4 * * . 3 5 1 . 0 0 X c . 3 1 - . 5 5 . 4 4 . 2 4 1 . 0 0 X^ . 3 2 - . 5 4 . 4 0 * . 9 3 1 . 0 0 6 X ? * * * * * * 1 . 0 0 X 0 * * - . 5 2 - . 2 3 - . 3 3 - . 2 8 * 1 . 0 0 o X * * * * * * * * 1 . 0 0 9 X 1 Q * * - . 2 7 * * * . 3 8 . 3 0 * 1 . 0 0 X ^ * * * * * * * * * * 1 . 0 0 X 1 2 - . 2 6 . 3 8 - . 4 1 * - . 6 4 - . 7 0 * . 3 4 * . 2 4 . 6 7 1 . 0 0 x * * * * * * * * * . 2 3 * * 1 . 0 * = r < . 2 0 minute l e s s than t h a t to bus passengers, with means of 17.6 and 16.6 minutes r e s p e c t i v e l y . The major c o n t r i b u t i o n to t h i s d i f f e r e n c e occurs i n the remote \\/estern p a r t of West Vancouver where auto use i s h i g h r e l a t i v e t o t r a n s i t use and bus f r e -quencies are very low. B e h a v i o r a l f a c t o r s mainly c o n t r i b u t e to the s e p a r a t i o n of t r a n s i t r i d e r s . R e s i d e n t i a l t r a v e l time i s the primary one, and r e p r e s e n t s the very g r e a t d i f f e r e n c e between the almost n e g l i g i b l e time to get to a c a r to s t a r t the journey compared to the time d i s t a n c e to the bus s t o p . The r e s i d e n t i a l t r a v e l time does not i n c l u d e w a i t i n g time a t the bus stop nor t r a n s f e r time which are c o n s i d e r e d by the author to be d i f f e r e n t i n concept from w a l k i n g time to the bus s t o p , and are u n i q u e l y a p a r t of t r a n s i t use w i t h no comparative d i s u t i l i t i e s i n the c a r mode. I f these were i n c l u d e d the e f f e c t of r e s i d e n t i a l t r a v e l time would be more prominant. O v e r a l l t r a v e l time i s a l s o an important c o n s i d e r a t i o n i n s e p a r a t i n g car d r i v e r s from t r a n s i t passengers, and shows the e f f e c t of the g r e a t e r t r a v e l times f o r the l a t t e r group. The r a t i o of expenses to income a l s o c o n t r i b u t e s h e a v i l y to the s e p a r a t i o n of the t r a n s i t group. T h i s might be expected where t r a n s i t passengers, even those w i t h a c h o i c e as d e f i n e d here by having come from a house-h o l d w i t h a t l e a s t one c a r , are r e l a t i v e l y s e n s i t i v e t o c o s t f a c t o r s , e s p e c i a l l y when i t i s r e l a t e d to t h e i r a b i l i t y to pay. E x i s t i n g p a r k i n g charges show onl y s m a l l e f f e c t s i n s e p a r a t i n g 153. auto d r i v e r s , probably because of the c o m p a r a t i v e l y low r a t e s i n Vancouver, and the number of auto d r i v e r s who enjoy f r e e p a r k i n g . The time of a r r i v a l a t the d e s t i n a t i o n has some i n f l u e n c e f o r t r a n s i t r i d e r s as h y p o t h e s i z e d . The a v a i l a b i l i t y of a c a r a l s o c o n t r i b u t e s to s e p a r a t i o n of the t r a n s i t group. However, t h i s was found to be h i g h l y c o r r e l a t e d w i t h income (r = 0.91) . ' MODE CHOICE AS A FUNCTION OF POLICY VARIABLES Loadings on P o l i c y D i s c r i m i n a t o r Only those v a r i a b l e s amenable to p a r k i n g p o l i c y were t e s t e d to determine the e f f e c t s s e p a r a t e from s t r u c t u r a l i n -f l u e n c e s , because the e f f e c t s of p o l i c y are c e n t r a l t o t h i s i n v e s t i g a t i o n and a l s o because of s u b s t a n t i a l i n t e r c o r r e l a t i o n s between some v a r i a b l e s w i t h i n the socioeconomic s e t of v a r i -a b l e s . For example, income and c a r a v a i l a b i l i t y are h i g h l y i n t e r c o r r e l a t e d w i t h s m a l l e r but s u b s t a n t i a l i n t e r c o r r e l a t i o n of o c c u p a t i o n and income and o c c u p a t i o n and c a r a v a i l a b i l i t y , and between c a r necessary f o r work and these v a r i a b l e s . More-over, very s u b s t a n t i a l i n t e r c o r r e l a t i o n e x i s t s between income and c a r a v a i l a b i l i t y and c o s t f a c t o r s and between car necessary, income and r e s i d e n t i a l t r a v e l time (Table X X I I I ) . Group means of the v a r i a b l e s show s u b s t a n t i a l d i f -f e r e n c e s i n r e s i d e n t i a l t r a v e l time, although bus passengers have a mean walking d i s t a n c e of l e s s than 3 minutes (Table XXIV. Table XXIV GROUP MEANS AND STANDARD DEVIATIONS FOR MODAL GROUPS ON POLICY VARIABLES (RAW SCORES) VARIABLE CAR BUS DRIVERS PASSENGERS Xg (TTO) 1.332 2.760 X_ (TFRM). y 3 .058 3 .196 X 1 Q(OTT) 31.278 37.399 X I ; L(OPE) .488 .622 X 1 2(E/INC) .173 .369 X 1 3(FREQ) 17.588 16.634 GROUP STANDARD DEVIATIONS X g (TTO) .707 .946 X g (TFRM) 1.534 1.009 X 1 Q(OTT) 8.832 8.284 X N (OPE) .436 .106 X 1 2(E/INC) .175 .188 X 1 3(FREQ) 5.079 3 .354 Approximately 6 minutes s e p a r a t e the bus group from the car group. About one minute i n bus frequency separates the two groups. The r e l a t i v e l y s m a l l spread between these means, as a percentage of the t o t a l t r a v e l time and frequency i n d i c a t e s t h a t i f these v a r i a b l e s are c r i t i c a l l y important i n the c h o i c e of mode, r e l a t i v e l y s m a l l decreases are needed so t h a t the s e r v i c e by bus i s equal to t h a t by c a r . T h i s has i m p l i c a t i o n s 155. f o r mode s h i f t to be d i s c u s s e d l a t e r . The s i g n i f i c a n c e t e s t s i n Table XXV show t h a t d i s c r i -2 m i n a t i o n i s w e l l d e f i n e d , with an R of .530. However, a r e -d i s t r i b u t i o n of the c o n t r i b u t o r y f a c t o r s takes p l a c e when the s t r u c t u r a l e f f e c t s are removed. The v e c t o r l o a d i n g s emphasize the c o n t r i b u t i o n of b e h a v i o r a l v a r i a b l e s f o r the t r a n s i t group, r a n k i n g 1,2,3 i n o r d e r of magnitude (Table XXVI). The new l o a d i n g s d r a m a t i c a l l y r e - e n f o r c e the e f f e c t s of the r a t i o of expenses to income and o v e r a l l t r a v e l time, as w e l l as the r e s i d e n t i a l t r a v e l time i n f l u e n c e . L i k e w i s e , zonal bus f r e -q u e n c i e s , CBD t r a v e l time and p a r k i n g charge i n c r e a s e i n impor-tance. The l a r g e s t i n c r e a s e s i n i n f l u e n c e by e l i m i n a t i n g the s t r u c t u r a l e f f e c t s i s i n the c o s t f a c t o r s , p a r k i n g charges f o r auto d r i v e r s , f a r e s , and the expenses over income proxy. T h i s r e s u l t appears to i n f e r t h a t p a r k i n g charge and t r a n s i t f a r e changes would be more e f f e c t i v e f o r a homogeneous p o p u l a t i o n , w h i l e these f a c t o r s decrease i n o v e r a l l importance when the v a r i a b i l i t y of s t r u c t u r a l c h a r a c t e r i s t i c s i s c o n s i d e r e d . T h i s means t h a t these e f f e c t s w i l l have more impact on some s o c i o -economic groups than o t h e r s . Modal Group Assignment by P o l i c y D i s c r i m i n a t o r To p r e d i c t mode s p l i t , and to s i m u l a t e the r e s u l t s on mode s p l i t of changes i n p o l i c y i t i s necessary t o determine the v a l i d i t y - o f the p o l i c y d i s c r i m i n a t o r i n p r e d i c t i o n . A stepwise d i s c r i m i n a n t t e s t was performed by a UBC r e v i s e d e d i t i o n 1 5 6 . Table XXV STATISTICAL TESTS OF SIGNIFICANCE FOR DISCRIMINATION OF MODES ON SIX POLICY VARIABLES UNIVARIATE F-TEST VARIABLE F-RATIO p Xg(TTO) 1648. 84 <.001 Xg(TFRM) 5. 91 < .05 X 1 Q(OTT) 275. 78 <.001 X I ; L(OPE) 145. 83 <.001 X 1 2(E/INC) 642. 88 <.001 X 1 3(FREQ) 25. 50 <.001 TEST OF POLICY DISCRIMINATORS A = .46801 FH2 417.55 F, = 2r - 6 F < .001 1 P F = 2 ms + 2X = 2204 R2 = .530 TEST OF ROOT No. of Root % Root No. of Sum of Roots ^. i s of Roots Roots d . f . X X l T r ace Summed P 1 1.1367 100.0 6 1.1367 6 4950 <.001 157 . T able XXVI VECTOR LOADINGS ON POLICY DISCRIMINATOR USING SIX VARIABLES VARIABLE SCALED VECTOR 28.91 7.43 11.42 4.79 17.67 10.32 of the BMD07M program. T h i s program performs a m u l t i p l e d i s -c r i m i n a n t a n a l y s i s i n a stepwise manner i n which a t each s t e p one v a r i a b l e i s e n t e r e d i n t o the s e t of d i s c r i m i n a t i n g v a r i a b l e s a c c o r d i n g t o i t s F v a l u e . A v a r i a b l e i s d e l e t e d i f i t s F v a l u e become too low. The c r i t e r i o n s e t f o r e n t e r i n g and d e l e t i n g a v a r i a b l e i s F < .05. P The f i r s t run was made on a l l 6 v a r i a b l e s i n c l u d e d i n the p o l i c y d i s c r i m i n a t o r . The r e s u l t s showed a l l 6 accounted f o r s i g n i f i c a n t v a r i a t i o n i n the s e p a r a t i o n of the two groups. However, some c o r r e l a t i o n e x i s t e d between the o u t - o f - p o c k e t expense v a r i a b l e and t h a t measuring o u t - o f - p o c k e t expenses d i v i d e d by income ( i . e . X ^ w i t h X ^ ) . T h e r e f o r e o u t - o f - p o c k e t expense v a r i a b l e (X-^) was removed s i n c e i t c o n t r i b u t e s very l i t t l e to the s e p a r a t i o n of the'two groups. The r e s u l t i n g X g (TTO) X. (TFRM) 9 X 1 Q(OTT) X u ( O P E ) X 1 2(E/INC) X,, (FREQ) 158. d i s c r i m i n a n t f u n c t i o n s f o r the car group and bus group r e s -p e c t i v e l y which were used to c a l c u l a t e the d i s c r i m i n a n t scores f o r each case a r e : z = -14.675 + 1.132X 0 + 1.695X n + 0.284X, n + 0.998X,„ c 8 9 10 12 + 0.773X 1 3 z. = -20.009 + 3.208X o + 1.431X_ + 0.35lX, n + 6.732X,„ b 8 9 10 12 + 0.659X 1 3 These f u n c t i o n s used to v a l u e each o b s e r v a t i o n a t X^ .. r e s u l t e d i n a z s c o r e f o r each i n d i v i d u a l , and t h i s s c o r e was used to determine the p o s t e r i o r p r o b a b i l i t y o f group membership by means of the assignment model o u t l i n e d above. The p o s t e r i o r a s s i g n -ment of a l l i n d i v i d u a l r e s u l t e d i n a 12.6 p e r c e n t m i s c l a s s i f i -c a t i o n (Table XXVII). T h i s i s a measure of the e f f e c t i v e n e s s of the model to c l a s s i f y i n d i v i d u a l i n t o modes based on the p o l i c y d i s c r i m i n a t o r . Another measure of the goodness of o v e r a l l f i t of the d i s c r i m i n a t o r i s the c a n o n i c a l c o r r e l a t i o n , R , i n the reduced space. A f i r s t c a n o n i c a l v a r i a t e , synonomous with the d i s c r i m i n a t o r i n the two group case, i s the l i n e o f c l o s e s t f i t to the means of the groups on the v a r i a t e s i n the reduced space, and i s f i t t e d i n such a way t h a t the sum of d e v i a t i o n s of the group means from the l i n e i s a minimum. The c a n o n i c a l c o r r e l a t i o n c o e f f i c i e n t i s a measure of the goodness of f i t of the l i n e and i n t h i s case R = .73. The " f i t " can a l s o c be g i v e n by the more f a m i l i a r square of the m u l t i p l e c o r r e l a t i o n 2 2 c o e f f i c i e n t , R , and i n t h i s case r e s u l t e d i n R = .535. 159. Table XXVII PREDICTED CLASSIFICATION VERSUS ACTUAL MODE USED FOR F IVE SIGNIFICANT POLICY VARIABLES* NUMBER PREDICTED MISCLASSI-TO BE IN GROUP FICATIONS . CAR BUS TOTAL ACTUAL CAR 1134 110 1244 110 NUMBER I N GROUP BUS 168 799 967 168 2211 278* •Percent misses 278/2211 = 12.6% TEST OF SIGNIFICANCE OF FIVE•POLICY VARIABLES F u 0 = 4 9 6 . 8 5 F < .001 P R = .73 c R 2 = .535 COMPARATIVE ANALYSIS OF RESULTS Comparison w i t h S i m i l a r S t u d i e s There are three known s t u d i e s s i m i l a r to t h i s a n a l y s i s which uses the d i s c r i m i n a t i o n - c l a s s i f i c a t i o n technique on s i m i l a r i n s t r u m e n t a l v a r i a b l e s . * .These are, Quarmby, Warner *A f o u r t h a n a l y s i s by M c G i l l i v a r y c o n t a i n s no com-p a r a b l e t e s t s i n the p u b l i s h e d v e r s i o n of h i s paper. 160. and Bock's i n v e s t i g a t i o n s . Table XXVIII shows the v a r i a b l e s 2 t e s t e d f o r car versus t r a n s i t samples i n each study, the R , and p o s t e r i o r m i s c l a s s i f i c a t i o n s compared wi t h the p r e s e n t s tudy. T a b l e XXVIII COMPARISON OF RESULTS OF DISCRIMINANT-CLASSIFICATION ANALYSIS OF MODE CHOICE FOR CAR AND TRANSIT SAMPLES WITH THREE PREVIOUS STUDIES VARIABLES TESTED R PERCENT POSTERIOR MISCLASSI-FICATION QUARMBY (Sample S i z e = 542) TRAVEL TIME DIFFERENCE EXCESS TIME DIFFERENCE COST DIFFERENCE 523 23 .6 WARNER (Sample S i z e - 931) In COST RATIOS In TIME RATIOS CAR AVAILABILITY SEX 167 38.0 BOCK (Sample S i z e - 470) TIME DIFFERENCE COST DIFFERENCE CAR OWN. X TIME DIFF, INCOME X TIME DIFF. INCOME X COST DIFF. 207* 30.9 BROWN (Sample S i z e - 2211) RES. TRAVEL TIME CBD TRAVEL TIME TOTAL TRAVEL TIME OPE/INCOME BUS FREQUENCY 535 12.6 *R c a l c u l a t e d by the author from Bock's p u b l i s h e d r e s u l t s of F r a t i o and D 2. 161. Quarmby's b e s t r e s u l t s of s e v e r a l t e s t s u s i n g v a r i a b l e r a t i o s , d i f f e r e n c e s and logs of r a t i o s were f o r the d i f f e r e n c e measurement as reproduced here. He a l s o t e s t e d s e v e r a l a d d i t i o n a l v a r i a b l e s from those shown here i n c l u d i n g cost/income, use of c a r f o r work, ownership of car by f i r m , and a v a r i a b l e he named c a r demand r a t i o (number of d r i v e r s l i c e n c e s i n household to number of c a r s ) . The e x t e n s i o n of h i s t h r e e " d i f f e r e n c e " v a r i a b l e s by these a d d i t i o n a l ones 2 produced the same R v a l u e . Warner's comparable t e s t u s i n g auto t r a f f i c and c i t y mass t r a n s i t ( i t i s not c l e a r whether subway t r i p s are i n c l u d e d i n t h i s c a t e g o r y ) , u s i n g n a t u r a l l o g a r i t h m s of time and c o s t r a t i o s , car a v a i l a b i l i t y , and sex, produces a r e l a t i v e l y , s m a l l 2 R , although i t was s i g n i f i c a n t beyond the .01 l e v e l . He a t t r i b u t e s the r e l a t i v e l y s m a l l v a l u e ( i n comparison w i t h l e a s t squares problems) as r e s u l t i n g from i n d i v i d u a l data i n s t e a d of aggregated averages and from the unsystematic i n f l u e n c e s i n the n ature of the problem. Bock's r e s u l t s are between Quarmby's and Warner's u s i n g time and c o s t d i f f e r e n c e s and i n c l u d i n g m o d i f i c a t i o n s of those by c a r ownership and income measures. The r e s u l t s of the p r e s e n t study compares f a v o u r a b l y w i t h Quarmby's a n a l y s i s (with which i t i s the most s i m i l a r ) . The r e s u l t s produce a s l i g h t l y b e t t e r d i s c r i m i n a t i o n on the 162. c a n o n i c a l v a r i a t e as w e l l as fewer m i s c l a s s i f i c a t i o n on the p o s t e r i o r assignment. Two s i g n i f i c a n t c o n c l u s i o n s emerge from the compari-son of these a n a l y s e s . F i r s t , the p r e s e n t study d i f f e r s from the o t h e r s i n t h a t v a r i a b l e s are measured i n a b s o l u t e terms w i t h no r e f e r e n c e to the a l t e r n a t i v e s e r v i c e l e v e l s . T h i s i n f e r s t h a t a n a l y s i s can be accomplished w i t h o u t a d i r e c t measure of c o m p e t i t i v e s e r v i c e s f o r each i n d i v i d u a l . T h i s i s important i n terms of data c o l l e c t i o n , r e d u c i n g the survey to measurements of a c t u a l t r a v e l b e h a v i o r , without the n e c e s s i t y to measure o b j e c t i v e l y the a l t e r n a t i v e s e r v i c e (a d i f f i c u l t task s i n c e the p e r c e i v e d a l t e r n a t i v e s may not be obvious) or to determine them s u b j e c t i v e l y (an e q u a l l y d i f f i c u l t problem). Secondly, the r e s u l t s tend t o p o i n t to the v a l i d i t y of c o n s i d e r i n g micro-l e v e l p o l i c y v a r i a b l e s i n the a n a l y s i s . Quarmby has done t h i s w i t h h i s excess t r a v e l time d i f f e r e n c e s (walk and w a i t i n g t i m e s ) , and they have been f u r t h e r s u b d i v i d e d i n the p r e s e n t a n a l y s i s to r e s i d e n t i a l walk time and CBD walk time. The j u s t i f i c a t i o n f o r t h i s r e s t s on the f a c t t h a t these are of importance s e p a r a -t e l y s i n c e r e s i d e n t i a l t r a v e l time i s the major i n f l u e n c e i n mode c h o i c e b e h a v i o r w h i l e CBD t r a v e l time has a minor i n f l u e n c e . The s e p a r a t e i n f l u e n c e of these v a r i a b l e s have major i m p l i c a t i o n s f o r p o l i c y d e s i g n . 1 6 3 . PRINCIPAL FINDINGS The a n a l y s i s has demonstrated t h a t each modal group can be co n c e i v e d to occupy a unique socioeconomic space, which depends upon the type of t r a n s p o r t a t i o n s e r v i c e a v a i l a b l e , and which i n t u r n i s dependent upon the s e r v i c e which e x i s t s . For the c a r group t h e r e i s a s t r o n g interdependency between income and the c o s t of p a r k i n g , w i t h a secondary interdependency b e t -ween age and car ownership w i t h frequency of bus s e r v i c e . T h e r e f o r e , changes i n p a r k i n g c o s t would be expected to i n f l u e n c e d i f f e r e n t income groups d i f f e r e n t l y w i t h lower income groups b e i n g a f f e c t e d i n such a way t h a t they would e i t h e r s h i f t mode or to r e l o c a t e home or jo b . A l s o changes i n bus frequency may a f f e c t f u t u r e c a r ownership, i n t h a t f o r example, a commuter w i t h one c a r used f o r work may de c i d e t o r e l i n q u i s h i t to the f a m i l y f o r oth e r uses i f a bus w i t h s a t i s f a c t o r y frequency was a v a i l a b l e . Income and f a r e s are a l s o i n t e r d e p e n d e n t i n f l u e n c e s f o r t r a n s i t r i d e r s . T h i s interdependency between income and c o s t i s s t r o n g e r than t h a t f o r c a r d r i v e r s . T h i s i s probably due to the g e n e r a l l y lower incomes of t r a n s i t r i d e r s and t h e r e -f o r e i n c r e a s e d s e n s i t i v e n e s s to c o s t o f t r a v e l . Car ownership and a v a i l a b i l i t y are l i n k e d a l s o w i t h f a r e s and bus frequency and show the same i n f l u e n c e s as observed i n the car group, but f o r t r a n s i t r i d e r s these f a c t o r s weigh more h e a v i l y than f o r the more a f f l u e n t c a r d r i v e r s . 1 6 4 . F a c t o r s r e l a t i n g to socioeconomic s t r u c t u r e and the performance of the t r a n s p o r t a t i o n sys.tem a c t i n g i n c o n c e r t d i s c r i m i n a t e the users of one mode from the users of the oth e r mode. Among the combined f a c t o r s the n e c e s s i t y of a c a r a t work i s predominant f o l l o w e d by r e s i d e n t i a l t r a v e l time. The need to have a c a r a t the workplace has been c i t e d by many i n v e s t i g a t o r s to be a major f a c t o r i n the d e c i s i o n to d r i v e the c a r to work. While t h i s i s s e l f e v i d e n t , t h e r e are severe d i f f i c u l t i e s i n i n t e r p r e t i n g what t h i s means. No o b j e c t i v e measure of t h i s n e c e s s i t y has been made, w i t h a l l r e s u l t s of t e s t on the v a r i a b l e r e l a t e d t o the s u b j e c t i v e e v a l u a t i o n of the need f o r a c a r a t work. The survey upon which t h i s a n a l y s i s i s based attempts to s c a l e the degree of n e c e s s i t y of a c a r f o r work. In t h i s manner, the frequency w i t h which a c a r i s f e l t t o be needed shows up as a prime i n d i c a t o r ; t h a t as the frequency i n c r e a s e s the use of the car i n c r e a s e s . U n l i k e most s t u d i e s of socioeconomic i n f l u e n c e s on mode s p l i t , income and c a r owner-s h i p do not appear to be important. T h i s may be e x p l a i n e d by the high income, h i g h c a r ownership r a t e s of the sample, and i n f e r s t h a t one does not need to be a " c a p t i v e " r i d e r b e f o r e u s i n g the bus. The a n a l y s i s of the d i s c r i m i n a t o r of p o l i c y v a r i a b l e s has shown t h a t f i v e v a r i a b l e s w i l l s u c c e s s f u l l y reproduce mode c h o i c e b e h a v i o r . The most important of these are r e s i d e n t i a l t r a v e l time, o v e r a l l t r a v e l time, o u t - o f - p o c k e t expenses/ income and bus frequency. The walking time a t the CBD has not 1 6 5 . s h o w n t h e i n f l u e n c e s e x p e c t e d . T h e a n a l y s i s s u b s t a n t i a t e s t h e h y p o t h e s i s t h a t t h e s y s t e m f a c t o r s a r e t h e s i g n i f i c a n t o n e s i n t h e i r i n f l u e n c e o n m o d e s p l i t b e h a v i o r . CHAPTER V PROPENSITY OF CAR DRIVERS TO SHIFT MODE Mode S p l i t P l a n n i n g O b j e c t i v e s The p l a n n i n g o b j e c t i v e i s to study means of c r e a t i n g a modal s p l i t which w i l l h e l p achieve p u b l i c g o a l s . In p r a c -t i c e t h i s i n v o l v e s the p r e d i c t i o n of mode s p l i t based on user p r e f e r e n c e s and subsequent b e h a v i o r , and the development of the means to study changes i n b e h a v i o r on the system t o conform to e x t e r n a l l y pre-determined, but f l e x i b l e , ' s o c i e t a l o b j e c t i v e s . Presumably one such o b j e c t i v e c o u l d be t o r a t i o n a l i z e the flows on the t r a n s p o r t a t i o n system so t h a t p u b l i c o b j e c t i v e s c o u l d be met, w h i l e a t the same time meet as much as p o s s i b l e , i n d i -v i d u a l user p r e f e r e n c e s . A m a n i f e s t a t i o n of t h i s i s t h a t some car d r i v e r s are encouraged t o s h i f t to some oth e r mode, or combination o f modes.* T h i s means of r a t i o n a l i z i n g mode bal a n c e i n f e r s t h a t e i t h e r a multimodal system, or a pure t r a n s i t system i s f e a s i b l e and c o u l d i n c r e a s e s o c i a l w e l f a r e w h i l e a t the same time p r o v i d e users w i t h no more t o t a l d i s u t i l i t y of t r a v e l than p e r c e i v e d * I t i s a l s o p o s s i b l e t h a t a v a l i d o b j e c t i v e may be to s h i f t the demand from non-remunerative passenger t r a n s i t systems to automobiles. Homburger suggests t h a t B r i t a i n may i n f a c t be p u r s u i n g i m p l i c i t l y such a p o l i c y by abandoning unremunerative bus and r a i l s e r v i c e s w h i l e i n c r e a s i n g f a r e s , w h i l e a t the same time c a r r y i n g out a p o l i c y of i n c r e a s e d f r e e -way c o n s t r u c t i o n (see Ref. 1). 167 . b e n e f i t s of t r a v e l , and p r e f e r a b l y to ac h i e v e a lower l e v e l of i n d i v i d u a l d i s u t i l i t y . I t i s p o s t u l a t e d t h a t t h e r e i s some l e v e l of t r a n s p o r t a t i o n s e r v i c e a t which c a r commuters w i t h p a r t i c u l a r p r e f e r e n c e p a t t e r n s w i l l s h i f t to a new system because the p e r c e i v e d d i s u t i l i t y on the new system w i l l e qual o r drop below t h a t of d r i v i n g a c a r . The m a n i p u l a t i o n of the d i s u t i l i t i e s of the system can be accomplished i n 3 ways: (1) i n c r e a s i n g the d i s u t i l i t y of d r i v i n g , a c a r ' w h i l e the a l t e r n a t i v e remains the same, (2) d e c r e a s i n g the d i s u t i l i t y of the a l t e r n a t i v e w h i l e l e a v i n g the c a r a l t e r n a t i v e the same, and (3) a d j u s t both. The degree t h a t (1) w i l l have on dec-r e a s i n g i n d i v i d u a l w e l f a r e w i l l depend upon the s u r p l u s of b e n e f i t s over d i s u t i l i t y (or g e n e r a l i z e d cost) of t r a v e l . A l a r g e consumer s u r p l u s w i l l a l l o w s u b s t a n t i a l i n c r e a s e s i n g e n e r a l i z e d c o s t b e f o r e b e n e f i t s are exceeded. I f g e n e r a l i z e d c o s t exceeds b e n e f i t s w i t h i n c r e a s e i n d i s u t i l i t y a commuter would s h i f t t o t r a n s i t as long as some consumer s u r p l u s remains wi t h t h i s a l t e r n a t i v e , otherwise he would forego t r a v e l or leave the system by changing the s p a t i a l r e l a t i o n s h i p of home and job, thus d e c r e a s i n g system demand. One way to study these f o r c e s i s by way of an exten-s i o n of the a n a l y s i s of the p r e v i o u s c h a p t e r : b e h a v i o r on the system i s observed i n c o n j u n c t i o n w i t h a s e t of ex p l a n a t o r y v a r i a b l e s which i n some way are a s s o c i a t e d w i t h the c h o i c e o f mode. I d e a l l y , t h i s would be extended w i t h mode c h o i c e and system b e h a v i o r a n a l y s e d through d i f f e r e n t time p e r i o d s and 1 6 8 . e x t r a p o l a t e d as a p r e d i c t i o n of mode c h o i c e based on s i m u l a t e d changes i n the p r e d i c t i v e model. Some of the problems of t h i s approach have been d i s c u s s e d . An a l t e r n a t i v e method i s to q u e s t i o n commuters on the system about changes which would be necessary to have them s h i f t mode. I f they would change mode a t a l l they would do so onl y i f a system c o u l d be d e v i s e d which would p r o v i d e them with a t l e a s t the same or l e s s d i s -u t i l i t y than c u r r e n t l y e x p e r i e n c e d . I t remains on l y to observe how many commuters would s h i f t under a s p e c i f i c change i n system components, and the socioeconomic c h a r a c t e r i s t i c s of these commuters to p r e d i c t mode s p l i t , and the modal popu-l a t i o n s t r u c t u r e . However, f u l l y a c c u r a t e p r e d i c t i o n i s onl y p o s s i b l e i f the i n d i v i d u a l s who s a i d they would s h i f t mode under c e r t a i n c o n d i t i o n s a c t u a l l y do so i f those c o n d i t i o n s are met. Given the e x i s t i n g s t a t e of the a r t and minimal understanding of the r e l a t i o n s h i p between statements measuring p r e f e r e n c e p a t -t e r n s and subsequent b e h a v i o r the most we can a s s e r t i s t h a t any i n d i v i d u a l w i l l have some tendency or p r e d i s p o s i t i o n to a c t i n accordance w i t h h i s s t a t e d p r e f e r e n c e s . T h e r e f o r e , the model which d e s c r i b e s the p r o b a b i l i t y t h a t an i n d i v i d u a l w i l l s h i f t to a new modal system should more a c c u r a t e l y be viewed i n terms of p r o p e n s i t y to s h i f t r a t h e r than i n a p r e d i c t i v e sense. For t h i s reason the a n a l y s i s to f o l l o w i s i n terms of p r o p e n s i t y to s h i f t from c a r mode to a new modal system,whether i t i s a multimodal or pure t r a n s i t system. 1 6 9 . O u t l i n e o f t h e S h i f t P r o p e n s i t y M o d e l I t i s h y p o t h e s i z e d t h a t e a c h u s e r c h o o s e s t h a t m o d e w h i c h h e p e r c e i v e s t o h a v e t h e l e a s t d i s u t i l i t y o f a l l m o d e s a v a i l a b l e t o h i m . A l s o i t i s p o s t u l a t e d t h a t h i s p e r c e p t i o n o f a m o d e i s i n t e r m s o f i t s i n t r i n s i c c h a r a c t e r i s t i c s , o r a t t r i b u t e s , a n d n o t o f i t s i n s t i t u t i o n a l i z e d c h a r a c t e r i s t i c s . T h a t i s , t h e m o d e c h o i c e i s b a s e d o n p e r c e i v e d p e r f o r m a n c e c h a r a c t e r i s t i c s o f t h e s y s t e m , a n d n o t b e c a u s e o f a n a m e o r i t s i n s t i t u t i o n a l c o n n o t a t i o n s . I f w e f u r t h e r a s s u m e t h a t t h e t o t a l d i s u t i l i t y o f a m o d e i s l i n e a r a n d a n a d d i t i v e f u n c t i o n o f i t s a t t r i b u t e s a s p e r c e i v e d b y a n y u s e r , k , w e c a n s t a t e t h a t t h e d e c i s i o n t o t a k e a p a r t i c u l a r m o d e i s b e c a u s e < U ^ 2 w h e r e : = t o t a l d i s u t i l i t y o f a c c e p t e d m o d e ( i . e . m o d e 1) 2 U, = t o t a l d i s u t i l i t y o f r e j e c t e d m o d e ( i . e . m o d e 2) B u t e a c h m o d e i s a n a b s t r a c t i o n o f s o m e c o m b i n a t i o n o f m o d a l a t t r i b u t e s s o t h a t , p 1 p 2 E U. . < E U. , w h e r e : 1=1 1 ' K i = i 1 ' K U.^ k = d i s u t i l i t y o f a t t r i b u t e i f o r m o d e j a s p e r -' c e i v e d b y u s e r k , a n d p = t o t a l n u m b e r o f a t t r i b u t e s c o n s i d e r e d i n t h e c h o i c e d e c i s i o n . 1 7 0 . E a c h d i s u t i l i t y t e r m U . " 1 , c a n b e c o n c e i v e d t o c o n s i s t o f t w o 1 , K c o m p o n e n t s : t h a t w h i c h i s a v a r i a b l e m e a s u r e o f t h e a t t r i b u t e , a n d a p a r a m e t e r w h i c h w e i g h s t h a t a t t r i b u t e i n r e l a t i o n t o a l l o t h e r a t t r i b u t e s c o n s i d e r e d i n r e s p e c t t o t h e r e l a t i v e v a l u e p l a c e d o n t h e a t t r i b u t e i n t h e m o d e c h o i c e d e c i s i o n . T h a t i s ; d i s u t i l i t y f o r a n y a t t r i b u t e i s t h e p r o d u c t o f a w e i g h t i n g c o e f f i c i e n t a n d t h e n u m b e r o f u n i t s o f t h e a t t r i b u t e e x p e r i -e n c e d , o r •U? , = V . X ? , w h e r e : 1 , k l l , k V . = v a l u e u s e r k p l a c e s o n a t t r i b u t e i X ? k = m e a s u r e o f a t t r i b u t e i o f m o d e j a s p e r c e i v e d ' b y u s e r k . C o n s e q u e n t l y , m o d e 1 i s a c c e p t e d a n d m o d e 2 i s r e j e c t e d w h e n P 1 P 2 Z V . X 7 . < Z V . X 7 . o r . , i i , k . , I l , k i = l ' i = l P i 2 Z V . ( X T . - X , ) < 0 i = 1 l i , k i , k ' S e v e r a l a s p e c t s o f t h i s d i s u t i l i t y f u n c t i o n a r e n o t e -w o r t h y . F i r s t , t h e f u n c t i o n i s d e s c r i b e d i n t e r m s o f r e l a t i v e d i s u t i l i t i e s o f t w o a l t e r n a t i v e s ( i . e . , a b i n a r y c h o i c e p r o b l e m ) . T h e f u n c t i o n h a s b e e n d e r i v e d h e r e u s i n g d i f f e r e n c e s b e t w e e n a t t r i b u t e s o f t h e t w o m o d e s , b u t t h e f o r m o f t h e i n e q u a l i t y r e m a i n s t h e s a m e i f r a t i o s a r e u s e d ( i . e . , t h e r i g h t h a n d s i d e 171. would be < 1 f o r r a t i o s , r a t h e r than < 0). Secondly, the f u n c t i o n a p p l i e s o n l y t o a s i n g l e i n d i v i d u a l . I n d i v i d u a l 2 u t i l i t i e s are not comparable. That i s , the f u n c t i o n des-c r i b e s the r e l a t i v e d i s u t i l i t i e s of each a t t r i b u t e f o r the mode c h o i c e d e c i s i o n , but the s t r e n g t h of acceptance of a mode by one i n d i v i d u a l cannot be compared w i t h the s t r e n g t h o f another i n d i v i d u a l ' s acceptance and t h e r e f o r e i n d i v i d u a l t o t a l d i s u t i l i t i e s are not a d d i t i v e . * However, i f the v e c t o r s X are t r e a t e d as random v e c t o r s a p r o b a b i l i t y d i s t r i b u t i o n can be determined which w i l l be a s t a t i s t i c a l d e s c r i p t i o n o f the ag g r e g a t i o n of i n d i v i d u a l k, where k=l,N. A t h i r d a s p e c t o f the d i s u t i l i t y f u n c t i o n i s t h a t the i n e q u a l i t y suggests the co n n e c t i o n between i n d i v i d u a l d i s u t i l i t y f u n c t i o n s and d i s c r i -minant f u n c t i o n s . The r e l a t i v e d i s u t i l i t y f u n c t i o n p o s t u l a t e s an i n e q u a l i t y , or a boundary, on one s i d e o f which one mode i s chosen and on the ot h e r s i d e o f which the ot h e r mode i s chosen. Comparing i n d i v i d u a l s i n terms of which s i d e of the boundary c o n d i t i o n they f a l l i s the problem of m u l t i p l e d i s c r i m i n a n t a n a l y s i s , and the d i s c r i m i n a n t a n a l y s i s g i v e s a boundary c o n d i -t i o n which s e p a r a t e s the modal groups on the b a s i s o f t h e i r average d i s u t i l i t y , as measured by the parameter v a l u e s and v a r i a b l e s of the d i s c r i m i n a n t f u n c t i o n . The d i s u t i l i t y v a l u e -Furthermore i f more than two modes were c o n s i d e r e d (the mode c h o i c e d e c i s i o n has alv/ays, t o date, been handled as a b i n a r y c h o i c e problem) we cannot say t h a t aggregated i n d i v i d u a l u t i l i t i e s are t r a n s i t i v e , i . e . r a t i o n a l . That i s , i f a m a j o r i t y of people p r e f e r mode 1 to mode 2 and mode 2 to mode 3 we cannot say t h a t a m a j o r i t y p r e f e r s mode 1 to mode 3: (see Ref. 2, pp.2-3). 1 7 2 . w e i g h t i n g V f o r t h e i n d i v i d u a l i s a n a l o g o u s t o t h e v e c t o r o f p a r a m e t e r s v o f t h e d i s c r i m i n a n t f u n c t i o n . L a s t l y , n o t e a l s o t h a t d i s u t i l i t y i s d e s c r i b e d i n t e r m s o f p e r c e i v e d d i f f e r e n c e s b e t w e e n m o d a l a t t r i b u t e s . U t i l i t y ( d i s u t i l i t y ) i s p u r e l y s u b -j e c t i v e a n d d e p e n d s o n s u b j e c t i v e v a l u e s f o r t h e v a r i a b l e s o f t h e d i s u t i l i t y f u n c t i o n . O n e d i s a d v a n t a g e o f t h i s a p p r o a c h i s p o s s i b l e i n t e r d e p e n d e n c e b e t w e e n t h e s u b j e c t i v e m e a s u r e g i v e n t h r o u g h i n t e r v i e w o f t h e s y s t e m a t t r i b u t e s a n d t h e p s y c h o l o -g i c a l v a l u e a t t a c h e d t o t h a t a t t r i b u t e . T h a t i s , i f a n i n d i -v i d u a l p l a c e s g r e a t v a l u e o n t r a v e l t i m e , h e m a y e s t i m a t e h i s a c t u a l t r a v e l t i m e t o w o r k m u c h g r e a t e r t h a n i t a c t u a l l y i s ( i . e . , b y o b j e c t i v e m e a s u r e m e n t s ) o r t h a n h e w o u l d e s t i m a t e i t t o b e i f h i s v a l u e o f t r a v e l t i m e w a s l e s s . T h e r e m a y a l s o b e s o m e i n t e r c o r r e l a t i o n b e t w e e n t h e e x i s t i n g l e v e l o f s e r v i c e a n d s u b j e c t i v e e v a l u a t i o n o f i d e a l l e v e l s o f s e r v i c e p r e f e r r e d . T h e s e p r o b l e m s a r e d i s c u s s e d l a t e r . T h e s h i f t p r o p e n s i t y s c h e m a m a y b e o u t l i n e d i n t e r m s o f i n d i f f e r e n c e c u r v e a n a l y s i s u s i n g s t a t e d p r e f e r e n c e s a s f o l l o w s . C o n s i d e r 1 ^ , 1 ^ , t h e i n d i f f e r e n c e c u r v e f o r i n d i v i d u a l k , w h i c h i s t h e l o c u s o f a l l c o m b i n a t i o n s o f t w o s y s t e m a t t r i -b u t e s ( s a y o v e r a l l t r a v e l t i m e a n d o v e r a l l t r a v e l c o s t ) w h i c h d e s c r i b e s h i s p r e f e r e n c e s w i t h i n t h e c o n t e x t o f h i s b u d g e t c o n s t r a i n t s a n d t h e m o d e s a v a i l a b l e t o h i m ( F i g u r e 7 ) . U ^ i s t h e p o i n t a t w h i c h t h e t i m e - c o s t c o m b i n a t i o n g i v e s h i m l e a s t 1 7 3 . OVERALL TRAVEL TIME OVERALL TRAVEL COST FIGURE 7 INDIFFERENCE CURVE ILLUSTRATING DISUTILITY OF COMBINATIONS OF TIME AND COST OF TWO MODES FOR A HYPOTHETICAL INDIVIDUAL k 174. d i s s a t i s f a c t i o n , and t h e r e f o r e r e p r e s e n t s the d i s u t i l i t y o f the c h a r a c t e r i s t i c s of mode used, i f we assume the modal 2 a t t r i b u t e s are con t i n u o u s . On the other hand, U^ . r e p r e s e n t s the c h a r a c t e r i s t i c s of the mode r e j e c t e d and i s always t o the r i g h t of 1^1^ s i n c e the d i s u t i l i t y of t h i s combination i s g r e a t e r than t h a t of the mode used. However, the c h a r a c t e r i s -2 t i c s of Uj, can be changed i n such a way t h a t i n d i v i d u a l k w i l l be i n d i f f e r e n t to whether he continues to use the e x i s t i n g mode or s h i f t s t o the a l t e r n a t i v e . T h i s p o i n t i s shown a t 3 which i n t h i s i l l u s t r a t i o n r e s u l t s from d e c r e a s i n g the c o s t of the a l t e r n a t i v e . The r e l a t i v e a t t r i b u t e v a l u e s (X) of to de f i n e , a r e l a t i v e d i s u t i l i t y f u n c t i o n f o r the i n d i v i d u a l , and des-c r i b e s h i s p r o p e n s i t y to s h i f t mode. These r e l a t i v e v a l u e s can then be p l o t t e d i n ( t h i s case) two d i m e n s i o n a l space r e p r e -s e n t i n g the l o c a t i o n of t h a t i n d i v i d u a l v i s - a - v i s a l l o t h e r i n d i v i d u a l s . Assume t h a t r e p r e s e n t s ( f o r these two a t t r i -butes) the c l u s t e r of p r o p e n s i t y ( d i s u t i l i t y ) measures f o r those i n d i v i d u a l s of one socioeconomic group (say low income) w h i l e U k 2 r e p r e s e n t s the c l u s t e r o f p r o p e n s i t y measures f o r another m u t u a l l y e x c l u s i v e group (say h i g h income) ( F i g u r e 8). I f t h e r e i s s u f f i c i e n t d i f f e r e n t i a t i o n between the c l u s t e r s r e p r e s e n t i n g the w i t h i n group v a r i a t i o n we may say t h a t f o r these a t t r i b u t e s t h e r e e x i s t s a d i f f e r e n t combination of a t t r i -butes a t which low income groups would s h i f t t o t r a n s i t than t h a t combination a t which high income groups would s h i f t . The 1 7 5 . (x 3 2 - x 2 ) RELATIVE TRAVEL TIME RELATIVE TRAVEL COST FIGURE 8 CLUSTERS OF OBSERVATIONS ON RELATIVE DISUTILITY VALUES FOR INDIVIDUALS OF TWO HYPOTHETICAL SOCIOECONOMIC GROUPS 176. d i s t a n c e between the means of the c l u s t e r s and the o v e r l a p of val u e s g i v e s a s t a t i s t i c a l measure of the degree t h i s d i f f e r e n -t i a t i o n e x i s t s , and i s found by the use o f d i s c r i m i n a n t a n a l y s i s . A d i s c r i m i n a n t f u n c t i o n can be found f o r each group or sub-group which q u a n t i t a t i v e l y d e s c r i b e s any group o r sub-group's tendency to s h i f t mode. When a group d i s c r i m i n a n t f u n c t i o n i s v a l u e d i t can be used t o p r e d i c t the p r o p e n s i t y to s h i f t mode. That i s , the z v a l u e of any i n d i v i d u a l can be found and h i s group i d e n t i f i e d . S i n c e the z v a l u e i s a f u n c t i o n of systems a t t r i b u t e s and i n d i -v i d u a l v a l u e o r i e n t a t i o n s (which here are assumed s t a b l e i . e . , as parameters) any change i n the system a t t r i b u t e s w i l l change the z v a l u e . I f any i n d i v i d u a l ' s z v a l u e changes enough i t w i l l t r a n s f e r him from the r e g i o n o f mode 1 to the r e g i o n of mode 2. A t some extreme change i n system a t t r i b u t e s a l l z va l u e s change s u f f i c i e n t l y t h a t a l l members of the r e g i o n of mode 1 are t r a n s f e r r e d t o the r e g i o n of mode 2. For any g i v e n p o l i c y change, the p r o b a b i l i t y of an i n d i v i d u a l remaining a ca r d r i v e r , o r s h i f t i n g to a new mode can be determined. Con-v e r s e l y , the p r o b a b i l i t y of an i n d i v i d u a l s h i f t i n g mode can be s t a t e d as: P(X) = l + e Z i n which z i s the d i s c r i m i n a n t f u n c t i o n v a l u e (or d i s c r i m i n a n t score) f o r each i n d i v i d u a l as a c a r d r i v e r and i n h i s p o t e n t i a l group as a new mode u s e r . The d i s c r i m i n a n t r u l e w i l l a s s i g n 177. him to the new mode i f h i s z v a l u e i s " c l o s e r " to the mean of the new mode group than to the mean of the c a r group; o t h e r -wise the r u l e w i l l l e a v e him a member of the c a r group. The method presumes some r e s t r i c t i v e p r e c o n d i t i o n s . Assumption are (1) t h a t every i n d i v i d u a l i s aware of the poten-t i a l a l t e r n a t i v e s , (2) t h a t h i s p r e f e r e n c e s are r a t i o n a l i n terms of the u t i l i t y p o s t u l a t e of maximizing s a t i s f a c t i o n s (3) t h a t h i s beh a v i o r and s t a t e d p r e f e r e n c e s are c o i n c i d e n t and (4), r e l a t e d to (3), t h a t h i s p e r c e p t i o n of a p r e f e r r e d system i s independent of the e x i s t i n g l e v e l o f s e r v i c e . Assumption (1) and (2) p r e s e n t no p a r t i c u l a r problem s i n c e these are i n t r i n s i c assumptions of any a n a l y s i s u s i n g u t i l i t y t h e o r y . Assumption (3) i s important to p r a c t i c a l a p p l i -c a t i o n o f the model as a d e v i c e f o r making t r a n s p o r t a t i o n d e c i -s i o n s , and t h e r e f o r e deserves some d i s c u s s i o n . The congruence of s t a t e d p r e f e r e n c e s and b e h a v i o r i s t i e d t o the r e l a t i o n s h i p between an i n d i v i d u a l ' s v a l u e system as m a n i f e s t e d i n s p e c i f i c a t t i t u d e s and b e h a v i o r a l response. E a r l y b e h a v i o r a l i s t s who b e l i e v e d i n the m e c h a n i s t i c b e h a v i o r i s t system of s t i m u l u s -response and r e s u l t i n g h a b i t p a t t e r n s f e l t t h a t a t t i t u d e s were redundant i n e x p l a i n i n g s o c i a l phenomena. L a t e r , however, i t was r e c o g n i z e d by s o c i a l b e h a v i o r i s t s (e.g., F.H. A l l p o r t ) t h a t the concept of a t t i t u d e was needed to g i v e r e a l i t y to the i d e a o f the m e c h a n i s t i c model of man. Th i s concept was f i r s t i n t r o d u c e d i n t o the b e h a v i o r i s t i c system as a p r e d i s p o s i t i o n to 1 7 8 . respond, and l a t e r i n terms of the s u b j e c t i v e meaning the a t t i t u d e had f o r the i n d i v i d u a l . ^ Modern d e f i n i t i o n s of the a t t i t u d e concept as i t a f f e c t s b e h a v i o r range from a "tendency 4 or d i s p o s i t i o n to e v a l u a t e an o b j e c t " by Katz and S t o l l a r d w i t h an i m p l i c i t b e h a v i o r a l component, to "tendencies to r e a c t " 5 by Lambert and Lambert with i t s e x p l i c i t b e h a v i o r a l component. The c u r r e n t concensus i s t h a t a t t i t u d e s and b e h a v i o r are i n t e r -r e l a t e d although the r e l a t i o n s h i p may go from a very weak con-n e c t i o n t o a very s t r o n g one. In the p r e s e n t case i t i s pos-t u l a t e d t h a t i n d i v i d u a l s can a r t i c u l a t e t h e i r e v a l u a t i o n of the t r a n s p o r t a t i o n systems a t t r i b u t e s i n terms of p r e f e r e n c e s , and t h a t i f these a t t r i b u t e s are i n c l u d e d i n a new arrangement there w i l l be a tendency to r e a c t a c c o r d i n g l y . Assumption (4) presupposes t h a t i n d i v i d u a l t r a v e l l e r s can p e r c e i v e a t r a n s p o r t a t i o n system independently of the e x i s t i n g l e v e l of s e r v i c e . No s y s t e m a t i c study i s a v a i l a b l e on t h i s p o i n t , but the v a l i d i t y of t h i s assumption i s examined l a t e r . The s h i f t p r o p e n s i t y model i s meant to serve as the b a s i s f o r a c o n t r o l mechanism i n the c o n t e x t of forward s e e k i n g , g o a l o r i e n t e d , i n c r e m e n t a l p l a n n i n g . By s i m u l a t i n g p o l i c y i n the model, the number of c a r d r i v e r s who s h i f t can be e s t i m a t e d . Because p o l i c y o p t i o n s are i n c r e m e n t a l i n c h a r a c t e r , the a c t u a l r e s u l t s of such changes can be observed i n the f i e l d . I f the f i e l d r e s u l t s do not conform to e x p e c t a t i o n s as d e r i v e d from the model, the model can be changed a c c o r d i n g l y . 179 . SHIFT PROPENSITY OF NORTH SHORE COMMUTERS The p l a n n i n g model as o u t l i n e d above was e m p i r i c a l l y t e s t e d u s i n g a sample of the c a r d r i v i n g p o p u l a t i o n o f the commuters from the North Shore communities t o the CBD of Vancouver to study the impact of (1) a s i m u l a t e d park and r i d e system, and (2) changes i n the use of t r a n s i t i f p a r k i n g c o s t s were i n c r e a s e d . The performance dimensions are those which d e f i n e the r e l a t i v e v a l u e s of a p r e f e r r e d l e v e l of s e r v i c e to a c t u a l l e v e l of s e r v i c e by c a r . The e x p l a n a t o r y v a r i a b l e s were those which d e f i n e d the p r e f e r r e d l e v e l of s e r v i c e i f a s h i f t was to occur and those which d e f i n e d the a c t u a l l e v e l of s e r v i c e e x p e r i e n c e d a t the time o f the t r i p . Car d r i v e r s were asked t o i n d i c a t e on a c a t e g o r i z e d s c a l e the minimum q u a l i t y o f s e r v i c e d e s i r e d i f he were to use a park and r i d e system, and the maximum charge he would a c c e p t f o r p a r k i n g b e f o r e he would use t r a n s i t . (See q u e s t i o n n a i r e , Appendix B ) . The p r e f e r r e d measure i s the e x p l a n a t o r y v a r i a b l e f o r the i n d i v i d u a l as a h y p o t h e t i c a l t r a n s i t r i d e r and the a c t u a l measure i s the e x p l a -natory v a r i a b l e f o r the i n d i v i d u a l as a c a r d r i v e r . The per-formance dimensions of the t e s t space are t h e r e f o r e the r e l a -t i v e v a l u e o f these v a r i a b l e s . A d e s c r i p t i o n of the dimensions used f o l l o w s . 1 8 0 . R e l a t i v e O v e r a l l T r a v e l Time: (ROTT) The door-to-door journey time by park and r i d e i n 5 minute increments compared to t h a t by car was i n d i c a t e d by the respondent. T h i s v a l u e was then converted to a b s o l u t e t r a v e l time p r e f e r r e d , and t h i s v a l u e compared to the a c t u a l t r a v e l time by c a r . T h i s p r o c e s s was c a r r i e d out so t h a t both d i f f e r e n c e s and r a t i o s c o u l d be used as r e l a t i v e d i s u t i l i t y measures. R e l a t i v e Out-of-Pocket Expenses: (ROPE) The maximum two way combined bus f a r e and p a r k i n g charge t h a t the respondent would i n s i s t upon b e f o r e s h i f t i n g , compared to the a c t u a l p a r k i n g charge l e v i e d . R e l a t i v e R e s i d e n t i a l T r a v e l Time: (RTTO) The walking d u r a t i o n from the p a r k i n g l o c a t i o n to the t r a n s i t v e h i c l e p r e f e r r e d i n a park and r i d e system, compared to the a c t u a l w a l k i n g d i s t a n c e from r e s i d e n c e to c a r a t the t r i p o r i g i n . R e l a t i v e Frequency of S e r v i c e : (RFREQ) The frequency of t r a n s i t v e h i c l e s l e a v i n g the park and r i d e t e r m i n a l i n minutes compared w i t h the a c t u a l frequency of bus s e r v i c e i n the zone of o r i g i n of the c a r d r i v e r . 1 8 1 . R e l a t i v e P a r k i n g Charge: (RPKCHG) The p a r k i n g r a t e a t which the respondent s a i d he would s w i t c h to t r a n s i t i f the p a r k i n g r a t e s were s u b s t a n t i a l l y i n c r e a s e d i n downtown Vancouver, compared to a c t u a l p a r k i n g charge e x p e r i e n c e d a t the time of the journey. I f the p r e f e r r e d s e r v i c e was p r o v i d e d each c a r d r i v e r w i l l i n g to s h i f t mode c o u l d , under the p r e f e r r e d c o n d i t i o n s , be c o n s i d e r e d a user of the multimodal system. The e x i s t i n g c a r d r i v i n g p o p u l a t i o n a c t u a l l y t e s t e d , and the h y p o t h e t i c a l users of the new system then d e f i n e two groups i n two r e g i o n s of the t e s t space. These would i n the s t a t i s t i c a l sense be matched p a i r s w i t h each member of each p a i r ( i . e . , group) being l o c a t e d as two p o i n t s on an i n d i f f e r e n c e s u r f a c e . For 1 3 example, a t p o i n t s and i n F i g u r e 7 f o r the case of two dimensions. The problem i s to f i n d t h a t d i s c r i m i n a n t f u n c t i o n which maximally separates the two groups, and those dimensions which d e f i n e the s e p a r a t i o n . The s i g n i f i c a n t d i s c r i m i n a n t f u n c t i o n v a r i a t e s g i v e a d e f i n i t i o n t o those p o l i c y changes which would encourage c a r d r i v e r s to s h i f t mode. The number of persons which would be c l a s s i f i e d as a multimodal or " t r a n s i t - o n l y " user a t any l e v e l of change i n the system, can be determined. S i n c e some people would s h i f t only under the most extreme c o n d i t i o n s , and because the c r i t i c a l f a c t o r ( s ) to encourage a s h i f t , o r a wide enough upper o r lower l i m i t on 182. the s c a l e may have been m i s s i n g , a f o l l o w up q u e s t i o n was asked to determine i f the respondent would d e f i n i t e l y s w i t c h i f the q u a l i t y of s e r v i c e he s p e c i f i e d as p r e f e r r i n g was a c t u a l l y p r o v i d e d . Those who answered no to t h i s q u e s t i o n were e l i m i n a t e d from the sample, l e a v i n g a t o t a l of 465 respon-dents who s a i d they would i n f a c t s w i t c h i f the s e r v i c e they d e s i r e d was p r o v i d e d . D i s c r i m i n a n t a n a l y s i s was then used to t e s t : (1) i f a c t u a l i n d i v i d u a l b e h a v i o r p r o f i l e s of the o r i g i n a l "anchor" group ( i . e . , a c t u a l c a r d r i v e r s ) were s i g n i -f i c a n t l y d i f f e r e n t from those of the " s h i f t " group ( i . e . , h y p o t h e t i c a l t r a n s i t or multimodal user's p r o f i l e s based on t h a t combination of a t t r i b u t e s which they s a i d would cause them £o^ rshift) ; (2) what dimensions serve to d e f i n e the s e p a r a t i o n between c a r d r i v e r s as c a r d r i v e r s and c a r d r i v e r s as hypothe-t i c a l t r a n s i t u s e r s , and (3) the v a l i d i t y o f the l i n e a r d i s -c r i m i n a n t f u n c t i o n s f o r a p r e d i c t i v e model of mode s h i f t p r o -p e n s i t y . The c e n t r a l t e n dencies of the o b s e r v a t i o n s of the two groups g i v e a g e n e r a l i n d i c a t i o n of the p r e f e r e n c e p a t t e r n of the c a r d r i v i n g p o p u l a t i o n to d i v e r t (Table XXVIIIa). I f the d i s t r i b u t i o n of both groups i s normal, the r e s u l t s of the t a b l e d e s c r i b e those measures needed to b r i n g about a s h i f t of one-h a l f the c a r group. The o t h e r h a l f would be those who r e q u i r e d changes which l o c a t e them below the mean. T h i s s h i f t would occur w i t h a decrease i n mean t r a v e l time of about 5 minutes. T o t a l out of pocket expenses would have to decrease, but not 1 8 3 . Table XXVIIla MEANS AND STANDARD DEVIATIONS FOR CAR GROUP AND SHIFT GROUP, FOR A PROPOSED MARK AND RIDE, AND AN INCREASE IN PARKING CHARGES VARIABLE CAR DRIVERS SHIFT GROUP GROUP MEANS AVERAGE X1(ROTT) 3 0 . 8 4 9 2 5 . 8 0 6 2 8 . 3 2 8 X 2(ROPE) . 5 4 9 . 5 3 3 . 5 4 1 X 3(RTTO) . 6 6 9 2 . 0 2 2 1 . 3 4 5 X 4(RFREQ) 1 7 . 4 0 9 4 . 5 0 3 1 0 . 9 5 6 X c(RPKCHG) . 5 4 9 1 . 0 1 1 . 7 8 0 GROUP STANDARD DEVIATION AVERAGE X x(ROTT) 8 . 3 8 1 8 . 7 9 9 8 . 9 5 1 X 2(ROPE) . 4 2 0 . 3 2 8 . 3 7 7 X 3(RTTO) 1 . 5 5 4 . 9 5 3 1 . 4 5 5 X 4(RFREQ) 4 . 8 7 0 2 . 1 9 2 7 . 4 7 8 X c(RPKCHG) . 4 2 0 . 5 3 2 . 5 3 2 s u b s t a n i a l l y The o v e r a l l w a l k i n g time from the p a r k i n g l o t of a park and r i d e s t a t i o n to the bus compared w i t h the e x i s t i n g time a t the r e s i d e n t i a l end of the journey ( f o r a l l p r a c t i c a l purposes t h i s i s n i l l ) would have t o be about 2 minutes. T h i s i n f e r s t h a t d r i v e r s would t o l e r a t e some wa l k i n g at the r e s i d e n -t i a l end of the t r i p (as they i n g e n e r a l do a t the CBD end) 1 8 4 . i f o t h e r d e s i r a b l e c h a r a c t e r i s t i c s a r e p r o v i d e d . O n e c h a r a c -t e r i s t i c w h i c h s h o w s u p v e r y d r a m a t i c a l l y i s a l a r g e r e d u c t i o n i n t h e f r e q u e n c y o f p u b l i c t r a n s i t v e h i c l e s w i t h i n t h e m u l t i -m o d a l s y s t e m c o m p a r e d w i t h t h e f r e q u e n c y o f t h e b u s e s t h e r e s -p o n d e n t p e r c e i v e s a t h i s h o m e l o c a t i o n . T h e a v e r a g e c a r d r i v e r , w h o i s a p o t e n t i a l " s h i f t " p a t r o n w o u l d r e q u i r e a b o u t 4 . 5 m i n u t e h e a d w a y b e t w e e n b u s e s c o m p a r e d w i t h t h e m o r e t h a n 17 m i n u t e s h e p e r c e i v e s a t p r e s e n t . S o m e c a u t i o n i s n e c e s s a r y i n t h e i n t e r p r e t a t i o n o f t h e s e d a t a . F i r s t , l a r g e s t a n d a r d d e v i a t i o n s f o r t h e o u t - o f -p o c k e t c o s t f a c t o r r e s u l t s f r o m a f e w e x t r e m e o b s e r v a t i o n s ; t h o s e w h o p a y a v e r y h i g h p a r k i n g c o s t a t p r e s e n t , a n d t h o s e w h o d e m a n d a v e r y l o w t o t a l e x p e n s e f o r t h e s h i f t c o n d i t i o n . M a n y r e s p o n d e n t s i n d i c a t e d t h e y d e s i r e d a s y s t e m w i t h n o o u t -o f - p o c k e t e x p e n s e s . S e c o n d l y , t h e s p r e a d b e t w e e n e x i s t i n g f r e q u e n c y a n d t h a t p r e f e r r e d m a y b e d r a m a t i z e d b y t h e w a y t h e s e w e r e m e a s u r e d . R e c a l l t h a t t h e e x i s t i n g f r e q u e n c y i s a r u s h p e r i o d a v e r a g e f o r t h e z o n e o f o r i g i n f o r e a c h d r i v e r a n d m a y n o t r e p r e s e n t t h e c o m b i n a t i o n o f e x t r e m e l y h i g h o r e x t r e m e l y l o w e x i s t i n g f r e q u e n c i e s w i t h e x t r e m e l y l o w o r e x t r e m e l y h i g h p r e f e r r e d f r e q u e n c i e s o n t h e i n d i v i d u a l b a s i s . I f p r e c i s e f r e q u e n c i e s w e r e u s e d f o r t h e h o u r o f d e p a r t u r e t h e s p r e a d i n m e a n s w o u l d d e c r e a s e , a n d t h e e f f e c t o f t h i s f a c t o r w o u l d b e e x p e c t e d t o m o d e r a t e s o m e w h a t . . 1 8 5 . The p a r k i n g charge needed, by i t s e l f , to e f f e c t the s h i f t would be from about an average of $.55 to about $1.00 per day. S t a t i s t i c a l t e s t s (Table XXIX) show an o v e r a l l d i s -c r i m i n a t i o n between the two groups f o r both a park and r i d e 2 system of R = .762, and i n terms of the r a i s i n g of p a r k i n g 2 2 f e e s an R = .175. Both R v a l u e s are s i g n i f i c a n t . The 2 r e l a t i v e l y l a r g e R v a l u e f o r d i s c r i m i n a t i o n between what e x i s t s now and a new combination of c h a r a c t e r i s t i c s i n a park and r i d e system shows a r e a l i z a b l e multimodal system to be p e r c e i v e d . However, s u b s t a n t i a l changes i n s e r v i c e l e v e l s are p e r c e i v e d n e c e s s a r y . The u n i v a r i a t e F - t e s t shows the s c a l e of changes needed f o r a s h i f t c o n s i d e r i n g each a t t r i b u t e by i t s e l f . For the park and r i d e system, the frequency of buses a t the t e r m i n a l , the d i s t a n c e t o walk to the t e r m i n a l from p a r k i n g l o c a t i o n are c r i t i c a l f a c t o r s as w e l l as the over-a l l e l a p s e d t r a v e l time. The change i n p a r k i n g charges a l s o i s e f f e c t i v e i n d i s c r i m i n a t i n g between the groups a t the p < .001 s i g n i f i c a n c e l e v e l , i n d i c a t i n g t h a t an i n c r e a s e i n p a r k i n g charges w i l l cause c a r d r i v e r s to s h i f t t o the bus. In the reduced space the group means show s i g n i f i c a n t s e p a r a t i o n f o r both the multimodal system and p a r k i n g fee charges. The v e c t o r l o a d i n g s on the d i s c r i m i n a t o r show t h a t bus frequency dominates the p r e f e r e n c e p a t t e r n of the " s h i f t " group (Table XXX). T h i s r e f l e c t s the d i f f e r e n c e s found between 186. TABLE XXIX S T A T I S T I C A L TESTS ON PROPENSITY OF MODE SHIFT FOR THE CAR GROUP AND SHIFT GROUP FOR A PROPOSED MULTIMODAL SYSTEM AND FOR A TRANSIT SYSTEM BASED ON INCREASED PARKING CHARGES UNIVARIATE F-TESTS VARIABLE F-RATIO F P X 1 ( R O T T ) 80.09 <.001 X 2(ROPE) .47 n . s . X 3 ( R T T O ) 256.03 ,<.001 X 4(RFREQ) 2715.61 <.001 X c(RPKCHG) 215.20 <.001 SIGNIFICANCE OF DISCRIMINATOR AND GROUP SEPARATION MULTIMODE TRANSIT DISCRIMINATOR GROUP DISCRIMINATOR SEPARATION GROUP SEPARATION A = .2369 D 2 = 147.45 A .8118 D 2 = .213 F l = 4.0 F l = 1 F 2 = 925.0 F o = 685.0 D^ F 2 928.0 F o = 49.8 D^ F = H2 744 .90 F .001 P F H2 215.20 F <.001 P F < P .001 F P < .001 R 2 = .762 R 2 = .175 SIGNIFICANCE : OF ROOT N o . o f R o o t % o f R o o t s (X n - ) T r a c e 1 3.2212 100.0 1 3.2212 100.0 1 . 2319 100.0 N o . o f R o o t s S u m o f S u m m e d R o o t s d . f . X 2 X p MULTIMODE 4 3.2212 4 312.5 <.001 TRANSIT  1 .2319 1 430.0 <.001 187 . Table XXX VECTOR LOADINGS ON DISCRIMINATORS VARIABLE SCALED VECTOR X 1(ROTT) X 2(ROPE) X 3(RTTO) X 4(RFREQ) -17.85 108.13 -11.48 .43 X c(RPKCHG) 14.61 the frequency p r e f e r r e d f o r each t r i p a g a i n s t t h a t averaged by zone and averaged over the rush p e r i o d . O v e r a l l t r a v e l time f o l l o w e d by r e s i d e n t i a l t r a v e l time a l s o c o n t r i b u t e sub-s t a n t i a l l y to the s e p a r a t i o n . No s e r i o u s i n t e r c o r r e l a t i o n e x i s t s , although some c o r r e l a t i o n i s e v i d e n t between a c t u a l o v e r a l l t r a v e l time and bus frequency (Table XXXI). T h i s i s to be expected s i n c e bus frequency i n the more remote areas i s low w h i l e auto t r a v e l time i s h i g h , p a r t i c u l a r l y i n the western p o r t i o n of West Vancouver. The d i s c r i m i n a n t f u n c t i o n s o f the anchor group f o r the multimodal system and the t r a n s i t system r e s p e c t i v e l y a r e : z = -10.761 + 0.401X o + 1.221X. am 2 4 z at. = - 0.657 + 2.390X C 188. Table XXXI CORRELATION MATRICES FOR CAR GROUP AND SHIFT GROUP ON MULTIMODAL VARIABLES ROTT ROPE RTTO RFREQ CAR ROTT 1.00 .12 .11 .15 ROTT SHIFT GROUP ROPE- .09 1.00 .12 .15 ROPE GROUP RTTO -.01 .05 1.00 .17 RTTO RFREQ .32 -.05 -.05 1.00 RFREQ Those f o r the " s h i f t " group are r e s p e c t i v e l y : z = -1.940 + 1.216X„ + 0.316X. sm 2 4 z ^ = -2.222 + 4.397X,. s t 5 In the stepwise procedure u s i n g an a c c e p t a n c e - r e j e c t i o n c r i t e r i o n o f F < .05 o v e r a l l t r a v e l time drops o ut of c o n s i d e r a t i o n and P " . the d i s c r i m i n a n t scores are c a l c u l a t e d on the b a s i s of r e s i d e n -t i a l t r a v e l time and frequency. T h i s i n c r e a s e s the F - r a t i o from F = 744.90 t o F = 1484.74 f o r the park and r i d e scheme. The 2 c a n o n i c a l c o r r e l a t i o n , R c = .87, r e s u l t i n g i n an R of .76 i n d i c a t e good d i s c r i m i n a t i o n on these two v a r i a b l e s (Table XXXII). The p o s t e r i o r c l a s s i f i c a t i o n by the d i s c r i m i n a n t f u n c -t i o n s r e s u l t s i n l e s s than one p e r c e n t m i s c l a s s i f i c a t i o n (Table X X X I I I ) . Using only p a r k i n g charge as a v a r i a b l e i n the model produces only moderately s u c c e s s f u l r e s u l t s . T h i s may be 189 Table XXXII SIGNIFICANCE OF DISCRIMINATOR USING ONLY THOSE VARIABLES REMAINING SIGNIFICANT IN THE STEPWISE PROCEDURE MULTIMODE ' TRANSIT F„„ = 1484.74 F„_ = 215.20 R = .873 R = .434 c c R 2 = .760 R 2 = .189 Table XXXIII PREDICTED CLASSIFICATION VERSUS ACTUAL GROUP MEMBERSHIP FOR THE TEST ON THE MULTIMODAL SYSTEM AND TRANSIT SYSTEM ACTUAL NUMBER IN GROUP ACTUAL NUMBER IN GROUP CAR SHIFT CAR SHIFT MULTIMODAL NUMBER PREDICTED TO BE IN GROUP CAR GROUP 457 0 SHIFT GROUP 8 465 MISCLASSIFICATION = TRANSIT NUMBER PREDICTED TO BE IN GROUP CAR GROUP 409 249 SHIFT GROUP 56 216 TOTAL 465 4^5 930 0.9% TOTAL 465 465 930 MISSES _0 8 MISSES 56 249 305 % MISCLASSIFICATION = 3 2.8% 1 9 0 . p a r t i a l l y due to a r e l a t i v e l y crude breakdown i n the p a r k i n g charge c a t e g o r i e s . To determine how many car d r i v e r s would s h i f t to t r a n s i t f o r any g i v e n p o l i c y change, i t i s only necessary to change the v a r i a b l e v a l u e f o r each i n d i v i d u a l and note the new z v a l u e s . T h i s then i s e v a l u a t e d by the model and a new p r o b a b i l i t y found f o r each f u n c t i o n . He i s then a s s i g n e d to t h a t group f o r which he has the l a r g e s t P(X) v a l u e . I t i s e v i d e n t from the v e c t o r l o a d i n g s t h a t a g i v e n percentage change i n frequency w i l l have more e f f e c t on t r a n s f e r r i n g auto d r i v e r s to a park and r i d e system than w i l l the same percentage change i n r e s i d e n t i a l t r a v e l time. V a l i d i t y of P r e f e r e n c e P a t t e r n s The mode s h i f t d e s c r i b e d here i s based on an a n a l y s i s of what people say they would do under a g i v e n h y p o t h e t i c a l s i t u a t i o n . To improve v a l i d i t y only those respondents who s t a t e d a second time t h a t they would s h i f t i f there p r e f e r e n c e s were met were a n a l y s e d . A q u e s t i o n s t i l l remains as to whether the respondents would i n f a c t s h i f t i f t h e i r d e s i r e s were met.. Some attempt was made to f u r t h e r understand the p r e f e r e n c e s t r u c t u r e and to es t i m a t e the v a l i d i t y of s t a t e d p r e f e r e n c e as a t o o l to analyse mode s h i f t . I t was reasoned t h a t i f an i n d i v i d u a l ' s p r e f e r e n c e s were independent of the l e v e l o f e x i s t i n g s e r v i c e i t was l i k e l y 191. t h a t the p r o p e n s i t y was good t h a t a s h i f t would i n f a c t o c c u r . Consequently, a t e s t of the independence of p r e f e r e n c e s from the e x i s t i n g system a t t r i b u t e s was c a r r i e d out u s i n g c a n o n i c a l a n a l y s i s . Table XXXIV shows the c o r r e l a t i o n c o e f f i c i e n t s f o r the 4 v a r i a b l e s r e p r e s e n t i n g e x i s t i n g a t t r i b u t e s and the 5 v a r i a b l e s r e p r e s e n t i n g p r e f e r r e d a t t r i b u t e s . * Simple i n t e r -c o r r e l a t i o n e x i s t s between p r e f e r r e d t r a v e l time (X,.) and a c t u a l t r a v e l time (X^). Using the r u l e of thumb t h a t an r = .65 i s not s e r i o u s i n t e r c o r r e l a t i o n i t i s observed t h a t a l l o t h e r v a r i a t e s are independent between the s e t s . However, the c a n o n i c a l c o r r e l a t i o n between the s e t s i s s i g n i f i c a n t . Two r o o t s w i t h R = .68 and R = .60 are both r c c s i g n i f i c a n t a t p < .001. The i n f e r e n c e i s t h a t the two s e t s of v a r i a t e s can be combined i n such a way to produce c o r r e l a -t i o n between what an i n d i v i d u a l p r e f e r s i n the way of t r a n s -p o r t a t i o n s e r v i c e and the e x i s t i n g a l t e r n a t i v e s a v a i l a b l e . The c o e f f i c i e n t s of the two se t s f o r the 1 s t c a n o n i c a l v a r i a t e s are: x l (0.881) X 5 (0.952) x 2 (0.280) X 6 (0.025) x 3 (-0.135) X 7 (-0.138) X4 (0.121) X 8 X 9 (-0.089 (0.229) • P r e f e r r e d p a r k i n g charges (Xg) i s compared w i t h a c t u a l p a r k i n g charge (X 2) to account f o r the e x t r a v a r i a t e i n the second s e t . 192. Table XXXIV CANONICAL TESTS OF INDEPENDENCE OF PREFERRED ATTRIBUTES WITH ACTUAL ONES CORRELATION MATRIX X l X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 x l 1.00 X 2 -.09 1.00 I 3 -.01 .05 1.00 1 X 4 .32 -.05 -.05 1.00 X 5 .65 .10 -.08 .27 1.00 X 6 .04 .19 -.06 .04 .12 1.00 X 7 -.02 -.02 .10 -.07 .11 .12 1.00 X 8 .03 .03 .07 -.00 .15 .15 .17 1.00 X 9 .09 .60 .02 .01 .13 .17 -.08 -.00 1.00 SIGNIFICANCE OF CANONICAL ROOTS R o o t C a n o n . „ 2 C o r r . X . A ' X d . f . X n (R c ) P 1 .678 .4597 .3405 493.5 20 .001 2 .595 .3528 .6400 202.0 12 .001 3 .155 .0240 .9750 11.7 6 .05 These i n d i c a t e the f a c t o r c o n t r i b u t i n g most to the i n t e r c o r r e -l a t i o n i s the r e l a t i o n s h i p between a c t u a l t r a v e l time and t h a t which i s p r e f e r r e d . The second c a n o n i c a l v a r i a t e s have the f o l l o w i n g c o e f f i c i e n t s : X , ( - 0 . 3 5 5 ) X c ( - 0 . 3 8 1 ) 1 D X „ ( 0 . 9 6 7 ) Xc ( 0 . 1 4 0 ) 2. 6 X 3 ( 0 . 0 3 8 ) X ? ( 0 . 0 8 7 ) X 4 ( 0 . 0 0 8 ) X g ( 0 . 0 5 2 ) X g ( 0 . 9 5 1 ) T h i s v a r i a t e b r i n g s out the remaining i n t e r c o r r e l a t i o n s : t h a t between a c t u a l p a r k i n g c o s t and t h a t p r e f e r r e d . The r e s u l t s i n d i c a t e t h a t as f a r as t r a v e l time and p a r k i n g c o s t f a c t o r s are concerned, c a r d r i v e r s do not e n v i s i o n very r a d i c a l changes to be p o s s i b l e . However, i n d i c a t i o n s are t h a t o t h e r a t t r i b u t e s such as t r a n s i t f a r e s , r e s i d e n t i a l t r a v e l time, and s e r v i c e frequency can be changed i n a way ver y much d i f f e r e n t from t h a t which i s c u r r e n t l y e x p e r i e n c e d . At p r e s e n t no way e x i s t s t o determine the degree t o which s t a t e d p r e f e r e n c e s , or the v a l u e g i v e n to systems a t t r i -b utes, and be h a v i o r are i n t e r r e l a t e d . T h i s a n a l y s i s t h e r e f o r e stops s h o r t of a p r e d i c t i v e model, but does i n d i c a t e very d e f i n i t e l y a p r o p e n s i t y to s h i f t mode based on the f a c t o r s s t u d i e d . I t has been shown t h a t p r a c t i c a l i n c r e a s e s i n p a r k i n g charges i n the CBD by whatever manner, w i l l s i g n i f i c a n t l y a f f e c t mode s p l i t ; and t h a t the r e s i d e n t i a l t r a v e l time, frequency of 1 9 4 . buses l e a v i n g the park and r i d e t e r m i n a l l o c a t i o n and o v e r a l l t r a v e l time can be used as i n s t r u m e n t a l f a c t o r s i n a mode s h i f t p o l i c y . INFLUENCE OF SOCIOECONOMIC CHARACTERISTICS IN MODE SHIFT PROPENSITY The p r o p e n s i t y f o r c a r d r i v e r s to s h i f t mode i s l i k e l y r e l a t e d to the socioeconomic s t r u c t u r e o f the i n d i v i d u a l . S i n c e i t i s re a s o n a b l e t o a s s e r t t h a t each i n d i v i d u a l ' s r e l a t i v e d i s u t i l i t y w i l l depend on such socioeconomic f a c t o r s as age, car ownership, income, and o c c u p a t i o n , each o f these w i l l r e l a t e t o mode s h i f t p r o p e n s i t y through d i f f e r e n t d i s u t i l i t y dimensions. That i s , i t would be expected t h a t age c a t e g o r i e s , f o r example, may i n f l u e n c e the p r o p e n s i t y to s h i f t through a d i f f e r e n t s e t of a t t r i b u t e s than another socioeconomic c h a r a c -t e r i s t i c . I f the dimensions which d i s t i n g u i s h between s o c i o -economic c h a r a c t e r i s t i c s can be found, and i f they are s i g n i -f i c a n t i n c l a s s i f y i n g the v a r i o u s c h a r a c t e r i s t i c s we can then a s s e r t t h a t changes i n the system w i l l d i f f e r e n t i a l l y a f f e c t the v a r i o u s groups t h a t have a p r o p e n s i t y to s h i f t mode. F o r example c o s t changes may have more i n f l u e n c e on s e p a r a t i n g the d i f f e r e n t income c a t e g o r i e s and t h e r e f o r e w i l l encourage, say more low income workers to s h i f t than h i g h income ones. A s e r i e s of t e s t s were performed to determine the r e l a t i v e d i s u t i l i t i e s of the car d r i v i n g group. No agreement e x i s t s i n . t h e l i t e r a t u r e as to the b e s t way to express r e l a t i v e 1 9 5 . d i s u t i l i t y . Some i n v e s t i g a t o r s have used d i f f e r e n c e s between car and t r a n s i t a t t r i b u t e s , some r a t i o s , and some have found t r a n s f o r m a t i o n s of the raw measures more u s e f u l . P r e l i m i n a r y t e s t s u s i n g both d i f f e r e n c e measures and r a t i o measures were conducted to attempt to r e s o l v e t h i s dilemma. The t e s t s showed t h a t r a t i o s produced b e t t e r d i s c r i m i n a t i o n between groups w i t h more o f the v a r i a b l e s p r o v i n g s i g n i f i c a n t . T h i s f i n d i n g p l u s the f a c t t h a t most of the t r a n s p o r t a t i o n study r e s e a r c h has used r a t i o s r e s u l t e d i n the d e c i s i o n to use r a t i o s i n t h i s a n a l y s i s as the measure of r e l a t i v e d i s u t i l i t y . The s h i f t v a r i a b l e s were then expressed as a r a t i o of a c t u a l s t a t e o f the system as p e r c e i v e d by the i n d i v i d u a l d i v i d e d by the p r e -f e r r e d s t a t e of the system b e f o r e a mode s h i f t would o c c u r . That i s : X-^  = a c t u a l o v e r a l l t r a v e l time * p r e f e r r e d o v e r a l l t r a v e l time. X„ = a c t u a l charge p a i d f o r p a r k i n g -f p r e f e r r e d o u t - o f - p o c k e t expenses f o r both t r a n s i t f a r e and p a r k i n g . X~ = a c t u a l walking time from o r i g i n t o v e h i c l e ^ p r e f e r r e d w a l k i n g time a t park and r i d e t e r m i n a l . X. = a c t u a l frequency of bus a t o r i g i n zone + p r e f e r r e d frequency of t r a n s i t v e h i c l e l e a v i n g park and r i d e t e r m i n a l . Xj. = a c t u a l charge p a i d f o r p a r k i n g -f p a r k i n g charge t h a t would cause a mode s h i f t . These r a t i o v a r i a b l e s may be i n t e r p r e t e d i n terms of s a t i s f a c -t i o n w i t h the e x i s t i n g l e v e l of s e r v i c e i n the f o l l o w i n g manner: f o r the park and r i d e s e r v i c e (X, to X.), i f X < 1 the i n d i v i d u a l 196. i s not s a t i s f i e d w i t h h i s s e r v i c e and would need an improved l e v e l of s e r v i c e (decreased d i s u t i l i t y ) i n a new system. For CBD p a r k i n g p o l i c y , X,. i s always l e s s than one because the r a t i o presumes some change upward i n p a r k i n g fees i s necessary to cause a s h i f t . A m a t r i x of r e l a t i v e d i s u t i l i t y s c o r e s was developed and a program w r i t t e n to punch the v a r i a b l e s on cards f o r the 465 c a r d r i v e r s who s t a t e d they would s w i t c h to a new mode i f c e r t a i n changes were made (See Appendix H). Age as a F a c t o r i n P r o p e n s i t y to S h i f t Mode Best r e s u l t s were achieved when the age groups were s p l i t i n t o those under 40 and those over 40. For a l l a t t r i b u t e s those over 40 r e q u i r e a r e l a t i v e l y h i g h e r l e v e l of s e r v i c e on the multimodal system b e f o r e s h i f t i n g mode than those under 40, as shown by the lower v a l u e s f o r r e l a t i v e d i s u t i l i t y r a t i o s f o r the over 40 group (Table XXXV). S t a t i s t i c a l t e s t s are shown on Table XXXVI. The u n i v a r i a t e F t e s t s show t h a t t r a v e l time and frequency are the dimensions through which age i s an i n -f l u e n c e i n the mode s h i f t . Group d i s c r i m i n a t i o n on a l l a t t r i -butes and group s e p a r a t i o n i n the reduced space are both s i g n i -f i c a n t . When the v e c t o r i s s c a l e d (Table XXXVII), o u t - o f - p o c k e t expenses a l s o show important i n f l u e n c e s , which i s hidden o t h e r -wise by the l a r g e s t a n d a r d d e v i a t i o n of t h i s v a r i a b l e . The assignment t e s t u s i n g only t r a v e l time and frequency dimensions produced an F. p r o b a b i l i t y of p < .001 and a c a n o n i c a l c o r r e l a t i o n 1 9 7 . Table XXXV AGE GROUP MEANS AND STANDARD DEVIATIONS FOR THOSE UNDER 40 AND THOSE OVER 40 VARIABLE X 1(OTT) X 2(OPE) X 3(TTO) X 4(FREQ) X 5(PKCHG) UNDER 4 0 * OVER 4 0 * * GROUP MEANS 1 . 0 9 0 3 . 2 5 6 . 3 7 9 4 . 8 7 8 . 6 1 3 . 9 5 9 2 . 0 6 8 . 3 7 7 3 . 9 1 0 . 5 6 1 AVERAGE 1 . 0 2 2 2 . 6 3 3 . 3 7 8 4 . 3 7 0 . 5 8 6 X1(OTT) X 2(OPE) X 3(TTO) X 4(FREQ) X 5(PKCHG) •Sample = 2 2 1 **Sample = 2 4 4 GROUP STANDARD DEVIATION AVERAGE . 6 0 4 . 5 3 5 . 5 7 2 1 2 . 2 2 7 9 . 2 8 8 1 0 . 7 9 0 . 8 0 7 . 8 1 8 . 8 1 2 3 . 0 5 7 2 . 7 6 1 2 . 9 4 2 . 7 2 6 . 6 4 1 . 6 8 3 1 9 8 T a b l e XXXVI S T A T I S T I C A L TESTS OF THE PROPENSITY OF AGE GROUPS TO SHIFT MODE UNIVARIATE F TESTS FOR AGE GROUPS VARIABLE F-RATIO . F P X ^ O T T ) 6 . 2 0 < . 0 5 X 2 ( O P E ) 1 . 4 1 n . s . X 3 ( T T O ) . 0 0 n . s . X^(FREQ) 1 2 . 8 7 < . 0 0 1 X 5(PKCHG) . 6 8 n . s . SIGNIFICANCE OF DISCRIMINATOR AND GROUP SEPARATION A — . 9 6 1 3 . 5 8 1 4 F l = 5 . 0 F5 4 5 9 13 . 4 F 2 = 4 5 9 . 0 F H 2 = 3 . 6 9 5 F < P . 0 0 1 F P < . 0 1 R 2 . 0 2 9 SIGNIFICANCE OF ROOTS No. o f R o o t % R o o t No. P o s s i b l e 2 R o o t s X- i s o f R o o t s 2 R o o t s d . f . x x 1 T r a c e P 0 4 0 3 1 0 0 . 0 5 . 0 4 0 3 5 * 3 7 . 3 < . 0 0 1 • I n c l u d e s PKCHG 199. Table XXXVII VECTOR LOADINGS ON DISCRIMINATOR VARIABLE SCALED VECTOR X 1(OTT) 5.98 X 2(OPE) 37.67 X 3(TTO) -.56 X^(FREQ) 47.46 Xc(PKCHG) 2.12 2 of R c = .19, wit h an e q u i v a l e n t R = .03, w i t h no r e d u c t i o n from the t e s t w i t h a l l v a r i a b l e s (Table XXXVIII). Table XXXVIII SIGNIFICANCE OF DISCRIMINATOR USING ONLY SIGNIFICANT VARIABLES F 2 = r 462 8.80 F < P .001 R .19 c R 2 = .028 f u n c t i o n s der minant f u n c t i o n s are f o r under 40 and over 40 r e s p e c t i v e l y : z -rt = -2.987 + 3.135X, + 0.524X., and u40 1 4 z .„ = -2.144 + 2.777X, + 0.415X.. o40 1 4 200. The p o s t e r i o r c l a s s i f i c a t i o n u s i n g these f u n c t i o n s i n the s h i f t model r e s u l t e d i n 40.6 p e r c e n t m i s c l a s s i f i c a t i o n (Table XXXIX). Table XXXIX PREDICTED CLASSIFICATION VERSUS ACTUAL GROUP MEMBERSHIP FOR UNDER 40 AND OVER 40 ACTUAL NUMBER IN GROUP U40 o40 NUMBER PREDICTED TO BE IN GROUP U40 113 81 o40 108 163 % MISCLASSIFIED = 40.6% TOTAL 321 344 465 MISSES 108 81 189 The t e s t s show t h a t age should be c o n s i d e r e d i n the p r e d i c t i o n o f who would s h i f t to a new system, w i t h those i n the younger age groups more l i k e l y to s h i f t than those i n the o l d e r age groups, w i t h i n c r e m e n t a l changes i n system performance. Bus frequency a t the park and r i d e t e r m i n a l i s p a r t i c u l a r l y important f o r those over 40 as i s o v e r a l l t r a v e l time. When the e i g e n v e c t o r i s s c a l e d to account f o r the l a r g e v a r i a n c e i n ou t - o f - p o c k e t expense r a t i o f o r these ages, t h i s v a r i a b l e i n -creases i n i t s r o l e i n e x p l a i n i n g the d i f f e r e n c e between groups, showing t h a t the over 40 age group would r e q u i r e a l a r -ger i n c r e a s e i n t r a n s i t f a r e and p a r k i n g c o s t s than those under 40. 201. I t appears t h a t changes i n the CBD p a r k i n g r a t e s would not have a d i f f e r e n t i a l e f f e c t a c c o r d i n g to age c a t e -gory, w i t h those i n the o l d e r age group as l i k e l y to s h i f t w i t h a g i v e n change as those i n the younger age group. Car Ownership as a F a c t o r i n P r o p e n s i t y to S h i f t Mode Th i s v a r i a b l e was d i c h o t o m i z e d i n t o a s i n g l e c a r ownership ca t e g o r y , and m u l t i p l e c a r ownership one. As one would expect the p r o p e n s i t y to s h i f t mode decreases as c a r ownership i n c r e a s e s (Table XL). For the park and r i d e system the r e l e v a n t dimensions which s e p a r a t e s i n g l e ownership from those f a m i l i e s owning two or more ca r s are o v e r a l l t r a v e l time and r e s i d e n t i a l t r a v e l time w i t h o v er-a l l t r a v e l time the most important dimension i n the s e p a r a t i o n (Table X L I ) . Although the t e s t shows a s i g n i f i c a n c e a t p < .05 i n o v e r a l l d i s c r i m i n a t i o n , group s e p a r a t i o n i n the reduced space 2 i s not s i g n i f i c a n t (as shown by D = .025 w i t h an F r a t i o of .575). The s c a l e d d i s c r i m i n a n t v e c t o r s show t h a t , taken as a system, the r e l a t i v e importance of o u t - o f - p o c k e t expenses and r e s i d e n t i a l t r a v e l time i n c r e a s e s (Table X L I I ) . Although the l e v e l of s i g n i f i c a n c e i s low, i t appears t h a t a l l f a c t o r s but bus frequency are important. T h i s supports the i d e a t h a t bus s e r v i c e s and c a r ownership are n e g a t i v e l y r e l a t e d . The l i n e a r d i s c r i m i n a n t f u n c t i o n s f o r s i n g l e c a r ownership and f o r the m u l t i p l e c a r ownership groups r e s p e c -t i v e l y , a r e : 202. Table XL CAR OWNERSHIP GROUP MEANS AND STANDARD DEVIATIONS FOR SINGLE AND MULTIPLE CAR OWNERSHIP CATEGORIES VARIABLE SINGLE* MULTIPLE** GROUP MEANS AVERAGE X 1(OTT) 1.110 .943 1.022 X 2(OPE) 3.008 2.302 2.633 X 3(TTO) .467 .300 .378 X^(FREQ) 4.394 4.348 4.370 X e(PKCHG) o .576 .594 . 586 GROUP STANDARD DEVIATIONS AVERAGE X^OTT) .6 20 .515 .572 X 2(OPE) 13.055 8.307 10.790 X 3(TTO) .937 .676 - .812 X^(FREQ) 2.592 3.225 2.942 X 5(PKCHG) .721 .649 .683 *Sample **Sample = 218 = 247 203. T a b l e X L I S T A T I S T I C A L TESTS OF THE PROPENSITY OF CAR OWNERSHIP GROUPS TO SH I F T MODE UNIVARIATE F-TESTS FOR CAR OWNERSHIP VA R I A B L E F-RATIO F P X ^ O T T ) 10.04 .001 X 2 ( O P E ) .50 n. s X 3 ( T T O ) 4.90 .05 X (FREQ) .03 n.s X c ( P K C H G ) .08 n.s S I G N I F I C A N C E OF DISCRIMINATOR AND GROUP SEPARATION A = .9704 D 2 = .02512 *1 = 5.0 F ^ 5 9 = .575 F 2 = 459.0 F„„ = 2.801 F = n.s H2 P F < .05 P R 2 = .029 • S I G N I F I C A N C E OF ROOTS  R o o t X. % o f No. o f Z o f 2 2 T r a c e R o o t s R o o t s d . f . x X P o s s i b l e P 1 .0305 99.99 5 .0305 5 28.3 .001 204. T a b l e X L I I VECTOR LOADINGS ON DISCRIMINATOR VARIABLE SCALED VECTOR X 1(OTT) 9.73 X 0(OPE) 8.92 X 3(TTO) 8.52 X 4(FREQ) -0.52 X 5(PKCHG) -2.06 z = -1.920 + 3.460X.. s 1 z = -1.387 + 2.940X, m 1 These are r e l a t i v e l y i n e f f e c t i v e i n c l a s s i f y i n g c a r ownership group w i t h 46.4 p e r c e n t misses (Table X L I I I ) . The F r a t i o of Table XLIII PREDICTED CLASSIFICATION VERSUS ACTUAL GROUP MEMBERSHIP NUMBER PREDICTED TO BE IN GROUP SINGLE MULTIPLE TOTAL MISSES ACTUAL NUMBER SINGLE 28 190 218 190 IN GROUP MULTIPLE 21 226 247 21 465 I T T % MISCLASSIFIED = 4 6 . 4 % 205, 10.04 f o r the s i n g l e o v e r a l l t r a v e l time i n the reduced space 2 i s s i g n i f i c a n t a t p < .002 but R = .15 and R = .02 show t h a t c s t r a t i f i c a t i o n by c a r ownership f o r mode s h i f t p r o p e n s i t y i s f o r a l l p r a c t i c a l purposes unnecessary (Table XLIV). Table XLIV SIGNIFICANCE OF DISCRIMINATOR USING ONLY SIGNIFICANT VARIABLES F J 6 3 =. 10.04 F < .002 P R = .15 c R 2 = .021 In view of these r e s u l t s i t was f e l t t h a t a s t r a t i f i -c a t i o n i n t o 3 groups would be more r e l e v a n t . T h e r e f o r e the a p r i o r i groups t e s t e d were those w i t h one c a r , two c a r s and th r e e or more c a r s . T a b l e XLV shows the r e s u l t s , and i n d i c a t e s t h a t the dichotomy i n t o s i n g l e and m u l t i p l e i s v a l i d , although adding the t h i r d group (three or more cars) i n c r e a s e s the impor-tance of r e s i d e n t i a l t r a v e l time, thereby showing some r e l u c -tance of the th r e e c a r f a m i l i e s t o s h i f t u n l e s s p a r k i n g i s very c l o s e l y i n t e g r a t e d with the t r a n s i t s t a t i o n i n the park and r i d e system. 206. Table XLV TESTS ON CAR OWNERSHIP USING 3 GROUPS COEFFICIENTS OF DISCRIMINANT FUNCTIONS VARIABLE ONE TWO THREE OR CAR* CARS** MORE CARS*** X 1(OTT) 3.399 2.864 3.131 X 3(TTO) .520 .242 .572 CONSTANT -2.008 -1.362 -1.747 SIGNIFICANCE OF FIRST CANONICAL VARIATE 2 F = r 4 6 2 5.50 F < .005 P R .19 C R 2 = .03 PREDICTED CLASSIFICATION VERSUS ACTUAL GROUP MEMBERSHIP NUMBER PREDICTED TO BE IN GROUP ONE TWO THREE+ TOTAL MISSES 28 146 44 218 190 16 160 33 209 49 5 25 8 38 30 465 267 % MISCLASSIFIED = 57.7% ACTUAL NUMBER ONE IN GROUP TWO THREE •Sample = **Sample = ***Sample = 218 209 38 207. Income as a F a c t o r i n P r o p e n s i t y to S h i f t Mode Four c a t e g o r i e s of income were t e s t e d : very low (>$4,000), low ($4-8,000), medium ($8-12,000), and h i g h (<$12,000) The t e s t s show s i g n i f i c a n t s e p a r a t i o n of the f o u r groups on the dimensions of o v e r a l l t r a v e l time, r e s i d e n t i a l t r a v e l time, and o u t - o f - p o c k e t expenses. O b s e r v a t i o n of the v a r i a t e means f o r o v e r a l l t r a v e l times show t h a t a 7-10 p e r c e n t decrease i n o v e r a l l t r a v e l time would be s u f f i c i e n t to cause a s h i f t below incomes of $12,000 (Table XLVI). The mean f o r h i g h incomes (<$12,000) a t an index l e s s than 1 shows t h a t t h i s group would t o l e r a t e , on the average, g r e a t e r o v e r a l l t r a v e l times i f , presumably, o t h e r c h a r a c t e r i s t i c s make up f o r i t . In t h i s case i t appears t h i s group would demand a more f r e q u e n t s e r v i c e as a t r a d e - o f f . The h i g h e r income group would a l s o demand lower o v e r a l l o u t - o f - p o c k e t c o s t s , as would the medium income group. On the oth e r hand, medium and h i g h e r income groups would t o l e r a t e some walking between p a r k i n g l o t and t r a n s i t v e h i c l e , i n c o n t r a s t t o the lower income groups. On the o t h e r hand, f o r the p a r k i n g charge v a r i a b l e the very low income groups are s e n s i t i v e to i n c r e a s e d p a r k i n g charges i n t h a t o n l y s m a l l i n c r e a s e s would cause a s h i f t . Low income groups group s h i f t w i t h a d o u b l i n g of the p a r k i n g f ee as would middle income groups, whereas h i g h income groups would be somewhat more s e n s i t i v e . 208. Table XLVI INCOME GROUP MEANS AND STANDARD DEVIATIONS FOR VERY LOW, LOW, MEDIUM, AND HIGH INCOME CATEGORIES VARIABLE VERY LOW** MEDIUM*** HIGH**** LOW* GROUP MEANS AVERAGE Xj^ (OTT) 1.105 1.071 1.082 .899 1.022 X 2(OPE) 1.313 1.787 3.136 2.940 2.633 X 3(TTO) .714 .605 .291 . 243 .378 X 4(FREQ) 3 .579 4.206 4.427 4.544 4.370 X 5(PKCHG) 1.043 .553 .529 .621 . 586 GROUP ' STANDARD DEVIATIONS AVE RAG] X±(OTT) .567 .524 .646 .503 .572 X 2(OPE) 1.029 6.677 14.518 9.159 10.790 X 3(TTO) 1.043 1.035 .688 .634 .812 X 4 (FREQ) 2.835 2.473 2.978 3.266 2.942 X c(PKCHG o 1.301 .530 . 588 .766 .683 *Sample = 19 **Sample = 126 ***Sample = 171 ****Sample = 149 209. The s t a t i s t i c a l t e s t s show an o v e r a l l d i s c r i m i n a t i o n a t p < .001 with a l l t h r e e r o o t s s i g n i f i c a n t (Table X L V I I ) . Most important v a r i a b l e s are o v e r a l l t r a v e l time, o u t - o f - p o c k e t . expenses (as shown by the s c a l e d v e c t o r l o a d i n g s ) and r e s i -d e n t i a l t r a v e l time (Table X L V I I I ) . P a r k i n g charge i s a l s o s i g n i f i c a n t i n the e x p l a n a t i o n o f the d i f f e r e n c e s between the income c l a s s e s . A l l groups are se p a r a t e d from each o t h e r on 2 these dimensions as shown by the D m a t r i x and i t s accompanying F Q 2 r a t i o s (Tables XLIX and L ) . The f o l l o w i n g l i n e a r d i s c r i -minant f u n c t i o n s f o r very low, low, medium and h i g h incomes r e s p e c t i v e l y are used to c a l c u l a t e the d i s c r i m i n a n t scores and the p o s t e r i o r c l a s s i f i c a t i o n s . These are, r e s p e c t i v e l y : z „ = -3.150 + 3.133X, + 0.934X o + 2.080X-vJc, 1 3 . 5 z„ = -2.194 + 3.145X, + 0.761X, + 1.009X-% 1 3 5 z = -2.043 + 3.242X, + 0.263X-, + 0.950X C m 1 3 5 z = -1.592 + 2.660X, + 0.223X- + 1.180X-n 1 3 5 The r e s u l t i n g p o s t e r i o r c l a s s i f i c a t i o n w i t h 62.2 p e r c e n t misses appears very crude (Table L I ) . However, s i n c e the assignment i s based on the group w i t h the h i g h e s t p r o b a b i l i t y of member-s h i p w i t h no allowance f o r suspended judgment, the more groups th e r e are the lower e x p e c t a t i o n of a c c u r a t e c l a s s i f i c a t i o n . Under these circumstances the accuracy i s c o n s i d e r e d r e a s o n a b l e . 210. Table XLVII STATISTICAL TESTS OF THE PROPENSITY OF INCOME GROUPS TO SHIFT MODE UNIVARIATE F-TESTS FOR INCOME VARIABLE F-RATIO F p X 1(OTT) 3.46 <.05 X 2(OPE) .52 n.s X 3(TTO) 6.61 <.001 X^(FREQ) .78 n.s X c(PKCHG 3.53 <.05 SIGNIFICANCE OF DISCRIMINATORS A = .9013 F l = 15.0 F 1 2 = 1262.0 F rH2 = 3.227 F P R 2 < .001 = .096 SIGNIFICANCE OF ROOTS No. of X. % of No. P o s s i b l e E 2 Roots 1 Trace Roots Roots d . f . x X 1 .0674 63.27 5 .1065 15 198.0 < .001 2 .0291 27.30 4 .0391 8 72.5 < .001 3 .0100 9.43 3 .0100 3 18.6 < .001 Table XLVIII VECTOR LOADINGS ON DISCRIMINATORS VARIABLES SCALED VECTORS I I I I I I X±(OTT) - 3 . 5 0 - 7 . 8 2 8 . 2 5 X 2(OPE) 1 0 4 . 7 1 - 2 8 . 0 6 5 2 . 0 6 X 3(TTO) - 1 4 . 3 8 . 3 6 - 7 . 8 8 X^ (FREQ) 1 2 . 1 4 1 . 7 5 - 2 0 . 9 7 X,. (PKCHG) - 3 . 8 0 1 1 . 7 2 6 . 9 9 Table XLIX SIGNIFICANCE OF GROUP SEPARATION D Z MATRIX VLO LO MED LO . 1 1 3 3 MED . 3 4 3 6 . 1 1 7 8 HI . 3 4 3 1 . 1 2 1 8 . 2 1 1 6 F-RATIO MATRIX VLO LO MED LO 5 . 2 3 MED 1 6 . 0 0 5 . 4 1 HI 1 5 . 9 0 5 . 6 3 9 . 7 8 . 0 0 1 i n a l l cases Table L SIGNIFICANCE OF DISCRIMINATORS USING ONLY SIGNIFICANT VARIABLES F459 = 4 ' 4 2 F .001 P F-PROB MATRIX VLO LO MED LO .031 MED .003 .010 HI .004 .000 .017 CANONICAL CORRELATION FOR EACH ROOT R , = .22 c l R c 2 = .17 R 0 = .09 c3 Table LI PREDICTED CLASSIFICATION VERSUS ACTUAL GROUP MEMBERSHIP PREDICTED vr.n T.n \ ACTUAL VLO LO MED HI TOTAL MISSES VLO 7 4 4 4 19 12 LO 23 21 39 43 126 105 MED 15 17 70 69 171 101 HI 10 18 43 78 ' 149 465 71 289 % MISCLASSIFICATION = 62.2% 213. Occupation as a F a c t o r i n P r o p e n s i t y t o S h i f t Mode S i x o c c u p a t i o n groups were examined: m a n a g e r i a l , p r o f e s s i o n a l , s e c r e t a r i a l , c l e r i c a l , s a l e s and o t h e r (Table L I I ) . O v e r a l l d i s c r i m i n a t i o n was s i g n i f i c a n t i n the 5 v a r i -a b l e s s t u d i e d w i t h 4 r o o t s s i g n i f i c a n t a t l e a s t a t p < .01 (Table L I I I ) . Large v a r i a t i o n s i n the v a l u e s f o r o u t - o f - p o c k e t expenses show t h a t managers and p r o f e s s i o n a l employees demand s u b s t a n t i a l r e d u c t i o n i n expenses w h i l e s e c r e t a r i e s and c l e r k s are reasonably s a t i s f i e d w i t h the e x i s t i n g c o s t of s e r v i c e ( i . e . , p a r k i n g c o s t ) . S a l e s employees and o t h e r employees which i n c l u d e craftsmen and l a b o u r e r s show a s u b s t a n t i a l d e s i r e t o have expenses very much lower than they c u r r e n t l y e x p e r i e n c e . How-ever, these v a r i a n c e s do not prove to be s i g n i f i c a n t because o f the extreme val u e s w i t h i n some groups. The standar d d e v i a -t i o n s f o r the l a t t e r two groups i s very high as w e l l as substan-t i a l d e v i a t i o n s w i t h i n the managerial and p r o f e s s i o n a l c l a s s e s . Some o c c u p a t i o n a l groups appear to be prepared to walk s u b s t a n t i a l l y g r e a t e r d i s t a n c e s a t the t e r m i n a l , p a r t i c u -l a r l y s e c r e t a r i e s and s a l e s p e o p l e . Craftsmen and l a b o u r e r s are u n w i l l i n g to walk very much f u r t h e r than a t p r e s e n t w h i l e managers and p r o f e s s i o n a l workers w i l l walk some i n c r e a s e d d i s t a n c e . S e c r e t a r i e s are the most s e n s i t i v e to i n c r e a s e s i n p a r k i n g f e e i n c r e a s e s , w h i l e c l e r k s are the l e a s t s e n s i t i v e . 214 . Table L I I OCCUPATION GROUP MEANS AND STANDARD DEVIATIONS FOR MANAGERS, PROFESSIONALS, SECRETARY, CLERICAL, SALES, AND OTHER OCCUPATIONAL CATEGORIES* VARIABLE MANG. PROF. SEC. CLER. SALES OTHER GROUP MEANS AVERAGE X±(OTT) 1 .006 1.040 1.176 1 .114 .904 .879 1.022 X 2 (OPE) 2 .276 2.849 1.267 1 .037 4.778 4 .867 2.633 X 3(TTO) .346 .319 .299 .515 .195 .836 .378 X^ (FREQ) 4 .097 4 .787 4.176 4 .023 5.238 3 .636 4.370 X c(PKCHG) .622 .516 .969 .407 .658 .760 .586 GROUP STANDARD DEVIATIONS AVERAGE X 1(OTT) .619 .497 .529 .690 .539 .545 . 572 X 2(OPE) 7 .965 11.351 1.057 1 .087 16.119 21 .596 10.790 X 3(TTO) .782 .669 .585 1 .121 '. 510 1 .221 .812 X^(FREQ) 2 .842 3.169 2.675 2 .387 3.491 2 .369 2.942 X 5(PKCHG) .778 .501 1.021 .348 .389 1 .058 .683 *Sample S i z e s : Ma'ng. = 176 P r o f . = 174 Sec. = 17 C l e r . = 44 Sa l e s = 21 Other = 33 2 1 5 . T a b l e L I I I STATISTICAL TESTS OF THE PROPENSITY OF OCCUPATION GROUPS TO SHIFT MODE UNIVARIATE F-TESTS VARIABLE F -RATIO F P Xj^ (OTT) 1.13 n. s X 2(OPE) .75 n. s X 3(TTO) 2.89 < .05 X^(FREQ) 1.94 n. s X c(PKCHG) o 2.66 < .05 SIGNIFICANCE OF DISCRIMINATORS A = .9050 F l = 25.0 F 2 = 1691.75 F H2 = 1.84 F P < .01 R 2 = .091 SIGNIFICANCE OF ROOTS [o. X. l % P o s s i b l e Roots EX . l d . f . 2 X 2 x p 1 .0508 49 .98 5 .1017 20 235.0 < .001 2 .0266 26.14 4 .0509 12 118.0 < .001 3 .0197 19.41 3 .0243 6 56.5 < .001 4 .0045 4.46 2 .0045 2 10.4 < .01 5 .0000 .01 1 .0000 - - n.s 216. Labourers, s a l e s people, and managers are a l l above average i n s e n s i t i v i t y to p a r k i n g f ee increases< The s c a l e d v e c t o r a s s o c i a t e d w i t h the f i r s t r o o t shows t h a t bus frequency f o l l o w e d by p a r k i n g c o s t and r e s i d e n -t i a l t r a v e l time are important c o n s i d e r a t i o n s f o r the v a r i o u s o c c u p a t i o n groups to s h i f t mode.(Table L I V ) . Table LIV VECTOR LOADING ON DISCRIMINATORS VARIATES SCALED VECTORS I I I I I I IV V X x(OTT) -3.51 3.59 -7.73 -5.63 -5.77 X 2(OPE) -12.11 -62.33 110.88 18.50 -192.14 X 3(TTO) 11.43 7.98 4.53 -8.19 3.87 X^(FREQ) -28.64 -14.09 26.06 -39.17 26.49 X C(PKCHG) 7.04 -10.79 -5.12 -3.79 1.85 Mahalanobis D and the. a s s o c i a t e d F p r o b a b i l i t y show t h a t the s e p a r a t i o n of a l l groups i s s i g n i f i c a n t a t p < .001 (Table L V ) . The d i s c r i m i n a n t f u n c t i o n s are r e s p e c t i v e l y : z = -0.514 + 0.533X, + 1.357X.. m 1 5 z = -0.369 + 0.492X, + 1.126X C p 1 5 z = -1.093 + 0.459X, + 2.115X C sec 1 5 217 . •0.386 + 0.790X, + 0.887X.. X D z , = -0.503 + 0.300X, + 1.438X C s l e s 1 5 z = -1.169 + 1.291X, + 1.656X C O 1 5 Table LV SIGNIFICANCE OF GROUP SEPARATION D MATRIX MANG. PROF. SEC. CLER. SALES PROF. .31 SEC. .71 1.80 CLER. 1.06 2.37 .05 SALES 4.55 2.60 8 .71 9.92 OTHER 4.68 3.06 9.02 10.15 .48 F-RATTO MATRIX MANG. PROF. SEC. CLER. SALES PROF. 14.35 SEC. 32.80 83.20 CLER. 49.00 110.00 2.32 SALES 210.00 120 .50 404.00 460.00 OTHER 217.50 141.50 418.00 470.00 27.20 F < .001 i n a l l cases P Using these f u n c t i o n s the p o s t e r i o r c l a s s i f i c a t i o n shows 79.8 p e r c e n t m i s c l a s s i f i c a t i o n s (Table L V I ) . Again, the number of groups a f f e c t s t h i s poor assignment, but i t must be concluded t h a t o c c u p a t i o n has a very weak i n f l u e n c e on an i n d i v i d u a l s 218. p r o p e n s i t y to s h i f t modes. The s i g n i f i c a n c e o f the d i s c r i m i n a -t i o n u s i n g o n l y the s i g n i f i c a n t v a r i a b l e s i n the d i s c r i m i n a n t f u n c t i o n s i s shown i n Ta b l e L V I I . T a b l e LVI PREDICTED CLASSIFICATION VERSUS ACTUAL GROUP MEMBERSHIP PREDICTED MANG. PROF. SEC. CLER. SALES OTHER MISSES MANG. 4 46 33 8 56 29 172 PROF. - 65 36 10 36 27 109 SEC. - 6 4 1 3 3 13 CLER. - 19 6 2 9 8 42 SALES - 6 4 0 8 3 13 OTHER - 10 6 4 2 11 22 % MISCLASSIFIED = 79.8% 371 T a b l e LVII SIGNIFICANCE OF DISCRIMINATORS USING ONLY SIGNIFICANT VARIABLES „2 458 = 2.77 < .05 F-PROBABILITY MATRIX MANG. PROF. SEC. CLER. SALES PROF. .331 SEC. .126 .031 CLER. .077 .223 .010 SALES .707 .534 .348 .120 OTHER .004 .001 .048 .018 .015 CANONICAL CORRELATION FOR FIRST TWO ROOTS; c l C2 185 156 2 1 9 . PRINCIPAL FINDINGS I t was p o s t u l a t e d t h a t one p u b l i c o b j e c t i v e to r a t i o n a l i z e modal balance i s to decrease the use of automobiles and i n c r e a s e the use of some more e f f i c i e n t system from the c r i t e r i o n of p u b l i c w e l f a r e . A p l a n n i n g t o o l i n the form of a q u a s i - p r e d i c t i v e model was developed which would a l l o w an assessment of the r e s u l t s of c r e a t i n g a park and r i d e system, and the i n c r e a s e of p a r k i n g c o s t s i n the CBD on the modal balance of the c o r r i d o r ; s p e c i f i c a l l y the number of c a r d r i v e r s who would s h i f t t o a new system. The model a l s o allows us to determine what socioeconomic groups would be more s e n s i t i v e to changes i n the t r a n s p o r t a t i o n system. The a n a l y s i s has shown t h a t i n c r e m e n t a l p o l i c y changes r e g a r d i n g the supply, l o c a t i o n , and charges f o r p a r k i n g , along w i t h an i n t e g r a t e d t r a n s i t f a c i l i t y i n the c o r r i d o r may have dramatic e f f e c t s on changing the mode s p l i t . Although t h i s a n a l y s i s was of the development and f e a s i b i l i t y o f the model and p l a n n i n g approach, and not o f s i m u l a t i o n t e s t s , some of the e f f e c t s can be i n -f e r r e d . The r e s u l t s j u s t i f y the concern of t r a n s p o r t a t i o n p l a n n e r s w i t h t r a v e l time. I f a park and r i d e system c o u l d be developed which would reduce the o v e r a l l t r a v e l time by o n l y a modest amount i t would have a s i g n i f i c a n t e f f e c t on the number of persons who would s h i f t t o the system. The r e s u l t s i n the 220 . c o r r i d o r s t u d i e d here are probably c o n d i t i o n e d by the f a c t t h a t the North Shore p o p u l a t i o n do not seem adverse to bus t r a v e l i f the s e r v i c e i s c o m p e t i t i v e , as i t i s f o r many persons i n t h i s a r e a . In p r a c t i c e t h i s decrease i n t r a v e l time would be very d i f f i c u l t to achieve under a l l c i r c u m s t a n c e s . T h i s i s f u r t h e r compounded by the f a c t t h a t any multimodal system would need to be almost time-continuous w i t h o u t a s u b s t a n t i a l w a i t f o r a t r a n s i t v e h i c l e . T r a n s i t frequency w i t h i n the over-a l l system was shown to be the most important f a c t o r i n a c o n s i d e r a t i o n of t h i s type of system. However, the f r e q u e n c i e s •demanded f o r a s u b s t a n t i a l s h i f t are not u n r e a l i s t i c w i t h . a frequency of 4.5 minutes a c h i e v i n g s u b s t a n t i a l s u c c e s s . Subway headways i n l a r g e r c i t i e s are u s u a l l y l e s s than h a l f of t h i s v a l u e i n rush p e r i o d s , and t h e r e f o r e g i v e n a s u f f i c i e n t c a p a c i t y i n the f e e d e r system (roads, p a r k i n g , and f e e d e r buses) such a system appears f e a s i b l e . The t e s t s show t h a t d r i v e r s w i l l t o l e r a t e some walking i n the system. The mean w a l k i n g d i s t a n c e s p r e f e r r e d f o r a s h i f t of j u s t over 2 minutes i s w e l l w i t h i n the u s u a l w a l k i n g d i s t a n c e s most m o t o r i s t s f a c e i n o t h e r c i r c u m s t a n c e s . For l a r g e c i t i e s up to 5 minutes a t the d e s t i n a t i o n end, and somewhat . l e s s than 10 minutes a t the o r i g i n end, although l i t t l e i s known about t h i s a spect of a m o t o r i s t s walking t o l e r a n c e . I t i s h i g h l y l i k e l y t h a t i f these were put t o g e t h e r , however, t h a t the t o t a l of 15 minutes i s i n t o l e r a b l e , although, i n Chapter I I I i t was shown t h a t almost 32 p e r c e n t of those going by c a r walked 10 or more minutes a t the t r i p d e s t i n a t i o n . One f a c t o r to c o n s i d e r i n t h i s a n a l y s i s i s t h a t the t o l e r a b l e w a l k i n g d i s -tance a t the d e s t i n a t i o n i s unknown, and t h i s , i f i t had been asked might have i n v o l v e d a t r a d e - o f f w i t h the r e s i d e n t i a l walking d i s t a n c e and thereby decreased the l a t t e r . Judging by the r e s u l t s of Tab l e XIV, Chapter I I I , which shows substan-t i a l numbers of c a r d r i v e r s w a l k i n g more than 5 minutes a t t r i p d e s t i n a t i o n and t h a t t r a n s i t passengers are i n g e n e r a l d e p o s i t e d c l o s e r to d e s t i n a t i o n (as would the park and r i d e system), i t seems l i k e l y t h a t a two minute walking d i s t a n c e a t the p a r k i n g - t r a n s i t i n t e r f a c e would not cause a problem i n encouraging the use of the system. The i n s e n s i t i v i t y of o u t - o f - p o c k e t c o s t s i n the manner of combined bus f a r e and p a r k i n g c o s t i s d i f f i c u l t to i n t e r p r e t . Most s t u d i e s have shown t r a n s i t f a r e decreases to have l i t t l e e f f e c t on d i v e r t i n g c a r d r i v e r s . On the o t h e r hand, p a r k i n g c o s t i s u s u a l l y found t o be a s e n s i t i v e f a c t o r . One explana-t i o n i s t h a t the respondent p e r c e i v e d t h i s expense more i n the manner of an over the road c o s t (which i s u s u a l l y not a s t r o n g i n c e n t i v e to s h i f t ) , as he would v e h i c l e o p e r a t i n g c o s t o r t r a n s i t f a r e . In p r a c t i c e t h i s i s not an u n r e a l i s t i c explana-t i o n s i n c e some park and r i d e systems have a f e e which i s p a i d on p a r k i n g , but which i n c l u d e s the t r a n s i t p o r t i o n of the f a r e ( f o r example, the Toronto T r a n s i t Commission). The d r i v e r may see t h i s as an i n t e g r a t e d t r i p f a r e . As expected p a r k i n g charges i n the CBD would be an e f f e c t i v e means of b a l a n c i n g the mode s p l i t . Whether the charge i s l e v i e d as a f e e i n c r e a s e or as a tax would not a f f e c t the r e s u l t s s i n c e the important a s p e c t of the f a c t o r i s t h a t i t i s not a hidden c o s t , such as v e h i c l e o p e r a t i n g c o s t s . T h i s appears to be a f r u i t f u l area i n which to pursue ways of r a t i o n a l i z i n g mode b a l a n c e . An important f i n d i n g of t h i s chapter i s t h a t s o c i o -economic s t r u c t u r e e x e r t s a s i g n i f i c a n t i n f l u e n c e on what d i -mensions an i n d i v i d u a l w i l l p l a c e r e l a t i v e v a l u e i n h i s s e n s i -t i v e n e s s to s h i f t mode. In g e n e r a l those over 40, from f a m i l i e s with more than one c a r , wit h middle t o h i g h e r incomes, i n the n o n - p r o f e s s i o n a l occupations would be more r e s i s t a n t to s h i f t than the p o p u l a t i o n as- a whole. The age f a c t o r i n f l u e n c e s mode s h i f t p r o p e n s i t y through o u t - o f - p o c k e t expenses and frequency of s e r v i c e . Car ownership i s an i n f l u e n c e because of o v e r a l l t r a v e l time and r e s i d e n t i a l walking time. T h i s i s pro b a b l y a s p a t i a l e f f e c t as w e l l w i t h c a r ownership i n c r e a s i n g as d i s t a n c e from the CBD i n c r e a s e s , thereby p o i n t i n g up the t r a d e - o f f b e t -ween t r a v e l time and owning another c a r . Income i n f l u e n c e s are v a r i e d . The lower income groups are more time s e n s i t i v e than the high income groups, although the l a t t e r group are more s e n s i t i v e to t r a n s i t f r e q u e n c i e s and o u t - o f - p o c k e t c o s t s . On the oth e r hand, lower income groups would t o l e r a t e l e s s w a l k i n g than the h i g h e r income groups, and are more s e n s i t i v e to p a r k i n g charge i n c r e a s e s . 2 2 3 . T h e r e s u l t o f o c c u p a t i o n a s a n i n f l u e n c e o n s h i f t p r o p e n s i t y i s n o t c o n c l u s i v e , a l t h o u g h s o m e t e n d e n c i e s e m e r g e . S a l e s p e o p l e a n d t h e l o w e r s t a t u s g r o u p s a r e s e n s i t i v e t o c o s t f a c t o r s , w h i l e s e c r e t a r i e s a n d c l e r k s a r e n o t . U n e x p e c t e d l y m a n a g e r i a l a n d p r o f e s s i o n a l e m p l o y e e s a l s o a p p e a r t o b e c o s t s e n s i t i v e . P a r a d o x i c a l l y s e c r e t a r i e s a n d c l e r k s a r e p a r k i n g c h a r g e s e n s i t i v e , t h e e x p l a n a t i o n i s p r e s u m a b l y t h a t a g a i n f a r e a n d p a r k i n g c o s t c o m b i n e d i s p e r c e i v e d a s a l i n e t r a v e l c o s t w h i l e p a r k i n g i s n o t . CHAPTER VI MAJOR CONCLUSIONS, IMPLICATIONS OF FINDINGS, AND FURTHER RESEARCH There appears to be a r a t i o n a l e f o r p l a n n i n g an a p p r o p r i a t e mix of t r a n s i t and highway f a c i l i t i e s t o r a t i o n -a l i z e flows on the system, which w i l l reduce u n d e s i r a b l e s o c i a l consequences. Commuters make mode c h o i c e d e c i s i o n s a c c o r d i n g t o t h e i r socioeconomic s t a t u s which a l s o determines the r e l a t i v e v a l u e g i v e n by i n d i v i d u a l t r i p makers to time, c o s t , and convenience f a c t o r s . The a p p r o p r i a t e mix of f a c i l i -t i e s i s t h a t which o p t i m i z e s the t r a v e l h a b i t s and p r e f e r e n c e s of the u s e r s . The p l a n n i n g of such a mix i s p r e d i c a t e d on u n d erstanding the r e l a t i o n s h i p between socioeconomic s t r u c t u r e and t r a v e l p r e f e r e n c e s and thereby a d j u s t i n g the system so t h a t p u b l i c b e n e f i t s are maximized. T h i s c r i t e r i o n assumes t h a t each t r i p maker w i l l have a v a i l a b l e t h a t combination of s e r -v i c e s which he d e s i r e s . While i t i s not p o s s i b l e t h a t t h i s range of c h o i c e can be p r o v i d e d , some o p t i m i z a t i o n can be a c h i e v e d by a d j u s t i n g the s e r v i c e l e v e l s of each mode. How-ever, to p r o v i d e f o r an i n c r e a s e d l e v e l of s a t i s f a c t i o n f o r a l l commuters may i n c r e a s e s o c i a l c o s t s . For example, i f i n the extreme case a l l commuting was done by automobile the l e v e l o f s a t i s f a c t i o n of users may be i n c r e a s e d , but a t s u b s t a n t i a l 225. s o c i a l c o s t s . T h e r e f o r e , the primary c r i t e r i o n f o r mode s p l i t adjustment i s t h a t t r a v e l demands be met, but w i t h i n a l i m i t i n g c o n s t r a i n t p r o v i d e d by s o c i a l o b j e c t i v e s . Recent concern f o r the r e v i t a l i z a t i o n of p u b l i c t r a n s p o r t a t i o n has been f o r the purpose of c r e a t i n g i n c r e a s e d p u b l i c b e n e f i t s by way of more e f f i c i e n t l a n d use p a t t e r n s , economic e f f i c i e n c y , and s o c i a l c o n d i t i o n s of an urban r e g i o n . I f t h ere are no r e l a t i v e changes i n system flows there w i l l be no changes i n these p u b l i c b e n e f i t s . T r a d i t i o n a l a n a l y ses of mode s p l i t have shown t h a t we can expect l i t t l e s h i f t from auto-mobile commuting t o p u b l i c t r a n s p o r t a t i o n w i t h the simple imp-rovement of l i n e h a u l t r a n s i t systems. Rapid t r a n s i t improve-ments where they have been c a r r i e d out i n North America have a h i s t o r y of o p e r a t i n g s u c c e s s f u l l y only a t the expense of the r e s t of the t r a n s i t system, r a t h e r than as an a t t r a c t i o n f o r automobile commuters. In Toronto f o r i n s t a n c e , w h i l e subway revenue passengers i n c r e a s e d from 35.2 m i l l i o n i n 1955 ( i t s f i r s t f u l l y e a r of ope r a t i o n ) to 75.8 m i l l i o n i n 1967,* the r a t i o of t r a n s i t revenue passengers to metro p o p u l a t i o n dec-reased from. 240 to 167 d u r i n g t h a t period."'" The subway ( s e r v i n g the CBD) i n c r e a s e was accompanied by a decrease i n t o t a l t r a n s i t patronage, w h i l e the number of persons coming 2 downtown by automobile i n c r e a s e d . These trends i n Toronto and the absence of s u b s t a n t i a l p r o j e c t i o n s of a s h i f t from • I n c l u d i n g the B l o o r - D a n f o r t h l i n e . 226. automobiles to the new r a p i d t r a n s i t system i n San F r a n c i s c o * has prompted Z e t t e l to remark t h a t : BARTS impacts w i l l depend...on conscious p o l i c y a c t i o n . 3 The c o n c l u s i o n Z e t t e l reaches i s t h a t BART w i l l not " i n e x o r a b l y " cause changes but r a t h e r t h a t BARTS e x i s t e n c e w i l l s t i m u l a t e p u b l i c a c t i o n . The t h e s i s of t h i s study i s t h a t s u c c e s s f u l p u b l i c p o l i c i e s to a f f e c t the balance between automobile t r a v e l and p u b l i c t r a n s p o r t a t i o n must contend w i t h two f a c t o r s ; the i n -cidenc e o f e f f e c t s of p o l i c y o p t i o n s , and some mechanism to s u c c e s s f u l l y c o n t r o l demand. S e v e r a l c o n c l u s i o n s about the i n c i d e n c e o f e f f e c t s of p o l i c i e s have come from the a n a l y s i s . INCIDENCE OF EFFECTS OF MODE SHIFT POLICIES I t has been shown t h a t the socioeconomic c h a r a c t e r i s -t i c s of commuters to the CBD are d i f f e r e n t from non-CBD com-muters . T h e r e f o r e p a r k i n g p o l i c i e s o r i e n t e d to changing the s t r u c t u r e of p a r k i n g i n the CBD w i l l a f f e c t the mode s p l i t d i f f e r e n t l y than those p o l i c i e s f o r non-CBD l o c a t i o n s . The d i f f e r e n c e s i n these has not been examined i n any depth i n the study except as a framework to study CBD o r i e n t e d t r i p s . * Z e t t e l concludes from the s t u d i e s done f o r BART t h a t "BARTS main source of patronage w i l l be r i d e r s who have been d i v e r t e d from o t h e r t r a n s i t systems" although there w i l l be an es t i m a t e d 3 20 0 automobiles removed from the trans Bay c r o s s i n g s i n the peak hour i n 1975. (See Ref. 3). 2 2 7 . However, i n changing the mode s p l i t by means of p o l i c i e s i n the CBD the r e s u l t a n t decrease i n c o n g e s t i o n on the s t r e e t s may encourage more through t r a f f i c . On the other hand CBD users may f i n d t h a t they can leav e home c l o s e r to a d e s i r a b l e time thus c r e a t i n g a peak hour as sharp, but not as prolonged as p r e v i o u s l y . T h i s would tend to d i s c o u r a g e generated through t r a f f i c and i n c r e a s e b e n e f i t s to u s e r s . Because of these un-known f a c t o r s i t i s not f e a s i b l e to es t i m a t e the r e l a t i v e impact of a s h i f t on CBD vs non-CBD t r a v e l , nor the d i f f e r e n -t i a l s o c i a l e f f e c t s r e s u l t i n g from t h i s . The a n a l y s i s of CBD t r a v e l shows t h a t h i g h s t a t u s o c c u p a t i o n a l groups are not adverse to u s i n g the bus mode. Th i s might be expected i n the'case study s i t u a t i o n . T r i p l e n g t h s are r e l a t i v e l y s h o r t , bus s e r v i c e i s good, and t r a f f i c c o n g e s t i o n i s heavy. The B r i d g e t r a f f i c i s a w e l l r e c o g n i z e d rush hour problem i n Vancouver and the r a t i o n a l i z a t i o n of these f a c t s appear to encourage many p r o f e s s i o n a l s to use the bus. On the o t h e r hand the low s t a t u s o c c u p a t i o n s appear t o be w i l l i n g t o put up w i t h c o n g e s t i o n to be a b l e to d r i v e downtown. Another f a c t o r i n the study was the apparent dichotomy w i t h i n the s o - c a l l e d " c h o i c e " r i d e r c a t e g o r y . I t appears t h a t automobile d r i v e r s can be c l a s s i f i e d i n t o those who have a n a l y -sed (to some extent) the advantages of bus t r a v e l , and those who have never c o n s i d e r e d i t as an a l t e r n a t i v e . T h i s l a t t e r group may be h i g h l y s u s c e p t i b l e to t r a n s i t marketing s t r a t e g i e s or such n e g a t i v e c o n t r o l s as p a r k i n g fee changes. I 2 2 8 . A p o l i c y mechanism w i l l a f f e c t users i n d i f f e r e n t ways depending on the r e l a t i v e values o f the system. Simple s o l u t i o n s such as lowering f a r e s (or r a i s i n g them) to r a t i o n -a l i z e the mode s p l i t s h ould c o n s i d e r the i n c i d e n c e of the e f f e c t s of the c o n t r o l s . The study has shown an i n t e r d e p e n -dence between the socioeconomic s t r u c t u r e of the t r i p maker and the way i n which the system a t t r i b u t e s are v a l u e d . Con-seq u e n t l y any changes i n the system w i l l not onl y e f f e c t the number of users of the system and the mode s p l i t , but a l s o the c h a r a c t e r i s t i c s of the c l i e n t group who use each mode. C o r r e l a t i o n t e s t s showed a s t r o n g interdependency between l e v e l of income and t r a v e l expenses when the c o r r e l a -t i o n between s t r u c t u r e and system a t t r i b u t e s i s maximized. Those of h i g h e r incomes have an a b i l i t y t o s e l e c t the more expensive a l t e r n a t i v e . T h i s i s as expected and has been seen i n the i n c r e a s e d ownership and use of automobiles as the g e n e r a l l e v e l of s o c i e t a l incomes has i n c r e a s e d . Of more i n t e r e s t i s the i n t e r d e p e n d e n c i e s of other s t r u c t u r a l v a r i a t e s w i t h system performance. Car.ownership and a v a i l a b i l i t y are r e l a t e d to excess t r a v e l times and the frequency of bus s e r v i c e . T h i s f o l l o w s i n t u i t i v e r e a s o n i n g . The d e c i s i o n to extend bus l i n e s i n t o new areas f o l l o w s development of these areas when th e r e i s a s u f f i c i e n t demand p e r c e i v e d to j u s t i f y these e x t e n s i o n s . * I f c a r ownership i s hig h demand f o r bus s e r v i c e i s low and *Some ex p e r i m e n t a t i o n w i t h p r o v i d i n g f u l l s e r v i c e to r e l a t i v e l y undeveloped suburban areas has been c a r r i e d out. (See Ref . 4) . • t h e r e f o r e s e r v i c e i s only p r o v i d e d when those who have no t r a n s p o r t a t i o n c h o i c e become a s i g n i f i c a n t group to warrant t r a n s i t s e r v i c e e i t h e r from p o l i t i c a l p r e s s u r e or economic i n c e n t i v e s . On the o t h e r hand where t r a n s i t s e r v i c e i s al r e a d y good, the need f o r a second or t h i r d c a r d i m i n i s h e s . I n f e r e n c e s are t h a t i f a h i g h q u a l i t y t r a n s i t s e r v i c e i s p r o -v i d e d to a d e v e l o p i n g area (such as the North Shore communities) the demand f o r such a s e r v i c e would cause a s w i t c h away from m u l t i c a r ownership. T h i s however would r e q u i r e a change i n the "pay as you go" p h i l o s o p h y of t r a n s i t d e c i s i o n making and would r e q u i r e s u b s i d i z a t i o n o f c a p i t a l and o p e r a t i n g expenses u n t i l demand i n c r e a s e d to economic l e v e l s . Moreover, changes i n the t r a n s p o r t a t i o n s e r v i c e w i l l have an impact on the s t r u c t u r e of the i n f l u e n c e area of the system. I f c e r t a i n r e s t r i c t i v e changes are made some people w i l l , i n the long run, move out of the i n f l u e n c e area ( i . e . , r e l o c a t e ) r a t h e r than f a c e the i n c r e a s e d d i s u t i l i t i e s of t r a v e l . On the o t h e r hand, o t h e r s who f i n d the new s e t of circumstances advantageous may l o c a t e to take advantage of the new s e r v i c e . In the long run t h e r e f o r e e q u i l i b r i u m w i l l occur between the socioeconomic s t r u c t u r e of a c o r r i d o r and the t r a n s p o r t a t i o n system s e r v i n g i t . T h i s study has assumed a f i x e d demand f o r t r a v e l t o c o n c e n t r a t e on the r e l a t i o n s h i p between s t r u c t u r e and modal b a l a n c e . F u r t h e r r e s e a r c h however i s needed to t r a c e the impact, not o n l y on the mode s p l i t but on the changes 230. i n socioeconomic composition of those u s i n g the system. The e x p e c t a t i o n i s t h a t d i f f e r e n t c o r r i d o r s d e f i n e d by t r a n s p o r -t a t i o n s e r v i c e would have d i f f e r e n t socioeconomic s t r u c t u r e . That i s , a c o r r i d o r s e r v e d p r i m a r i l y by a r t e r i a l s and bus w i l l have d i f f e r e n t socioeconomic c h a r a c t e r i s t i c s than one s e r v e d by freeways and r a p i d t r a n s i t . The e x t e n s i o n of the type of a n a l y s i s c a r r i e d out here would r e q u i r e the measurement over time of changes o c c u r r i n g w i t h t r a n s p o r t a t i o n p o l i c y i n p u t s . The i n t r o d u c t i o n of a multimode park and r i d e system i n t o a t r a n s p o r t a t i o n c o r r i d o r i s shown here to be v a l i d i n terms of r e d u c i n g the amount of automobile t r a f f i c e n t e r i n g the CBD. I f the proper combination of walk times, t r a n s i t f r e q u e n c i e s , and an o v e r a l l r e d u c t i o n i n t r a v e l time was f e a s i b l e a c o n c l u s i o n of t h i s study i s t h a t s u b s t a n t i a l s h i f t s would o c c u r . (However, s i n c e the s h i f t t o t r a n s i t would r e l i e v e c o n g e s t i o n and thereby, perhaps s u b s t a n t i a l l y , decrease d i s -u t i l i t i e s o f c a r d r i v i n g , a c o u n t e r v a i l i n g tendency would be to i n c r e a s e the use of the c o r r i d o r by generated t r a f f i c ) . * The i n c r e a s e i n o v e r a l l t r a v e l time needed to e f f e c t a s h i f t would probably r e q u i r e a r a p i d t r a n s i t l i n k so t h a t by i n c r e a s -i n g s u b s t a n t i a l l y the l i n e - h a u l speed, some impact on o v e r a l l time was e f f e c t e d . The major d i f f i c u l t y , however, appears not *There seems no easy s o l u t i o n to t h i s problem. M c G i l l i v r a y has suggested an a n a l y t i c a l procedure by e s t i m a t i n g the i n t e r d e p e n d e n c i e s between v a r i a b l e s and attempting to assess the e f f e c t s due to simultaneous changes i n two or more v a r i a b l e s . That i s , f o r example, t e s t a 30 p e r c e n t decrease i n t r a n s i t f a r e s c o n c u r r e n t l y w i t h an i m p l i e d 5 p e r c e n t i n c r e a s e i n road t r a v e l time. (See Ref. 5). to be i n terms of t r a n s p o r t a t i o n e f f i c i e n c y but r a t h e r i n the i n s t i t u t i o n a l s t r u c t u r e s needed to b r i n g about the necessary changes i n p o l i c y . PUBLIC INTEREST BENEFITS AND SYSTEM PERFORMANCE The s o c i a l o b j e c t i v e of p o l i c i e s to r a t i o n a l i z e the mode s p l i t or s p e c i f i c a l l y to c r e a t e a s h i f t t o t r a n s i t , i s to i n c r e a s e p u b l i c i n t e r e s t b e n e f i t s . T h i s i m p l i e s b a l a n c i n g demand wit h the c a p a c i t y of the f a c i l i t i e s by o p t i m i z i n g the use of the system. T h i s a n a l y s i s has suggested a framework and mechanism which w i l l e f f e c t a b a l a n c e d system p r o v i d i n g the c r i t e r i a f o r such a b alance are determined o u t s i d e the model. C u r r e n t i n t e r e s t among t r a n s p o r t economists i s on a p r i c e mechanism to get a more e f f e c t i v e use of t r a n s p o r t f a c i l i -t i e s . T h i s concern i s d i v i d e d between the use of p r i c e to r a t i o n the use of highways, and p r i c i n g to make t r a n s i t more a t t r a c t i v e . The economic premise behind p r i c i n g to r a t i o n the use of road space i s t h a t the t r a f f i c flows most b e n e f i c i a l to t r a f f i c as a whole are those l e v e l s a t which the c o s t of road use to each i n d i v i d u a l i s t h a t which takes i n t o account not only the c o s t to the i n d i v i d u a l but a l s o the c o s t he imposes on the whole t r a f f i c stream by c o n t r i b u t i n g to c o n g e s t i o n of the stream. When t h i s t o t a l c o s t ( i . e . , c o s t o f o p e r a t i o n of h i s v e h i c l e due to c o n g e s t i o n p l u s the i n c r e a s e d c o s t to o t h e r v e h i c l e s due to h i s i n c r e m e n t a l c o n t r i b u t i o n to congestion) equals bene-f i t s the stream w i l l become s t a b i l i z e d and t o t a l b e n e f i t s w i l l be maximized. 2 3 2 . Two problems however are ex t a n t i n a p r i c i n g mechanism f o r mode s p l i t adjustment. F i r s t , no p r a c t i c a l means of imple-menting charges has been found. Suggestions f o r c o n g e s t i o n p r i c i n g have been v e h i c l e meters w i t h computer b i l l i n g , ex-t e r n a l meters c h a r g i n g t r a f f i c f o r the l e n g t h of time i n c e r -t a i n areas such as the CBD, and a p a r k i n g charge or tax. While p a r k i n g charges are not p a r t i c u l a r l y s a t i s f a c t o r y t o c o n t r o l c o n g e s t i o n (because of v e h i c l e s going through the l i m i t e d area where c o n g e s t i o n p r i c i n g i s i n e f f e c t ) t h i s method appears t o have the most promise f o r mode s p l i t adjustment because o f i t s i m p o s i t i o n a t the t e r m i n a l o f the journey. The second problem w i t h p r i c i n g i s the apparent i n s e n s i t i v i t y of many to c o s t of t r a v e l . Consequently, mode s p l i t adjustment r e q u i r e s a mechan-ism which goes beyond p r i c i n g . The p r e s e n t study extends p r i c i n g ideas to i n c l u d e non-economic as w e l l as economic i n f l u e n c e s and to c o n s i d e r i n c i d e n c e of e f f e c t s . I f the mode c h o i c e i s a f u n c t i o n of system a t t r i b u t e s as demonstrated here then maximum s o c i a l bene-f i t s are gained when the use of the system i s such t h a t each t r i p maker i s a t the margin where h i s b e n e f i t s (or s a t i s f a c t i o n l e v e l s ) are j u s t e q u a l t o the c o s t s (or d i s b e n e f i t s ) i n c u r r e d on the system. Given a l e v e l of demand f o r t o t a l t r i p making and a continuous supply f u n c t i o n t h e r e w i l l be an adjustment between modes so t h a t everyone u s i n g the system w i l l maximize h i s b e n e f i t s r e l a t i v e to h i s c o s t s . R e l e a s i n g the r e s t r i c t i o n of a g i v e n demand f o r t r a v e l , t r i p making w i l l i n c r e a s e u n t i l maximum s o c i a l b e n e f i t i s r e a l i z e d . The quandry f a c e d by t r a n s i t management of uneconomic l e v e l s of demand stems from a m i s - i n t e r p r e t a t i o n of t h i s economic premise. The p r e s s u r e to lower f a r e s as a method of a t t r a c t i n g r i d e r s f o l l o w s the law of supply and demand. However, i t appears t h a t non-economic f a c t o r s such as a com f o r t a b l e r i d e i s an important determinant of demand f o r t r a n s i t , and low e r i n g the p r i c e o f t r a n s i t i n v a r i a b l y decreases revenues i n the long run, o r does not i n c r e a s e them enough to p r o v i d e a b e t t e r s e r v i c e l e v e l . T h e r e f o r e f a r e decreases are s e l f d e f e a t i n g . As L i s c o p o i n t s out the l a c k o f demand f o r t r a n s i t i s not because f a r e s are too hig h but p r e c i s e l y because they are too low, thus ca u s i n g underinvestment i n t r a n s i t f a c i l i t i e s and a consequent d e c l i n e i n q u a l i t y of s e r v i c e . Q u a l i t y of s e r v i c e which i n c -ludes comfort and convenience f a c t o r s as w e l l as time and c o s t f a c t o r s i s thereby a primary focus of any c o n t r o l mechanism which i s designed to a d j u s t demand. PARKING POLICY AS AN INCREMENTAL CONTROL MECHANISM I t has been demonstrated t h a t p a r k i n g f a c t o r s are i n f l u e n t i a l i n the mode c h o i c e d e c i s i o n . P a r k i n g p o l i c i e s may t h e r e f o r e have s u b s t a n t i a l e f f e c t s on a d j u s t i n g the mode s p l i t . The b e h a v i o r a l model of mode s p l i t shows t h a t r e s i -d e n t i a l d i s t r i b u t i o n time, CBD d i s t r i b u t i o n time and p a r k i n g r a t e s have important i n f l u e n c e s on mode c h o i c e . These are a l l 2 3 4 . f a c t o r s which c o u l d be i n c l u d e d i n a m u n i c i p a l p a r k i n g p o l i c y , p a r t i c u l a r l y a p o l i c y which i n c l u d e s r e s i d e n t i a l d i s t r i b u t i o n i n c o n j u n c t i o n with a r a p i d t r a n s i t l i n e h a u l system. P a r k i n g and R e s i d e n t i a l D i s t r i b u t i o n R e s i d e n t i a l d i s t r i b u t i o n i s a c e n t r a l determinant i n mode c h o i c e . Few s t u d i e s have been done on the m i c r o - a s p e c t s of t h i s problem, t h a t i s , aspects such as w a l k i n g d i s t a n c e to the bus s t o p , frequency of buses, d e t e r r a n t s to comfort and convenience i n making the walk p o r t i o n of the t r i p w a i t times, s h e l t e r s e t c . * Furthermore, i t may be t h a t automobile d r i v e r s have never c o n s i d e r e d these f a c t o r s . L a n s i n g and Hendricks * S e v e r a l demonstration p r o j e c t s have examined some of these: The Skokie S w i f t demonstration p r o j e c t p r o v i d e d a h i g h speed, non-stop r a p i d t r a n s i t l i n e t o a suburban community of Chicago and i n c l u d e d 522 p a r k i n g spaces a t the t e r m i n a l and f e e d e r bus s e r v i c e s . Some 18 p e r c e n t d i v e r s i o n of automobile d r i v e r s to the system was r e p o r t e d . (See Ref. 8). Grand R i v e r Bus Route Study i n D e t r o i t showed over 12 p e r c e n t i n c r e a s e i n average d a i l y patronage w i t h headways decreased from 3 1/2 - 2 minutes a t peak p e r i o d s . However, Only about 1/2 of t h i s i n c r e a s e was new bus r i d e r s . A demonstration p r o j e c t i n Boston on Bus and R a i l S e r v i c e and F a r e s t u d i e s concluded t h a t frequency of s e r v i c e was "a more important f a c t o r than lower f a r e s i n i n c r e a s i n g passenger volumes." (See Ref. 9, 10) . An 18 month study of a commuter park and r i d e t e r m i n a l on the P e n n s y l v a n i a R a i l r o a d i n which a 300 c a r f r e e p a r k i n g l o t was e s t a b l i s h e d 1 1/2 m i l e s from downtown Brunswick N.J. showed an i n c r e a s e as much as 123 p e r c e n t f o r the average week-day patronage. (See Ref. 11). In l a t e 1968 the M e t r o p o l i t a n Toronto P l a n n i n g Board's survey of the e f f e c t s of two p a r k i n g l o t s on the B l o o r - D a n f o r t h Subway l i n e on commuters showed t h a t 54.0 p e r c e n t and 4 2.8 per-c e n t r e s p e c t i v e l y of those p a r k i n g on the two l o t s had p r e v i o u s l y d r i v e n a l l the way b e f o r e the l o t s were opened. Park and r i d e passengers accounted f o r 10.5 p e r c e n t and 5.6 p e r c e n t of a l l passengers e n t e r i n g the two t e r m i n a l s . (Besides t h i s 23.1 and 42.1 p e r c e n t of a l l patrons were v i a bus and r i d e . ) (See Ref.12). show f o r example t h a t c a r d r i v e r s do not c o n s i d e r a bus b e i n g 7 a v a i l a b l e i f i t i s more than 10 minutes away. The f i n d i n g s here show t h a t a c r i t i c a l f a c t o r i n p a r k i n g and mode c h o i c e i s the e x i s t e n c e of a c o n v e n i e n t p a r k i n g and t r a n s f e r arrangement a t the r e s i d e n t i a l end of the commuter t r i p . R e s i d e n t i a l t r a v e l time ( e x c l u d i n g w a i t i n g times) has a h i g h l o a d i n g on the d i s c r i m i n a t o r between t r a n s i t r i d e r s and auto d r i v e r s . I t i s a l s o shown to have a major i n f l u e n c e on the encouragement of a s h i f t . In t h i s case the t r a v e l time f a c t o r i s t h a t between the p a r k i n g area and l o a d i n g p o i n t of the l i n e h a u l system. The c o n c l u s i o n i s t h a t to be e f f e c t i v e not o n l y must p a r k i n g be an i n t e g r a t e d p a r t of the t e r m i n a l but a l s o must seem so to the u s e r . P a r k i n g and C i t y Centre P l a n n i n g Congestion of motor v e h i c l e s i n the c e n t r e of the c i t y has long been a concern of p l a n n e r s . Some method appears to be needed to reduce c o n g e s t i o n , e i t h e r by r e s t r i c t i n g e n t r y of the people who d r i v e c a r s or by encouraging them to use t r a n s i t , on the assumption the l a t t e r w i l l have l e s s d e l e t e r i o u s e f f e c t s than the motor c a r . T h i s study has proposed an a l t e r -n a t i v e t o congestion: p a r k i n g p o l i c y as an i n c r e m e n t a l means to h e l p accomplish the end of s h i f t i n g more people to t r a n s i t . I t has been shown t h a t p a r k i n g charges would be e f f e c t i v e i n c a u s i n g some persons to s h i f t mode. I t was hoped t h a t p o l i c i e s r e l a t e d to removing worker p a r k i n g supply from the CBD to p e r i -p h e r a l areas would induce more t r a n s i t r i d e r s . However, the a n a l y s i s of b e h a v i o r showed t h i s g e n e r a l l y not to be a f a c t o r i n mode c h o i c e , and t h e r e f o r e on the b a s i s of the evidence i t must be concluded t h a t such a p o l i c y would not d e t e r many from d r i v i n g downtown to work. However, f u r t h e r r e s e a r c h on t h i s i s needed, s p e c i f i c a l l y to attempt t o i n c l u d e a CBD w a l k i n g f a c t o r i n the s h i f t p r o p e n s i t y a n a l y s i s . I n s u f f i c i e n t a n a l y s i s to date has been g i v e n to the concept of "metering" road t r a f f i c . B e e s l e y ' s and Roth's work stand out i n attempting to develop the concept of c o n g e s t i o n road p r i c i n g and the implementation of a means to c o l l e c t the revenues from such a concept. Both authors produce arguments a g a i n s t CBD p a r k i n g p o l i c y as a metering mechanism. Arguments a g a i n s t p a r k i n g p o l i c y as a c o n t r o l mechanism t o meter t r a f f i c and to a d j u s t mode s p l i t are f i r s t , t h a t c h a r g i n g those who park i n the CBD i n c r e a s e d r a t e s i n e f f e c t s u b s i d i z e s through t r a f f i c because t h e i r d i s u t i l i t y i s l e s s due to the decreased numbers of cars downtown; and sec o n d l y , t h a t there i s i n s u f -t f i c i e n t p u b l i c ownership of p a r k i n g f a c i l i t i e s t o have any e f f e c t on c o m p e t i t i v e r a t e s . The f i r s t d i f f i c u l t y may be a l l e v i a t e d i f p a r k i n g supply and l o c a t i o n are t i e d to the c a p a c i t y of the s t r e e t system s e r v i n g the downtown. I t has been shown t h a t i t i s p o s s i b l e to a d j u s t the use of s t r e e t s by p a r k i n g methods.* A p l a n n i n g o b j e c t i v e f o r c e n t r e c i t y *The author has c a r r i e d out s i m u l a t i o n s t u d i e s of t r a f f i c e n t e r i n g downtown Toronto f o r the purpose of e s t i m a t i n g the e f f e c t on s t r e e t flows of a d j u s t i n g the l o c a t i o n of p a r k i n g s u p p l y . T o t a l volumes e n t e r i n g the core, as w e l l as volumes on i n d i v i d u a l s t r e e t s c o u l d be changed by v a r y i n g the c o n f i g u r a -t i o n s of p a r k i n g supply.13 2 3 7 . p l a n n i n g , with the concept of t r a n s p o r t a t i o n c o r r i d o r s , i s to impose an upper l i m i t on the t o t a l amount of s t r e e t capa-c i t y and t h e r e f o r e p a r k i n g supply, to serve t h i s c a p a c i t y by c o r r i d o r s , and when the c a p a c i t y of the c o r r i d o r i s i n danger of b e i n g exceeded to encourage by p u b l i c p o l i c y the t r a n s f e r of a c t i v i t y generated to an improved t r a n s i t system. S i n c e CBD a c t i v i t y appears to a l s o have an upper l i m i t as the metro-p o l i t a n area grows, an e f f e c t i v e decrease i n c o n g e s t i o n would o c c u r . P a r k i n g P o l i c y C r i t e r i a These f i n d i n g s i n d i c a t e the need f o r p a r k i n g p o l i c i e s to be designed around s e v e r a l b a s i c c r i t e r i a . F i r s t , i t i s necessary to view p a r k i n g as an i n t e g r a l p a r t of the t r a n s p o r -t a t i o n system. As roads and s t r e e t s are p u b l i c r e s o u r c e s i t i s l o g i c a l t h a t the p r o t e c t i o n of investment i n t h e s e . f a c i l i t i e s i s r e l a t e d to the t e r m i n a l c a p a c i t y . T h e r e f o r e a s t r o n g argu-ment e x i s t s to i n c l u d e p a r k i n g c a p a c i t y as p a r t of t h i s system. By m u n i c i p a l c o n t r o l of p a r k i n g supply, the demand f o r and use of the p u b l i c road r e s o u r c e can be c o n t r o l l e d . While a simple requirement, the i n s t i t u t i o n a l framework i n most c i t i e s m i t i g a t e a g a i n s t p u b l i c c o n t r o l by viewing p a r k i n g o p e r a t i o n s as a use of l a n d to be c o n t r o l l e d by market f o r c e s i n the t r a d i t i o n a l manner. The a t t i t u d e i s g e n e r a l l y h e l d t h a t p a r k i n g p o l i c y i s d i r e c t e d to p r o v i d i n g a s e r v i c e to the p u b l i c . The p a r k i n g 2 3 8 . problem of the CBD i s i n v a r i a b l y seen i n terms of p a r k i n g "needs" f o r the continued v i t a l i t y of downtown or o t h e r such s e r v i c e o b j e c t i v e s . Only when t h i s s e r v i c e i s not b e i n g p r o v i d e d e f f e c t i v e l y by p r i v a t e e n t e r p r i s e , i s i t h e l d by the c u r r e n t p h i l o s o p h y t h a t "municipal agencies concerned w i t h the w e l f a r e of downtown may be j u s t i f i e d i n assuming the r o l e of p a r k i n g 14 developer." S u c c e s s f u l mode s p l i t p l a n n i n g by a p a r k i n g mechanism i s p r e d i c a t e d on p a r k i n g o p e r a t i o n s b e i n g i n s t i t u -t i o n a l l y i n t e g r a t e d w i t h s t r e e t s and t r a n s i t . Secondly, i f s t r e e t c a p a c i t y , p a r k i n g supply and t r a n s i t flows are i n balance the concept of p u b l i c c o n t r o l of p a r k i n g can i n c l u d e i t s e f f e c t on t r a n s i t whether i t i s p u b l i c l y owned or not. However, any adjustment of the balance between auto use and t r a n s i t use must i n c l u d e i n c e n t i v e s as w e l l as d i s i n c e n t i v e s . P a r k i n g r e s t r i c t i o n s by p r i c e or supply c o n t r o l s must a l s o be accompanied by t r a n s i t improvements i f the o v e r a l l p u b l i c b e n e f i t i s to be maximized. I t would be d e s i r a b l e t h a t t r a n s i t was t h e r e f o r e a l s o s u b j e c t to p u b l i c ownership or con-t r o l . To achieve an o p t i m i z a t i o n of t r a n s p o r t a t i o n s e r v i c e ( c o n s i d e r i n g only the journey to work), a p u b l i c l y owned t r a n s i t system w i t h ownership of r e s i d e n t i a l t e r m i n a l s i n c l u d i n g p a r k i n g r a t e s and supply combined w i t h p u b l i c c o n t r o l over commuter p a r k i n g a t the d i s t r i b u t i o n end of the t r i p appears n e c e s s a r y . Thus, the t r a n s i t a u t h o r i t y w i t h p a r k i n g fees and l i n e h a u l q u a l i t y d i r e c t e d to the p r o v i s i o n of i n c e n t i v e s , and m u n i c i p a l 2 3 9 . p a r k i n g p o l i c y which would support a g i v e n mode s p l i t , c o u l d be used as instruments of p u b l i c p o l i c y . The t h i r d c r i t e r i o n of p a r k i n g p o l i c y i s t h a t i t p r o v i d e f o r i n c r e m e n t a l p o l i c y adjustments. The major advan-tage of u s i n g p a r k i n g p o l i c y as a c o n t r o l mechanism i s i t s i n h e r e n t i n c r e m e n t a l investment n a t u r e . A change of a few spaces, or a minor adjustment i n r a t e s t r u c t u r e can be imple-mented q u i c k l y and i t s r e s u l t s s t u d i e d . In t h i s manner p u b l i c o b j e c t i v e s can be reached i n i n c r e m e n t a l steps w i t h l a r g e l y n o n - c a p i t a l investment d e c i s i o n s . P a r k i n g p o l i c i e s s h o u l d e x p l o i t the i n c r e m e n t a l nature of t h i s c o n t r o l mechanism and through g r a d u a l , and i n c r e m e n t a l , changes a c h i e v e p u b l i c ends. O p e r a t i o n a l adjustment such as r a t e i n c r e a s e s , a p a r k i n g tax, r a t e s t r u c t u r e c o n t r o l s ; as w e l l as investments i n f a c i l i t i e s are more o r l e s s r e v e r s i b l e . P a r k i n g l o t opera-t i o n i s l a r g e l y c o n s i d e r e d commercially as a h o l d i n g use of l a n d , i n which a p a r k i n g l o t becomes a temporary revenue pro-ducer a w a i t i n g change over to a more p r o f i t a b l e use. T h e r e f o r e , the temporary nature of p a r k i n g o p e r a t i o n s can be used to advantage by t e s t i n g o p e r a t i o n a l changes w i t h o u t l a r g e c a p i t a l commitments. (The commitments here, even f o r say a m u n i c i p a l l y owned p a r k i n g garage, are n o t h i n g l i k e those of s t r e e t widenings i n b u i l t up areas, downtown freeway c o n s t r u c t i o n , o r r a p i d t r a n s i t ) . 2 4 0 . P a r k i n g p o l i c y o p t i o n s however f a c e important bar-r i e r s to s u c c e s s f u l implementation of a mode s h i f t . The study has shown t h a t a g r e a t number of c a r d r i v e r s park f r e e . There-f o r e r a t e s t r u c t u r e changes w i l l not a f f e c t these people. A l s o most of these- employees have s u f f i c i e n t l e v e r a g e to demand o n - s i t e p a r k i n g thus a l s o e f f e c t i v e l y making themselves immune from l o c a t i o n p o l i c i e s . There are a l s o people who use t h e i r c a r s d u r i n g the day and would not, i n any case, be ab l e t o s h i f t . These two groups r e p r e s e n t the i r r e d u c i b l e minimum car p o p u l a t i o n i n the CBD. THE PROPENSITY MODEL A primary s i g n i f i c a n c e of the study was the development of a p r o p e n s i t y model to study mode s h i f t . The model appears to be a f e a s i b l e t o o l f o r a n a l y s i s and t e s t s of a c o n t r o l mechanism. The model t e s t s show f o r example t h a t a modest decrease i n t r a v e l time would e f f e c t a s i g n i f i c a n t s h i f t t o a park and r i d e type multimodal system. In p r a c t i c e such a r e d u c t i o n i n t r a v e l time would be d i f f i c u l t because of the multimodal concept i n c o r p o r a t i n g v e h i c l e t r a n s f e r s , and the n e c e s s i t y f o r almost time-continuous t r a v e l i n c l u d i n g v ery f r e q u e n t s e r v i c e . However, n e i t h e r the time c o n s t r a i n t s nor f r e q u e n c i e s are u n r e a l i s t i c and wit h d e s i g n and p l a n n i n g f e a t u r e s mentioned elsewhere have p o s s i b i l i t i e s . The t e s t s show t h a t d r i v e r s w i l l t o l e r a t e some wal k i n g i n the system. I t appears t h a t e x i s t i n g w a l k i n g d i s -tances i n the CBD of Vancouver are r e l a t i v e l y g r e a t and may 2 4 1 . account f o r the r e l a t i v e i n s e n s i t i v i t y to v/alking. There i s no doubt t h a t both r e s i d e n t i a l times and CBD w a l k i n g times are c o n s i d e r e d j o i n t l y by the t r i p maker, and must be con-s i d e r e d i n one p o l i c y s e t . Unexpectedly p a r k i n g c o s t when combined w i t h t r a n s i t f a r e d i d not assume as much importance i n encouraging a s h i f t as a n t i c i p a t e d . I t may be t h a t the t r i p maker views these combined c o s t s as a s i n g l e journey c o s t . P a r k i n g c o s t by i t s e l f however d i d appear to be a s i g n i f i c a n t f a c t o r i n the s h i f t model. The model s u b s t a n t i a t e s the h y p o t h e s i s t h a t s o c i o -economic s t r u c t u r e has a s i g n i f i c a n t i n f l u e n c e on the v a l u e p l a c e d on d i f f e r e n t dimensions of the system and s e n s i t i v e -ness to mode s h i f t s . As expected the more a f f l u e n t and e s t a b -l i s h e d groups would r e s i s t a s h i f t , but unexpectedly p r o f e s -s i o n a l o c c u p a t i o n s would be s h i f t - s e n s i t i v e . T h i s conforms to the f i n d i n g s elsewhere i n the study and i n d i c a t e s p o t e n t i a l s h i f t patrons among t h i s group. NEW TECHNOLOGICAL FACTORS IN MODE SPLIT PLANNING Of major importance i s the t r a v e l time from r e s i d e n c e to the bus s t o p . A l l t e s t s showed t h i s . T h i s f i n d i n g emphasi-zes the importance of the multimodal concept as opposed to a p o l i c y of s i n g l e t e c h n o l o g i c a l improvements to the l i n e h a u l system. No l i n e h a u l system, r e g a r d l e s s of the s e r v i c e p r o v i d e d on the l i n e h a u l w i l l be s u c c e s s f u l i n a t t r a c t i n g patronage u n l e s s the r e s i d e n t i a l t r a v e l time p e r c e i v e d i s d e s i r a b l e by the u s e r . C u r r e n t experiments are b e i n g conduc-ted which may h o l d promise i n p r o v i n g a v i a b l e d i a l - a - b u s system f o r t h i s s e r v i c e . Feeder bus ro u t e s can serve a park and r i d e system with l i n e h a u l p r o v i d e d by express buses or by r a p i d r a i l t r a n s i t . One a p p l i c a t i o n i s , the bus-freeway r i n which buses . and ca r s are metered onto a freeway i n the 15 mix which p r o v i d e s r a p i d bus t r a n s i t d u r i n g peak perxods. T h i s system has the p o t e n t i a l of a s i n g l e mode from home to work wi t h buses p r o v i d i n g both l o c a l and r a p i d t r a n s i t s e r v i c e . The bus-freeway i s b e i n g experimented w i t h i n th r e e l o c a t i o n s , and although the e f f e c t on mode s p l i t i s s t i l l unknown the i n f e r e n c e i s t h a t i f the r e s i d e n t i a l d i s t r i b u t i o n system can be s u c c e s s f u l l y implemented mode s p l i t adjustments w i l l o c c u r . F i n d i n g s show a l s o t h a t b e t t e r bus f r e q u e n c i e s are c r i t i c a l t o mode s h i f t and any fe e d e r bus system would need to p r o v i d e b e t t e r than e x i s t i n g average f r e q u e n c i e s . T h i s would pr o b a b l y imply s m a l l e r buses and i n t u r n would p r o b a b l y neces-s i t a t e s u b s i d i z a t i o n , s i n c e the c o s t of l a b o r i s a major o p e r a t i o n a l c o s t of a t r a n s i t system.* The r e d u c t i o n of the pay l o a d w i t h s m a l l e r buses i s a s e r i o u s b o t t l e n e c k to system r a t i o n a l i z a t i o n . E q u a l l y , t h i s f a c t o r a l s o i s predominant *For example d r i v e r c o s t s of the Toronto T r a n s i t Commission amounts t o between 60-65 p e r c e n t o f the systems o p e r a t i o n s c o s t . 243 . i n t h e d o w n t o w n d i s t r i b u t i o n s y s t e m , w h i c h a l t h o u g h n o t s h o w n i n t h i s a n a l y s i s t o b e a n i m p o r t a n t d e t e r m i n a n t o f s h i f t , d o e s h a v e s o m e i m p a c t . T h e M i n i b u s o f W a s h i n g t o n D.C. i s c o n s i d e r e d s u c c e s s f u l f o r s h o p p i n g t r i p s a n d a s i m i l a r s y s t e m m a y b e e f f e c -t i v e f o r w o r k t r i p s . H o w e v e r , t h e f i n d i n g s h e r e i n d i c a t e n o s u b s t a n t i a l e f f e c t o n m o d e s p l i t f o r w o r k t r i p s . T h i s r e s e a r c h h a s r e d u c e d t h e m o d e s t o a b s t r a c t i o n s o f t i m e , c o s t , c o n v e n i e n c e f a c t o r s a n d i n t h i s m a n n e r h a s a t t e m p t e d t o r e l a t e d e m a n d t o t h e a t t r i b u t e s o f p o s s i b l e m o d e s r a t h e r t h a n t o t h e m o d e s t h e m s e l v e s . T h i s h a s b e e n e f f e c t i v e i n s h o w i n g t h e m o d a l c h a r a c t e r i s t i c s w h i c h n e e d t o b e i n c o r -p o r a t e d i n t o n e w t e c h n o l o g i c a l c h a n g e s . R e c e n t l y m a n y s u g g e s -t i o n s h a v e b e c o m e e x t a n t a n d s o m e o f t h e s e h o l d p r o m i s e i n t h e l i g h t o f t h e f i n d i n g s o f t h i s r e s e a r c h . T h e d i a l - a - b u s f e e d e r s y s t e m , t h e d u a l m o d e s y s t e m i n w h i c h a p r i v a t e v e h i c l e i s t r a n s f e r r e d t o a n a u t o m a t e d l i n e h a u l s y s t e m a r e p o s s i b i l i t i e s . H o w e v e r , t h i s r e s e a r c h h a s l e d t o t h e c o n c l u s i o n t h a t a c o n v e n -t i o n a l e x p r e s s b u s c o m b i n e d w i t h a p a r k a n d r i d e f e e d e r s y s t e m c o u l d b e m a d e s u c c e s s f u l w i t h o u t r a d i c a l i n n o v a t i o n s . H o w e v e r i t s s u c c e s s i s d e p e n d e n t u p o n t h e c o n v e n i e n t t r a n s f e r f r o m a u t o m o b i l e t o b u s a n d t h e r e d u c t i o n o f t e r m i n a l w a i t i n g t i m e s . T h e f i n d i n g s o f t h i s s t u d y i n d i c a t e l i t t l e s u b s t a n -t i a l s h i f t f r o m t h e c a r m o d e u n l e s s t r a n s f e r a n d w a i t i n g t i m e s b y a n a l t e r n a t i v e m o d e b e r e d u c e d o r e l i m i n a t e d . ( A n a l t e r -n a t i v e p h i l o s o p h y m a y b e t o d e c r e a s e l i n e h a u l t i m e s e n o u g h to "swamp" the importance of w a i t i n g and t r a n s f e r t i m e s ) . The only p r a c t i c a l method of p r o v i d i n g a n e a r l y continuous journey downtown i s the combination of automobile p a r k i n g and a f a s t l i n e h a u l system. T h i s combination of modes has the most p r o -mise i n c u t t i n g down on r e s i d e n t i a l t r i p times, i n - t r i p t r a n s -f e r s and w a i t i n g times. A commuter can c o n t r o l h i s t r a n s f e r time by h i s de p a r t u r e time from home to a r r i v e a t the t e r m i n a l a t the l a s t p o s s i b l e moment. By i n t e g r a t e d d e s i g n of p a r k i n g f a c i l i t i e s and bo a r d i n g p l a t f o r m s the d i s t a n c e o f the t r a n s f e r can c o n c e i v a b l y be ve r y s h o r t . The r e d u c t i o n of time and d i s -tance, as w e l l as very f r e q u e n t l i n e h a u l s e r v i c e , would appear to s a t i s f y s u b s t a n t i a l numbers of commuters. LIMITATIONS OF STUDY AND FURTHER RESEARCH The' data r e q u i r e d s u b s t a n t i a l r e d u c t i o n and r e f o r -matting t o put them i n a form t o be a n a l y s e d by m u l t i v a r i a t e methods. Consequently i t i s d i f f i c u l t t o assess the i n t e r -p r e t a t i o n s of the a n a l y s i s i n view of the assumptions i n h e r e n t i n the t e s t s , and the p o p u l a t i o n v a r i a n c e s . I n t e r v a l s c a l e d v a r i a b l e s would be d e s i r a b l e throughout. Because o f the c a t e -g o r i c a l nature of the responses t o the q u e s t i o n n a i r e the r e s u l t i n g s c a l e was a h i g h l e v e l o r d i n a l one, and based on the r e s u l t s produced appear to be reasonably r e p r e s e n t a t i v e of p o p u l a t i o n s t a t i s t i c s . New t e s t s of t h i s n a t u r e , however, sho u l d be conducted t o r e f i n e the s c a l i n g procedures a t the survey l e v e l . T h i s i s a problem i n v i r t u a l l y a l l mode c h o i c e r e s e a r c h . 2 4 5 . A problem i n the t e s t s of s u b j e c t i v e responses i s v a l i d i t y of the response as a base f o r p u b l i c d e c i s i o n making. Some would argue t h a t measures of b e h a v i o r o n l y a r e v a l i d means of i d e n t i f y i n g mode c h o i c e and p r e f e r e n c e . There have been no s t u d i e s i n t r a n s p o r t a t i o n p l a n n i n g on the r e l a t i o n s h i p between responses on h y p o t h e t i c a l b e h a v i o r and subsequent a c t i o n . Mean-w h i l e such t e s t s as have been c a r r i e d o u t i n t h i s study a r e n e c e s s a r y u n t i l b e t t e r d a t a c o l l e c t i o n methods can be used t o i n c o r p o r a t e checks on t h i s type of q u e s t i o n . An argument i s a l s o b e i n g c a r r i e d out i n mode c h o i c e r e s e a r c h as r e g a r d u s i n g p e r c e i v e d as opposed to o b j e c t i v e measures of v a r i a b l e s . Most r e c e n t s t u d i e s have used s u b j e c t i v e measures. Quarmby t e s t e d s u b j e c t i v e and o b j e c t i v e responses and found good c o r r e l a t i o n w i t h r e g a r d to w a l k i n g time r e p o r t e d and a c t u a l d i s t a n c e measured on a map. A study i s c u r r e n t l y b e i n g c a r r i e d out a t N o r t h -16 western U n i v e r s i t y on the p e r c e i v e d - o b j e c t i v e q u e s t i o n . P r e -l i m i n a r y r e s u l t s imply t h a t p e r c e i v e d measures may f a i r l y r e p -l i c a t e o b j e c t i v e measures f o r h a b i t u a l t r a v e l p a t t e r n s , such as the work t r i p . The p r e s e n t study i s based on p e r c e i v e d v a r i a b l e s with e v i d e n c e t h a t i n some cases the measures v a r y s i g n i f i c a n t l y from o b j e c t i v e ones. The a u t h o r i s c o n v i n c e d t h a t t h i s type of response i s a v a l i d one i n mode c h o i c e r e s e a r c h as a method to s i m u l a t e the v a r i a b l e s o b j e c t i v e l y . A g r e a t amount of a n a l y s i s of t h i s q u e s t i o n i s s t i l l n e c e s s a r y . The p l a n n i n g mechanism used to e x p l o r e mode s p l i t demand adjustment was a d i s c r i m i n a t i o n - c l a s s i f i c a t i o n model which can be used to s i m u l a t e i n t e r m o d a l demand w i t h changes i n performance l e v e l s of the system. The mechanism c o n s i s t s ' of two sub-models: one an e m p i r i c a l g e n e r a l i z a t i o n of i n t e r -modal demand based on system b e h a v i o r , and a t h e o r e t i c a l u t i l i t y model of the i n f e r r e d p r o p e n s i t y to s h i f t mode based on s u b j e c -t i v e p r e f e r e n c e s f o r changes i n the system. The d i s c r i m i n a t i o n - c l a s s i f i c a t i o n approach has been used s e v e r a l times to p r e d i c t mode c h o i c e s i n c e Warner's i n i t i a l e f f o r t i n 1962. T h i s type o f model has two major advan-tages over the m u l t i p l e l i n e a r r e g r e s s i o n type. F i r s t l y , i t all o w s a d i s a g g r e g a t i o n of the data i n t o i n d i v i d u a l b e h a v i o r u n i t s , thereby a v o i d i n g problems of e c o l o g i c a l f a l l a c y and s p u r i o u s n e s s . L i n e a r r e g r e s s i o n models depend on a continuous d i s t r i b u t i o n f o r i t s dependent v a r i a b l e . Thus, i n v e s t i g a t o r s use a s e r i e s of t r a f f i c zones as the b a s i c b e h a v i o r a l u n i t to meet t h i s assumption. The i n d i v i d u a l mode c h o i c e problem i s however d i s c o n t i n u o u s . A change i n , say, t r a v e l time may make an i n d i v i d u a l s w i t c h from c a r to t r a n s i t but i t cannot make him l e s s of a c a r user than a t p r e s e n t . The d i s c r i m i n a n t c r i t e r i o n p o s t u l a t e s a dichotomous dependent v a r i a b l e (mode choice) and the assignment of an i n d i v i d u a l i s to one o r the ot h e r s i d e of a d i s c r i m i n a n t boundary depending upon the charac-t e r i s t i c s o f the mode s e l e c t e d . I t i s t h e r e f o r e a p p r o p r i a t e to the problem as to whether an i n d i v i d u a l i n a c e r t a i n popu-l a t i o n takes e i t h e r t r a n s i t or auto. That i s , the dependent v a r i a b l e i s b i n a r y v a l u e d i n s t e a d of c o n t i n u o u s . 2 4 7 . The second advantage of the d i s c r i m i n a t i o n - c l a s s i -f i c a t i o n approach i s t h a t the d i s c r i m i n a n t f u n c t i o n s are analogous to the a g g r e g a t i o n of u t i l i t y f u n c t i o n s f o r each i n d i v i d u a l and t h e r e f o r e can be r e l a t e d to a t h e o r e t i c a l frame-work. The d i s c r i m i n a n t f u n c t i o n i s a l i n e a r boundary s e p a r a t i n g groups as an envelope e n c l o s i n g groups on the c r i t e r i o n t h a t the v a r i a n c e o f o b s e r v a t i o n s w i t h i n the group i s s t a t i s t i c a l l y l e s s than v a r i a n c e between groups. The d i s c r i m i n a n t s c o r e , as the q u a n t i t a t i v e v a l u e of the d i s c r i m i n a n t f u n c t i o n i s a r e l a t i v e q u a n t i t a t i v e measure of a l i n e a r i z e d v a l u e f u n c t i o n . The c o e f f i c i e n t s of the f u n c t i o n are the r e l a t i v e c o n t r i b u t i o n s of each v a r i a b l e under study, and i s thereby a r e l a t i v e measure of the u t i l i t y o f t h a t f a c t o r i n the mode c h o i c e d e c i s i o n . The combination of b e i n g a b l e to p r e d i c t group membership, thereby a l l o w i n g a s t r a t i f i c a t i o n o f the mode c h o i c e d e c i s i o n i n t o as many s t r a t a as p o s s i b l e ; and i t s r e l a t i o n s h i p t o ' u t i l i t y theory makes the d i s c r i m i n a n t - c l a s s i f i c a t i o n approach u s e f u l f o r the study o f mode c h o i c e . I t s v a l u e however l i e s i n c l a s -s i f i c a t i o n , not i n p r e d i c t i o n . The models developed and t e s t e d here produce the antecedents to a more complete a n a l y s i s u s i n g a wider range o f v a r i a b l e s , and t e s t e d on f u r t h e r d a t a . F u r t h e r r e s e a r c h i s needed to c a r r y out s i m u l a t i o n t e s t s u s i n g a wider range of both socioeconomic and t r a n s p o r t a t i o n system d a t a . Some authors have a l s o experimented w i t h o t h e r p r o b a b i l i t y models such as p r o b i t a n a l y s i s and l o g i t a n a l y s i s . L i s c o , f o r one, cla i m s 2 4 8 . b e t t e r p r e d i c t i v e a b i l i t y f o r these models. F u r t h e r s t u d i e s are needed on both the r e l a t i v e advantages of d i s c r i m i n a n t f u n c t i o n and o t h e r models to f u l l y a n a l y s e t h i s . T h i s study was an a n a l y s i s of a g i v e n data base c o l l e c t e d f o r another purpose. The a n a l y s i s p r o v i d e s some i n s i g h t i n t o the problem of determinants f o r a p a r k i n g model to study mode s h i f t , and the i n c i d e n c e of p a r k i n g p o l i c y on mode c h o i c e . P a r t of the r e s u l t s of the study was to p o i n t out those v a r i a b l e s , and means of measurement, which s h o u l d be s t u d i e d i n more depth. P r i n c i p a l l y among these i s 'the concept of t r a v e l comfort which has not been a n a l y s e d i n any study. Comfort f a c t o r s appear to be a prime c o n s i d e r a t i o n i n t r a v e l consumption. T h e r e f o r e f u r t h e r r e s e a r c h e f f o r t s are needed to d e f i n e the dimensions o f comfort and to attempt means of measurement and q u a n t i f i c a t i o n . REFERENCES CHAPTER I A l e x i s , N. Sommers, "Towards a Theory of T r a v e l l e r Mode Choice," High Speed-Ground T r a n s p o r t a t i o n J o u r n a l , January 1970', V o l . IV, No. 1, p. 3. 2 I b i d . , p.1. 3 M a r t i n J . F e r t a l and A l i F. S e v i n , " E s t i m a t i n g T r a n s i t Usage," i n Urban Mass T r a n s i t P l a n n i n g , I n s t i t u t e of T r a n s p o r t a t i o n and T r a f f i c E n g i n e e r i n g (Be r k e l e y : U n i v e r s i t y of C a l i f o r n i a , 1967), pp.55-77. 4 W i l b u r A. Steger and T.R. Lakshmanan, "Plan E v a l u a t i o n Methodology: Some Aspects of D e c i s i o n Require-ments and A n a l y t i c a l Response," i n Urban Development Models, Highway Research Board, S p e c i a l Report 97 (Washington: Highway Research Board, 1968), pp.33 -76 . 5 I b i d . , p.38. Wilb u r R. Thompson, A P r e f a c e to Urban Economics ( B a l t i m o r e : Resources f o r the Fut u r e Inc., Johns Hopkins P r e s s , 1965). Edwin N. Thomas and Joseph L. Sc h o f e r , " S t r a t e g i e s f o r the E v a l u a t i o n of A l t e r n a t i v e T r a n s p o r t a t i o n P l a n s , " N a t i o n a l C o o p e r a t i v e Highway Research Program Report 96 (Washington: Highway Research Board, 1970). I b i d . , p.22. 9 I b i d . , p.22. David Braybrooke and C h a r l e s E. Lindblom, A S t r a t e g y  f o r D e c i s i o n : P o l i c y E v a l u a t i o n as a S o c i a l Process (New York: The Free Press of Glencoe, 1963) . M.E. B e e s l e y , "Congestion P r i c i n g , " Second I n t e r -n a t i o n a l Symposium on Theory and P r a c t i c e i n T r a n s p o r t Economics ( B r u s s e l s : 1967), pp.391-441. 250, 1 2 G a b r i e l Roth, Paying f o r Roads: The Economics  of T r a f f i c C ongestion (Harmondsworth: Penguin Books, 1967) 1 3 B e e s l e y , op. c i t . , p.392. 251. REFERENCES CHAPTER I I Robert B. M i t c h e l l and Chester Rapkin, Urban  T r a f f i c : A F u n c t i o n of Land Use (New York: Columbia U n i v e r -s i t y P r e s s , 1954) . 2 D e t r o i t M e t r o p o l i t a n Area T r a f f i c Study, P a r t s I and 2 ( D e t r o i t , 1955-56). 3 Chicago Area T r a n s p o r t a t i o n Study, V o l . 2 (Chicago: J u l y 1960) . 4 P i t t s b u r g h Area T r a n s p o r t a t i o n Study, V o l s . 1 and 2 ( P i t t s b u r g h : 1961). 5 Frank B. Curran and Joseph D. Stegmaier, T r a v e l  P a t t e r n s i n 50 C i t i e s , Highway Research Board B u l l e t i n 203 (Washington; Highway Research Board, 1958). g Warren T. Adams, F a c t o r s I n f l u e n c i n g T r a n s i t and  Automobile Use i n Urban Areas, Highway Research Board B u l l e t i n 230 (Washington: Highway Research Board, 1959) . 7 Chicago Area T r a n s p o r t a t i o n Study, op. c i t . g Edward T a a f f e e t a l , The P e r i p h e r a l Journey to Work, (Evanston: Northwestern U n i v e r s i t y P r e s s , 1963). 9 John Meyer, John F. Kain and M a r t i n Wohl, The Urban  T r a n s p o r t a t i o n Problem (Cambridge: Harvard U n i v e r s i t y P r e s s , 1965) . "^Edmond L. Kanwit and Alma F. E c k a r t t , T r a n s p o r t a t i o n  I m p l i c a t i o n s of Employment Trends i n C e n t r a l C i t i e s and Suburbs, a Paper p r e s e n t e d a t the 46th Annual Meeting of the Highway Research Board (Washington: 1967). "'""'"Central Area T r a n s p o r t a t i o n Study (Toronto: M e t r o p o l i t a n Toronto' P l a n n i n g Board, 1967) . 12 ' John B. L a n s i n g , and Gary H e n d r i c k s , Automobile Ownership and R e s i d e n t i a l D e n s i t y (Ann Arbor: U n i v e r s i t y o f Mic h i g a n , June 1967) . 252. 13 S t a n l e y Leon Warner, S t o c h a s t i c Choice of Mode i n Urban T r a v e l : A Study i n B i n a r y Choice (Evanston: Northwestern U n i v e r s i t y P r e s s , 1962). 14 F r e d e r i c k C. Bock, F a c t o r s I n f l u e n c i n g Modal T r i p  Assignment, N a t i o n a l C o o p e r a t i v e Highway Research Program Report 57 (Washington: Highway Research Board, 1968). 15' C h a r l e s A. Lave, "A B e h a v i o r a l Approach to Modal S p l i t F o r e c a s t i n g , " T r a n s p o r t a t i o n Research, V o l . 3, No. 4, 1969. 16 Puget Sound Re g i o n a l T r a n s p o r t a t i o n Study, Summary Report ( S e a t t l e : 1967). 17 The M e t r o p o l i t a n Toronto T r a n s p o r t a t i o n P l a n , (Toronto: M e t r o p o l i t a n Toronto P l a n n i n g Board, 1964) . 18 1962) 1959) Washington Area T r a n s p o r t a t i o n Study (Washington: 19 Penn-Jersey T r a n s p o r t a t i o n Study ( P h i l a d e l p h i a : 20 Warner, op. c i t . 21 D.A. Quarmby, "Choice of T r a v e l Mode f o r the Journey t o Work," J o u r n a l o f T r a n s p o r t Economics and P o l i c y , September, 1967. 22 L e s t e r A. Hoel e t a l , L a t e n t Demand f o r Urban  T r a n s p o r t a t i o n ( P i t t s b u r g h : C a r n e g i e - M e l l o n U n i v e r s i t y , 1968) . 23 Warner, op. c i t . 24 T a a f f e , op. c i t . 25 D . Bock, op. c i t . 2 6 Nancy J . L e a t h e r s , " R e s i d e n t i a l L o c a t i o n and Mode of T r a n s p o r t a t i o n to Work: A Model of Cho i c e , " T r a n s p o r t a t i o n Research, V o l . 1, 1967. F.R. W i l s o n , Journey to Work - Modal S p l i t (London: Maclaren and Sons L t d . , 1967). 2 8 Wilson, op. c i t . 29 John F. K a i n , A C o n t r i b u t i o n t o the Urban Transpor-t a t i o n Debate: An Econometric Model of Urban R e s i d e n t i a l and T r a v e l B ehavior (Santa Monica: RAND P u b l i c a t i o n , P-2667, 1962) . "^Walter O i and P a u l S h u l d i n e r , Urban T r a v e l Demands, (Evanston: Northwestern U n i v e r s i t y P r e s s , 1962) . 31 Leo G. Reeder, " S o c i a l D i f f e r e n t i a l s i n Mode o f T r a v e l , Time and Cost i n the Journey to Work," American  S o c i o l o g i c a l Review, V o l . 21, No. 1, February 19 56. 32 John F. K a i n , "The Commuting and R e s i d e n t i a l D e c i s i o n s of C e n t r a l Business D i s t r i c t Workers," T r a n s p o r t a t i o n  Economics (New York: Columbia U n i v e r s i t y P r e s s , 1965). 33 E i r e T r a n s p o r t a t i o n Study ( E i r e : 1966). 34 The Puget Sound R e g i o n a l T r a n s p o r t a t i o n Study, o p . c i t 35 M e t r o p o l i t a n Toronto P l a n n i n g Board, T r a n s p o r t a t i o n  Research Program, Report No. 1, u n p u b l i s h e d (Toronto: 1962). 3 6 Donald M. H i l l , and Hans G. von Cube, Development  of a Model f o r F o r e c a s t i n g T r a v e l Mode Choice i n Urban Areas, Highway Research Record 3 8 (Washington: HRB, 1963). 37 . . D.M. H i l l and Norman Dodd, T r a v e l Mode S p l i t i n Assignment Programs, Highway Research Board B u l l e t i n 347 (Washington: HRB, 1962) . 3 8 Washington Area T r a n s p o r t a t i o n Study, op. c i t . 39 . Penn-Jersey T r a n s p o r t a t i o n Study, op. c i t . ^ T w i n C i t i e s Area T r a n s p o r t a t i o n Study (Minneapolis, S t . P a u l : 1960). ^ N i a g a r a F r o n t i e r T r a n s p o r t a t i o n Study ( B u f f a l o : 1962) 254. 4 2Quarmby, op. c i t . 43 R i c h a r d H. P r a t t , "A U t i l i t a r i a n Theory of T r a v e l Mode Choice," u n p u b l i s h e d paper g i v e n t o HRB Meeting (Washington: January 1970) . 44 A l l a n N. Nash and S t a n l e y J . H i l l e , P u b l i c  A t t i t u d e s Toward T r a n s p o r t Modes: A Summary of Two P i l o t S t u d i e s , Highway Research Record 233 (Washington: HRB, 19 68) . 45 Bock, op. c i t . 46 R u s s e l l L. A c k o f f , I n d i v i d u a l P r e f e r e n c e s f o r  Va r i o u s Means of T r a n s p o r t a t i o n , ( P h i l a d e l p h i a : U n i v e r s i t y of P e n n s y l v a n i a , 1965). 47 A r t h u r B. S o s s l a u and A r t h u r J . Balek, E v a l u a t i o n  of a New Modal S p l i t Procedure, Highway Research Record 88 (Washington: HRN, 1965). 48 . Quarmby, op. c i t . 49 Park N' Ride R a i l S e r v i c e : New Brunswick, Newark, New York (New York: T r i - S t a t e T r a n s p o r t a t i o n Commission, 1967). 50 Subway T e r m i n a l P a r k i n g Survey, Memorandum o f M e t r o p o l i t a n Toronto P l a n n i n g Board, (Toronto: March 25, 1969). 51 P e t e r R. Stopher, A P r o b a b i l i t y Model o f T r a v e l  Mode Choice f o r the Work Journey, Highway Research Record 283, (Washington: HRB, 1969). 52 G e r a l d M. McCarthy, M u l t i p l e - R e g r e s s i o n A n a l y s i s of Household T r i p G e n e r a t i o n - A C r i t i q u e , Highway Research Board Record 297 (Washington: HRB, 1969). 53 Bruce G. Hutchinson, "Recent Advances i n Urban T r a n s p o r t Systems P l a n n i n g , " A Paper p r e s e n t e d a t the VI World Highway Conference (Montreal: 1970). 54 I r a S. Lowry, "A Sh o r t Course i n Model Design," J o u r n a l of the American I n s t i t u t e of P l a n n e r s , V o l . XXXI, No. 2, May, 1965. 55 C h a r l e s R i v e r and A s s o c i a t e s , A Model of Urban  Passenger T r a v e l Demand i n the San F r a n c i s c o M e t r o p o l i t a n Area (Cambridge, Mass.: 1967). ^ M c C a r t h y , op. c i t . 57 K e l v i n J . L a n c a s t e r , "A New Approach to Consumer Theory," J o u r n a l of P o l i t i c a l Economy, V o l . 74, 1966. 5 R R i c h a r d E. Quandt and W i l l i a m J . Baumol, "The Demand f o r A b s t r a c t T r a n s p o r t Modes: Theory and Measurement," J o u r n a l of R e g i o n a l S c i e n c e , V o l . 6, No. 2, 1966. 59 R i c h a r d E. Quandt, " E s t i m a t i o n o f Model S p l i t s , " T r a n s p o r t a t i o n Research, V o l . 2, March, 1968. 6 0 Kan Hau Young, "An A b s t r a c t Mode Approach to the Demand f o r T r a v e l , " T r a n s p o r t a t i o n Research, V o l . 3, 19 69. 61 Warner, op. c i t . 6 2 A c k o f f , op. c i t . 6^Quarmby, op. c i t . 64 Quandt, op. c i t . 65 P r a t t , op. c i t . 6 6 Robert G. M c G i l l i v r a y , "Demand and Choice Models of Modal S p l i t , " J o u r n a l of T r a n s p o r t Economics and P o l i c y , May, 1970. ^ A c k o f f , op. c i t . 6 8 Nash and H i l l e , op. c i t . A l e x i s N. Sommers, "Towards a Theory of T r a v e l l e r Mode Choice," High Speed Ground T r a n s p o r t a t i o n J o u r n a l , V o l . IV, No. 1, January, 1970. Thomas F. Golob, "The Survey of User Choice of A l t e r n a t i v e T r a n s p o r t a t i o n Modes," High Speed Ground Trans-p o r t a t i o n J o u r n a l , V o l . IV, No. 1, January, 1970. 256. 71 John L a n s i n g and Gary H e n d r i c k s , How People P e r c e i v e  the Cost of the Journey to Work, unpublished (Ann Arbor: U n i v e r s i t y of M ichigan, 1967). 72 Lowdon Wingo J r . , T r a n s p o r t a t i o n and Urban Land, Resources f o r the F u t u r e (Washington: 1961). 73 Thomas B. Dean, W i l l i a m L. Mertz, Neal A. I r w i n , A p p l i c a t i o n of a Modal S p l i t Model to T r a v e l E s t i m a t e s f o r the  Washington Area, Highway Research Board 3 8 (Washington: HRB, 1963) . 74 J e f f r e y M. Zapan, Mode Choice: I m p l i c a t i o n s f o r  P l a n n i n g , Highway Research Record 251 (Washington: HRB, 1968). Zupan, op. c i t . 7 6 P h i l i p J . Rulon, David V. Tiedeman e t a l , M u l t i v a r i a t e S t a t i s t i c s f o r P e r s o n n e l C l a s s i f i c a t i o n (New York: John Wiley & Sons, 1967). 77 M c G i l l i v r a y , op. c i t . 7 8 A l f r e d M a r s h a l l , P r i n c i p l e s of Economics (London: Ma c M i l l a n , 1966) . 79 Quandt and Baumol, op. c i t . 8 0 C e n t r a l Area T r a n s p o r t a t i o n Study, op. c i t . 81 Meyer, K a i n and Wohl, op. c i t . 8 2 C e n t r a l Area T r a n s p o r t a t i o n Study, op. c i t . 8 3 E. T r o x e l , Economics of T r a n s p o r t (New York: R i n e h a r t and Co., 1955). 257. REFERENCES CHAPTER I I I N.D. Lea and A s s o c i a t e s , Measures to Improve Bus  T r a n s i t and T r a f f i c Flows Across the F i r s t Narrows B r i d g e , ( V i c t o r i a : B.C. Highways Department, 1967). 2 I b i d . 3 I b i d . 4 John B. La n s i n g and Gary H e n d r i c k s , Automobile  Ownership and R e s i d e n t i a l D e n s i t y (Ann Arbor: U n i v e r s i t y of M i c h i g a n , 1967). ^Bernard R. B l i s h e n , "A Socio-Economic Index f o r Occupations i n Canada," Canadian S o c i e t y (Toronto: M a c M i l l a n , 1967) . g L a n s i n g and He n d r i c k s , op. c i t . 7 S e l e c t e d Data from the Vancouver T r a n s p o r t a t i o n Study, (Vancouver: P l a n n i n g Department, 1967). 8 A l a n M. Voorhees, F a c t o r s and Trends i n T r i p Lengths, N.C.H.R.P. (Washington: Highway Research Board, 1968). 9 F r e d e r i c k C. Bock, F a c t o r s I n f l u e n c i n g Modal T r i p  Assignment, N.C.H.R.P. (Washington: Highway Research Board, 1968) . "^Voorhees, op. c i t . "'""'"Jeffrey M. Zupan, "Mode Cho i c e : I m p l i c a t i o n s f o r P l a n n i n g , " Highway Research Record 251 (Washington: HRB, 1968). • 12 Report on a Comprehensive P u b l i c T r a n s p o r t a t i o n P l a n For the S e a t t l e M e t r o p o l i t a n Area ( S e a t t l e : 1967). 13 . The M e t r o p o l i t a n Toronto T r a n s p o r t a t i o n P l a n (Toronto: M e t r o p o l i t a n Toronto P l a n n i n g Board, 1964). 258. 14 The Minibus i n Washington, D.C., D i s t r i c t of Columbia Mass T r a n s p o r t a t i o n Demonstration P r o j e c t (Washington: 1965). 15 D.A. Quarmby, "Choice of T r a v e l Mode f o r the Journey to Work," J o u r n a l of T r a n s p o r t Economics and P o l i c y , September, 1967. I b i d . 17 R i c h a r d A. P r a t t , "A U t i l i t a r i a n Theory of T r a v e l Mode Choice," u n p u b l i s h e d paper g i v e n to HRB Meeting, (Washington: January, 1970). 18 La n s i n g and He n d r i c k s , op. c i t . 19 Robert W. Smith, Summary of R e s u l t s of a P i l o t  Study i n F i v e Canadian C i t i e s on A t t i t u d e s and H a b i t s i n Route and Mode S e l e c t i o n f o r the Journey to Work, (Ottawa: CCURR, 1967) . N.D. Lea, op. c i t . 259. REFERENCES CHAPTER I V •^Bernard R. B l i s h e n , "A Socio-Economic Index f o r Occupations i n Canada," Canadian S o c i e t y (Toronto: MacMillan, 1967) . 2 "Quinn McNemar, P s y c h o l o g i c a l S t a t i s t i c s , 4th ed. (New York: John Wiley, 1969). 3 S t a n l e y Leon Warner, S t o c h a s t i c C h o i c e of Mode i n  B i n a r y Choice (Evanston: Northwestern U n i v e r s i t y P r e s s , 1962). 4 K e i t h Hope, Methods of M u l t i v a r i a t e A n a l y s i s (London: U n i v e r s i t y of London P r e s s , 1968), p.121. ^T.W. Anderson, An I n t r o d u c t i o n to M u l t i v a r i a t e S t a t i s t i c a l A n a l y s i s (New York: Wiley, 1958). W^.W. Cooley, and P a u l R. Lohnes, M u l t i v a r i a t e  Procedures f o r the B e h a v i o r a l S c i e n c e s (New York: Wiley, 1962) , ^Anderson, op. c i t . g R.A. F i s h e r , "The Use of M u l t i p l e Measurements i n Taxonomic Problems," Annals of Eugenics, V o l . 7, 1936. 9 C R . Rao, Advanced S t a t i s t i c a l Methods i n B i o m e t r i c  Research (New York: Wiley, 1952). "^M.G. K e n d a l l , A Course i n M u l t i v a r i a t e A n a l y s i s , (London: C h a r l e s G r i f f i n , 1957) . ''"'''Anderson, op. c i t • 12 P h i l i p J . Rulon e t al_, M u l t i v a r i a t e S t a t i s t i c s f o r  P e r s o n n e l C l a s s i f i c a t i o n (New York: Wiley, 1967). 1 3 „ Hope, op. c i t . 14 Cooley and Lohnes, op. c i t . , p. 62. 260. Rao, op. ext., p.246. " ^ L e s l i e K i n g , S t a t i s t i c a l A n a l y s i s i n Geography (New J e r s e y : P r e n t i c e - H a l l , 1969). 17 S e v e r a l a p p l i c a t i o n s i n s o c i o l o g y and geography have emphasized the h y p o t h e s i s t e s t i n g r o l e of d i s c r i m i n a n t a n a l y s i s . See f o r example: Solomon,Rettig, " M u l t i p l e D i s c r i m i n a n t A n a l y s i s : An I l l u s t r a t i o n , " American S o c i o l o g i c a l  Review, V o l . 29, No. 3, June 19 64, pp.398-402; L y l e U. Jones and R. D a r r e l l Bock, " M u l t i p l e D i s c r i m i n a n t A n a l y s i s A p p l i e d to 'Ways to L i v e ' Ratings from S i x C u l t u r a l Groups," Sociometry V o l . 23, 1960, pp.162-175; L e s l i e J . King, " D i s c r i m i n a t o r y A n a l y s i s of Urban Growth P a t t e r n s i n O n t a r i o and Quebec, 1951-1961," Annals of AAG, V o l . 57, pp.566-578; Ni r m a l a d e v i C h e r u k u p a l l e , Demographic P a t t e r n s of U r b a n i z a t i o n i n I n d i a : A D i s c r i m i n a n t A n a l y s i s , u n p u b l i s h e d Ph.D. D i s s e r t a t i o n , Harvard U n i v e r s i t y , May 1967. F r e d e r i c k C. Bock's study of F a c t o r s I n f l u e n c i n g L o c a l T r i p Assignment, N.C.H.R.P. Report 57, Highway Research Board, 1968, f i t s i n t o t h i s c a t e g o r y as w e l l . 18„ Rao, op. c i t . 19 J e f f r e y Zupan, "Mode Choice: I m p l i c a t i o n s f o r P l a n n i n g , " Highway Research Record 251 (Washington: HRB, 1968). Robert G. M c G i l l i v r a y , "Demand and Choice Models of Modal S p l i t , J o u r n a l of T r a n s p o r t Economics and P o l i c y , May 1970, pp.192-206. REFERENCES CHAPTER V L e t t e r from W.S. Homburger, I n s t i t u t e of Trans-p o r t a t i o n and T r a f f i c E n g i n e e r i n g , U n i v e r s i t y o f C a l i f o r n i a , B e r k e l e y , 1 9 7 1 . 2 Kenneth Arrow, S o c i a l Choice and I n d i v i d u a l Values (London: Wiley, 1 9 5 7 ) . 3 D a n i e l Katz and E z r a S t o t l a n d , P r e l i m i n a r y Statement to a Theory of A t t i t u d e s , - i n Psychology, V o l . 3 (New York: McGraw H i l l , 1 9 5 9 ) . 4 Katz and S t o t l a n d , op. c i t . . 5W.W. Lambert and W.E. Lambert, S o c i a l Psychology (Englewood C l i f f s : P r e n t i c e H a l l , 1 9 6 4 ) . 262. REFERENCES CHAPTER VI ''"Unpublished S t a t i s t i c s of the Toronto T r a n s i t Commission (Toronto: TTC, 1968). 2 -C e n t r a l Area T r a n s p o r t a t i o n Study (Toronto: M e t r o p o l i t a n Toronto P l a n n i n g Board, 1967) . 3 R i c h a r d M. Z e t t e l , "On S t u d y i n g the Impact of Rapid T r a n s i t i n the San F r a n c i s c o Bay Area," Impact of the Bay Area  Rapid T r a n s i t System on the San F r a n c i s c o M e t r o p o l i t a n Region, (Washington: Highway Research Board S p e c i a l Report 191, 1970), 4 The Memphis T r a n s i t A u t h o r i t y , Mass T r a n s p o r t a t i o n  S t u d i e s i n Memphis, Suburban R i d e r s h i p Demonstration P r o j e c t , 1965. 5 Robert G. M c G i l l i v r a y , "Demand and Choice Models of Modal S p l i t , " J o u r n a l of T r a n s p o r t Economics and P o l i c y , May 1970, pp.192-206. g Thomas E. L i s c o , Mass T r a n s p o r t a t i o n : C i n d e r e l l a i n Our C i t i e s , A R e p r i n t from The P u b l i c I n t e r e s t , No. 18, Winter, 1970. 7 John L a n s i n g and Gary Hendricks, Automobile Owner-s h i p and R e s i d e n t i a l D e n s i t y , Survey Research Center (Ann Arbor:. U n i v e r s i t y of Michigan, 1967). g Thomas Buck, Skokie S w i f t , The Commuters F r i e n d , (Chicago: Chicago T r a n s i t A u t h o r i t y , May 1968). 9 C i t y of D e t r o i t , Grand R i v e r Avenue T r a n s i t Survey, D e t r o i t , M i c h i g a n : HHFA Demonstration Grant Program, January 1963 . ^ M a s s T r a n s p o r t a t i o n Commission, Commonwealth of Massachusetts, Mass T r a n s p o r t a t i o n i n Massachusetts, J u l y 1964 ^ " * T r i - S t a t e T r a n s p o r t a t i o n Commission, Park N' Ride  R a i l S e r v i c e : New Brunswick, Newark, New York (New York: May 1967) . 263 . 12 M e t r o p o l i t a n Toronto P l a n n i n g Board, Report on  Rapid T r a n s i t P r i o r i t i e s i n M e t r o p o l i t a n Toronto, (Toronto: u n p u b l i s h e d , 1968). 13 C e n t r a l Area T r a n s p o r t a t i o n Study, op. c i t . 14 W i l b u r Smith and A s s o c i a t e s , T r a n s p o r t a t i o n and  P a r k i n g f o r Tomorrow's C i t i e s (New Haven: 1966) . " ^ V e r g i l G. S t o v e r and John C. Glennon, "A System f o r Bus Rapid T r a n s i t on Urban Freeways," T r a f f i c Q u a r t e r l y , (Saugatuck: Eno Foundation, October 1969). 16 P e t e r L. Watson, Some Problems A s s o c i a t e d w i t h  the Time and Cost Data Used i n T r a v e l Choice M o d e l l i n g  and the V a l u a t i o n of Time, un p u b l i s h e d , 1971. SELECTED BIBLIOGRAPHY A. BOOKS Anderson, T.W. An I n t r o d u c t i o n to M u l t i v a r i a t e S t a t i s t i c a l  A n a l y s i s . New York: John Wiley and Sons, 1958. Arrow, Kenneth. S o c i a l Choice and I n d i v i d u a l V a l u e s . London: John Wiley & Sons, 19 51. Baumol, W i l l i a m J . Economic Theory and O p e r a t i o n s A n a l y s i s . Englewood C l i f f s : P r e n t i c e - H a l l , 1961. B e r r y , B.J.L. Essays on Commodity Flows and the S p a t i a l S t r u c t u r e  of the I n d i a n Economy. Chicago: U n i v e r s i t y of Chicago Research Paper, No. I l l , 1966. Blumenfeld, Hans. The Modern M e t r o p o l i s . e d i t e d by P a u l D. S p r e i r e g e n , M o n t r e a l : Harvest House, 1967. Braybrooke, David, and C h a r l e s E. Lindblom. A S t r a t e g y of  D e c i s i o n . New York: Free P r e s s , 1963. B r e i t , W i l l i a m , and H a r o l d Hochman. Readings i n Microeconomics. New York: H o l t , R i n e h a r t and Winston, 1968. Buchanan, C D . T r a f f i c i n Towns. London: M i n i s t r y of T r a n s p o r t , H.M.S.O., 1963. C l a r k s o n , G e o f f r e y F.E. The Theory of Consumer Demand: A  C r i t i c a l A p p r a i s a l . Englewood C l i f f s : P r e n t i c e - H a l l , 1963. Cooley, W i l l i a m W., and P a u l R. Lohnes. M u l t i v a r i a t e Procedures  f o r the Behavior S c i e n c e s . New York: John Wiley and Sons, 1962. Goode, W i l l i a m J . , and P a u l K. H a t t . Methods i n S o c i a l Research. New York: McGraw-Hill, 1952. Hoel, L e s t e r A. e t a l . L a t e n t Demand f o r Urban T r a n s p o r t a t i o n . P i t t s b u r g h : C a r n e g i e - M e l l o n I n s t i t u t e , 1968. Homburger, Wolfgang, (ed.). Urban Mass T r a n s i t P l a n n i n g . B e r k e l e y : The I n s t i t u t e of T r a n s p o r t a t i o n and T r a f f i c E n g i n e e r i n g , U n i v e r s i t y of C a l i f o r n i a , 1967. 265. Hope, K e i t h . Methods of M u l t i v a r i a t e A n a l y s i s . London: U n i v e r s i t y of London P r e s s , 1968. K e n d a l l , M.G. A Course i n M u l t i v a r i a t e A n a l y s i s . London: C h a r l e s G r i f f i n and Co., 1957. King, L e s l i e . S t a t i s t i c a l A n a l y s i s i n Geography. New J e r s e y : P r e n t i c e - H a l l , 1969. Lambert, W i l l i a m W. and Wallace E. Lambert. S o c i a l Psychology. Englewood C l i f f s : . P r e n t i c e - H a l l , 1964 . L a n s i n g , John B., and Gary H e n d r i c k s . Automobile Ownership and  R e s i d e n t i a l D e n s i t y . Ann Arbor: U n i v e r s i t y of M ichigan, 1967 . L a p i n , Howard S. S t r u c t u r i n g the J o u r n a l to Work. P h i l a d e l p h i a : U n i v e r s i t y of P e n n s y l v a n i a P r e s s , 1964. McNemar, Quinn. P s y c h o l o g i c a l S t a t i s t i c s , 4th ed. New York: John Wiley and Sons, 1969. Marshal, A l f r e d . P r i n c i p l e s of Economics. 8th e d i t i o n . London: Macmillan, 19 66. Meyer, J.R., J.F. K a i n and M. Wohl. The Urban T r a n s p o r t a t i o n  Problem. Cambridge: Harvard U n i v e r s i t y P r e s s , 1965. M i t c h e l l , Robert B., and Chester Rapkin. Urban T r a f f i c : A  F u n c t i o n of Land Use. New York: Columbia U n i v e r s i t y P r e s s , 1954. O i , W alter, and Paul S h u l d e i r e r . An A n a l y s i s of Urban T r a v e l Demands. Evanston: Northwestern U n i v e r s i t y P r e s s , 1962. Rao, C R . Advanced S t a t i s t i c a l Methods i n B i o m e t r i c Research. New York: John Wiley and Sons, 1952. Rao, C R . L i n e a r S t a t i s t i c a l I n f e r e n c e and I t s A p p l i c a t i o n s . New York: John Wiley and Sons, 1965. Roth, G a b r i e l . Paying f o r Roads: The Economics 'of T r a f f i c  C o n gestion . Harmondsworth: Penguin, 1967. Rulon, P h i l l i p J.,, David V. Tiedeman, Maurice M. Tatsuoka, and C h a r l e s R. Langmuir. M u l t i v a r i a t e S t a t i s t i c s f o r P e r s o n n e l  C l a s s i f i c a t i o n . New York: John Wiley and Sons, 1967. Schneider, Lewis M. M a r k e t i n g Urban Mass T r a n s i t . Cambridge: Harvard U n i v e r s i t y P r e s s , 1965. 266. Smith, W i l b u r , and A s s o c i a t e s . T r a n s p o r t a t i o n and P a r k i n g f o r  Tomorrow's C i t i e s . New Haven: Automobile Manufacturers A s s o c i a t i o n , 1966. Smith, W i l b u r , and A s s o c i a t e s . P a r k i n g i n the C i t y C enter. New Haven: Automobile Manufacturers A s s o c i a t i o n , 1965. T a a f f e , Edward J . , B a r r y J . Garner, and Maurice H. Yeates. The P e r i p h e r a l Journey to Work: A G e o g r a p h i c a l C o n s i d e r a -t i o n . Evanston: The T r a n s p o r t a t i o n Center, Northwestern U n i v e r s i t y P r e s s , 1963. Thompson, Wilbur R. A P r e f a c e to Urban Economics. B a l t i m o r e : Johns Hopkins P r e s s , 1968. Warner, S t a n l e y Leon. S t o c h a s t i c Choice o f Mode i n Urban T r a v e l : A Study i n B i n a r y C h o i c e . Evanston: The T r a n s p o r t a t i o n C e n ter, Northwestern U n i v e r s i t y P r e s s , 1962. W i l s o n , F.R. Journey to Work - Modal S p l i t . London: Maclaren and Sons, 196 7. Wingo, Lowden J r . T r a n s p o r t a t i o n and Urban Land. Wadington: Resources f o r the Future Inc., 1961. B. PERIODICALS Adams, Warren T. " F a c t o r s I n f l u e n c i n g T r a n s i t and Automobile Use i n Urban Areas," Highway Research Board B u l l e t i n 230. Washington: Highway Research Board, 1959, pp. 101-111. Alexander, Lawrence A. "The Downtown P a r k i n g System," T r a f f i c  Q u a r t e r l y . V o l . XXIII, No. 2, A p r i l , 1969, pp. 197-206. B e e s l e y , M.E. "The Value of Time Spent i n T r a v e l l i n g : Some New Evidence," Economica, May, 1965, pp. 174-185. B l i s h e n , Bernard. "The C o n s t r u c t i o n and Use of an O c c u p a t i o n a l C l a s s S c a l e , " Canadian J o u r n a l of Economics and P o l i t i c a l  S c i e n c e , V o l . 24, November, 1958, pp. 519-531. Culp, C h a r l e s A. " M u n i c i p a l P r o v i s i o n of P a r k i n g F a c i l i t i e s , " Highway Research Board Record 168. Washington: Highway Research Board, 1967. pp. 12-52. Curran, Frank B. and Joseph Stegmaier. " T r a v e l P a t t e r n s i n 50 C i t i e s , " Highway Research Board B u l l e t i n 203. Washington: Highway Research Board, 19 58, pp. 99-130. Deen, Thomas B., W i l l i a m L. Mertz, and Neal A. I r w i n . " A p p l i c a t i o n of a Modal S p l i t Model to T r a v e l E s t i m a t e s for:; the Washington Area," Highway Research Board Record 38. Washington: Highway Research Board, 1963. G a u t h i e r , Howard L. " T r a n s p o r t a t i o n and the Growth of the Sao Paulo Economy," J o u r n a l o f Regional S c i e n c e , V o l . 8, No. 1, 1968, pp. 77-94. Go l o b , Thomas_ F. "The Survey of User Choice of A l t e r n a t i v e T r a n s p o r t a t i o n Modes," High Speed Ground T r a n s p o r t a t i o n  J o u r n a l , V o l . IV, No. 1, Jan. 1970, pp. 103-116. Gould, P.R. "On the G e o g r a p h i c a l I n t e r p r e t a t i o n of E i g e n v a l u e s , " T r a n s a c t i o n s No. 42, I n s t i t u t e of B r i t i s h Geographers. London: George P h i l i p and Son, 1967, (December 1967), pp. 53-86. H i l l , Donald M., and Hans G. von Cube. "Development of a Model f o r F o r e c a s t i n g T r a v e l Mode Choice i n Urban Areas," Highway Research Board Record 38, Washington, Highway Research Board, 1963, pp. 78-96. H i l l , Donald M., and Norman Dodd. " T r a v e l Mode S p l i t i n Assignment Programs," Highway Research Board Record 3 47. Washington: Highway Research Board, 1962, pp. 290-301. H i l l e , S t a n l e y J . , and Theodore K. M a r t i n . "Consumer P r e f e r e n c e i n T r a n s p o r t a t i o n , " Highway Research Board Record 197. Washington: Highway Research Board, 1967, pp. 36-41. Hyman, G.M., and A. G. W i l s o n . "The E f f e c t s of Changes i n T r a v e l Costs on T r i p D i s t r i b u t i o n and Modal S p l i t , " High Speed Ground T r a n s p o r t a t i o n J o u r n a l , V o l . I l l , No. 1, January, 1969. Jones, L y l e V., and R. D a r r e l l Bock. " M u l t i p l e D i s c r i m i n a n t A n a l y s i s A p p l i e d t o "Ways to L i v e " Ratings from S i x C u l t u r a l Groups," Sociometry, V o l . 23, 1960, pp. 162-176. Lambe, Thomas A. "The Choice of P a r k i n g L o c a t i o n by Workers i n the C e n t r a l Business D i s t r i c t , " T r a f f i c Q u a r t e r l y , V o l . XXIII, No. 3, J u l y , 1969, pp. 397-411. L a n c a s t e r , K e l v i n J . "A New approach to Consumer Theory," J o u r n a l of P o l i t i c a l Economy, V o l . 47, 1966, pp. 133-157. Lave, C h a r l e s A. "A B e h a v i o r a l Approach to Modal S p l i t F o r e -c a s t i n g , " T r a n s p o r t a t i o n Research, V o l . 3, No. 4, 1969, pp. 463-480. 268 . L e a t h e r s , Nancy J . " R e s i d e n t i a l L o c a t i o n and Mode of Trans-p o r t a t i o n to Work: A Model of C h o i c e , " T r a n s p o r t a t i o n  Research, V o l . 1, 1967, pp. 129-155. L i s c o , Thomas E. "Mass T r a n s p o r t a t i o n : C i n d e r e l l a i n our C i t i e s , " The P u b l i c I n t e r e s t , No. 18, Winter, 1970. N a t i o n a l A f f a i r s Inc., 1970, pp. 52-74. Lowry, I r a S. "A S h o r t Course i n Model Design," J o u r n a l of  the American I n s t i t u t e of P l a n n e r s , V o l . XXXI, No. 2, May, 1965. Katz, D. and E. S t o t l a n d . "A P r e l i m i n a r y Statement to a Theory o f A t t i t u d e S t r u c t u r e and Change," Psychology: A Study  of a S c i e n c e . V o l . 3, New York: McGraw-Hill, 1959. McCarthy, G e r a l d M. " M u l t i p l e - R e g r e s s i o n A n a l y s i s of Household T r i p G e n e r a t i o n — A C r i t i q u e , " Highway Research Board Record  297. Washington: Highway Research Board, 1969, pp. 37-42. M c G i l l i v r a y , Robert G. "Demand and Choice Models of Modal S p l i t , " J o u r n a l of T r a n s p o r t Economics and P o l i c y , May, 1970, pp. 192-207. Moses, Leon W., and H a r o l d F. W i l l i a m s o n , J r . "Value of Time, Choice of Mode, and the Subsidy Issue i n Urban T r a n s p o r t a -ti o n , " J o u r n a l of P o l i t i c a l Economy, V o l . LXXI, No. 3, June, 1963, pp. 247-264. P a t r a s s i , Angelo. " B a l a n c i n g Road and T r a n s i t Systems," T r a f f i c  Q u a r t e r l y , V o l . XXIII, No. 3, J u l y , 1969, pp. 441-460. Quandt, R i c h a r d E. " E s t i m a t i o n of Modal S p l i t s , " T r a n s p o r t a t i o n  Research, V o l . 2, No. 2, 1968, pp. 41-50. Quandt, R i c h a r d E., and W i l l i a m J . Baumol. "The Demand f o r A b s t r a c t T r a n s p o r t Modes: Theory and Measurement," J o u r n a l o f R e g i o n a l S c i e n c e , V o l . 6, No. 2, 1966, pp. 13-26. Quarmby, D.A. " R e l a t i n g P u b l i c T r a n s p o r t t o Urban P l a n n i n g , " J o u r n a l o f the I n s t i t u t e o f T r a n s p o r t . V o l . 30, No. 12, Sept. 1964. Quarmby, D.A. "Choice of T r a v e l Mode f o r the Journey to Work," J o u r n a l of T r a n s p o r t Economics and P o l i c y , Sept., 1967, pp. 273-314. Reeder, Leo G. " S o c i a l D i f f e r e n t i a l s i n Mode of T r a v e l , Time and Cost i n the Journey to Work," American S o c i o l o g i c a l  Review, V o l . 21, No. 1, Feb., 1956, pp. 56-63. 269. R e t t i g , Solomon. " M u l t i p l e D i s c r i m i n a n t A n a l y s i s : An I l l u s -t r a t i o n , " American S o c i o l o g i c a l Review, V o l . 29, No. 3, June 1964, pp. 398-402. Sommers, A l e x i s N. "Towards a Theory of T r a v e l e r Mode Choice," High Speed Ground T r a n s p o r t a t i o n J o u r n a l , V o l . IV, No. 1, Jan. 1970, pp. 1-8. S o s s l a u , A r t h u r B., and A r t h u r J . Balek. " E v a l u a t i o n of a New Modal S p l i t Procedure," Highway Research Board Record 88. Washington: Highway Research Board, 1965. Stopher, P e t e r R. "A P r o b a b i l i t y Model of T r a v e l Mode Choice f o r the Work Journey," Highway Research Board Record 283. Highway Research Board, 1969, pp. 57-65. S t o v e r , V e r g i l G., and John C. Glennon. "A System f o r Bus Rapid T r a n s i t on Urban Freeways," T r a f f i c Q u a r t e r l y , October 1969, Sargatuck: Eno Foundation, 1969, pp. 465-484. T r u e t t , Bruce, and A r t h u r J . Balek. "On the Need f o r a D e f i n i t i o n of Demand f o r T r a n s p o r t a t i o n , " High Speed Ground T r a n s p o r t a -t i o n J o u r n a l , V o l . I I , No. 3, September, 1968. Wachs, M a r t i n . " R e l a t i o n s h i p Between D r i v e r s ' A t t i t u d e s Toward A l t e r n a t i v e Routes and D r i v e r and Route C h a r a c t e r i s t i c s , " Highway Research Board Record 197. Washington: Highway Research Board, 1967. pp. 70-87. Weiner, Edward. "Modal S p l i t R e v i s i t e d , " T r a f f i c Q u a r t e r l y , January 1969, pp. 5-28. Sangatuck: Eno Foundation, 1969. Young, Kan Hua. "An A b s t r a c t Mode Approach t o the Demand f o r T r a v e l , " T r a n s p o r t a t i o n Research, V o l . 3, No. 4, 19 69, pp. 443-461. Zupan, J e f f r e y M. "Mode Choice: I m p l i c a t i o n s f o r P l a n n i n g , " Highway Research Board Record 251. Washington: Highway Research Board, 1968. C. SPECIAL REPORTS Beesley, M.E. "Congestion P r i c i n g , " Theory and P r a c t i c e i n  T r a n s p o r t Economics. Second I n t e r n a t i o n a l Symposium, European Conference o f M i n i s t e r s of T r a n s p o r t , B r u s s e l s , 1967, pp. 391-441. Bock, F r e d e r i c k C. F a c t o r s I n f l u e n c i n g Modal T r i p Assignment. N a t i o n a l C o o p e r a t i v e Highway Research Program Report 57. Washington: Highway Research Board, 1968. 2 7 0 . C e n t r a l Area T r a n s p o r t a t i o n Study. Toronto: M e t r o p o l i t a n Toronto P l a n n i n g Board, 1 9 6 7 . F e r t a l , M a r t i n J . , Edward Weiner, A. A r t h u r J . Balek, and A l i F. S e v i n . Modal S p l i t : Documentation of Nine Methods  f o r E s t i m a t i n g T r a n s i t Usage. Washington: Bureau of P u b l i c Roads, O f f i c e of P l a n n i n g , 1 9 6 6 . Lea, N.D. and A s s o c i a t e s . T r a f f i c on the F i r s t Narrows B r i d g e -Vancouver. V i c t o r i a : B.C. Highways Department, 1 9 6 7 . Lower Manhattan P l a n . New York: The New York C i t y P l a n n i n g Commission, 1 9 6 6 . M e t r o p o l i t a n Toronto P l a n n i n g Board. Report on the M e t r o p o l i t a n  Toronto T r a n s p o r t a t i o n P l a n . Toronto: M.T.P.B., 1 9 6 4 . Park N'Ride R a i l S e r v i c e : New Brunswick, Newark, New York. New York: T r i - S t a t e T r a n s p o r t a t i o n Commission, 1 9 6 7 . Puget Sound R e g i o n a l T r a n s p o r t a t i o n Study, Summary Report. S e a t t l e : Puget Sound Governmental Conference, 1 9 6 7 . The Minibus i n Washington D.C. D i s t r i c t of Columbia Mass T r a n s p o r t a t i o n Demonstration P r o j e c t , Washington: May, 1 9 6 5 . Thomas, Edwin N. and Joseph L. Schoper. S t r a t e g i e s f o r the E v a l u a t i o n of A l t e r n a t i v e T r a n s p o r t a t i o n P l a n s . N a t i o n a l C o o p e r a t i v e Highway Research Program Report 9 6 . Washington: Highway Research Board, 1 9 7 0 . T r a n s i t Usage F o r e c a s t i n g Techniques: A Review and New D i r e c t i o n s . P i t t s b u r g h : Cousad Research Corp., 1 9 6 8 . T r a n s p o r t a t i o n Research Program Report No. 1 . Toronto: Metro-p o l i t a n Toronto P l a n n i n g Board, 1 9 6 2 . Vancouver Downtown P a r k i n g , P a r t I. C i t y E n g i n e e r i n g Department, Vancouver, 1 9 6 2 . Voorhees, A l a n M. F a c t o r s and Trends i n T r i p Lengths. N a t i o n a l C o o p e r a t i v e Highway Research Program Report 4 8 . Washington: Highway Research Board, 1 9 6 8 . Z e t t e l , R i c h a r d M. "On S t u d y i n g the Impact of Rapid T r a n s i t i n the San F r a n c i s c o Bay Area," Impact of the Bay Area  Rapid T r a n s i t System on the San F r a n c i s c o M e t r o p o l i t a n  Region, Highway Research Board S p e c i a l Report 1 9 1 . Washington: Highway Research Board, 1 9 7 0 . Report on a Comprehensive P u b l i c T r a n s p o r t a t i o n P l a n f o r the S e a t t l e M e t r o p o l i t a n A r e l u S e a t t l e : Puget Sound Govern-ment Conference, 1 9 6 7 . 2 7 1 . R i v e r , C h a r l e s and A s s o c i a t e s . A M o d e l o f U r b a n P a s s e n g e r  T r a v e l Demand i n t h e San F r a n c i s c o M e t r o p o l i t a n A r e a . C a m b r i d g e : C h a r l e s R i v e r s and A s s o c i a t e s , 1 9 6 7 . S t e g e r , W i l b u r A., and T.R. Lakshmanan. " P l a n E v a l u a t i o n M e t h o d o l o g i e s , " Highway R e s e a r c h B o a r d S p e c i a l R e p o r t 9 7 . W a s h i n g t o n : Highway R e s e a r c h B o a r d , 1 9 6 8 , pp. 3 3 - 7 2 . S t o u f f e r , S a mual. " A t t i t u d e s as R e l a t e d t o S u b s e q u e n t B e h a v i o r , " S o c i a l R e s e a r c h t o T e s t I d e a s . New Y o r k : F r e e P r e s s , G l e n c o e , 1 9 6 2 , pp. 1 9 3 - 2 2 2 . Subway T e r m i n a l P a r k i n g S u r v e y . Memorandum, M e t r o p o l i t a n T o r o n t o P l a n n i n g B o a r d , T o r o n t o : M a r c h 2 5 , 1 9 6 9 . Swan-Wooster E n g i n e e r i n g . V a n c o u v e r P u b l i c T r a n s p o r t a t i o n  P l a n n i n g f o r t h e F u t u r e . V a n c o u v e r : May, 1 9 6 8 . D. UNPUBLISHED DOCUMENTS A c k o f f , R u s s e l l L . " I n d i v i d u a l P r e f e r e n c e s f o r V a r i o u s Means o f T r a n s p o r t a t i o n , " u n p u b l i s h e d , P h i l a d e l p h i a : U n i v e r s i t y o f P e n n s y l v a n i a . B a s m a c i y a n , Herman. " D e v e l o p m e n t and A p p l i c a t i o n o f a M o d a l S p l i t M o d e l f o r t h e P u g e t Sound R e g i o n , " u n p u b l i s h e d p a p e r o f P u g e t Sound R e g i o n a l T r a n s p o r t a t i o n S t u d y , May 19 64. C h e r u k u p a l l e , N i n v a l a D e v i . " D e m o g r a p h ic P a t t e r n s o f U r b a n i -z a t i o n i n I n d i a : A D i s c r i m i n a n t A n a l y s i s , " u n p u b l i s h e d Ph.D. t h e s i s , H a r v a r d U n i v e r s i t y , C a m b r i d g e , 1967. Deen, Thomas B. "A S t u d y o f T r a n s i t F r i n g e P a r k i n g U sage," u n p u b l i s h e d f i n d i n g s o f F r i n g e P a r k i n g , N a t i o n a l C a p i t a l R e g i o n by A l a n M. V o o r h e e s and A s s o c i a t e s , p r e p a r e d f o r t h e N a t i o n a l C a p i t a l P l a n n i n g C o m m i s s i o n , W a s h i n g t o n , 1955. D i Renzo, J o h n F. and L o u i s P. R o s s i . "A D i v e r s i o n M o d e l f o r E s t i m a t i n g H i g h - S p e e d R a i l U s age," u n p u b l i s h e d p a p e r p r e s e n t e d a t t h e 5 0 t h A n n u a l M e e t i n g o f t h e Highway R e s e a r c h B o a r d , W a s h i n g t o n , J a n u a r y , 1971. E r g i i n , Gokmen, "Devel o p m e n t o f a Downtown P a r k i n g M o d e l , " u n p u b l i s h e d p a p e r p r e s e n t e d a t t h e 5 0 t h A n n u a l M e e t i n g o f t h e Highway R e s e a r c h B o a r d , W a s h i n g t o n , J a n u a r y , 1971. G o l o b , Thomas F., and R i c h a r d L. G u s t a f s o n . " E c o n o m i c A n a l y s i s o f a Demand - R e s p o n s i v e P u b l i c T r a n s p o r t a t i o n S y s t e m , " u n p u b l i s h e d p a p e r p r e s e n t e d a t t h e 5 0 t h A n n u a l M e e t i n g o f t h e Highway R e s e a r c h B o a r d , W a s h i n g t o n : J a n u a r y , 1971. 272. Gustaf-son, R i c h a r d L. , H a r r i e t N. Curd, and Thomas F. Golob. "User P r e f e r e n c e s f o r a Demand - Responsive T r a n s p o r t a t i o n System: A Case Study Report," unpublished paper p r e s e n t e d to the 50th Annual Meeting of the Highway Research Board, Washington, January, 1971. Haney, D.G. "Consistency i n T r a n s p o r t a t i o n Modal S p l i t and E v a l u a t i o n Models," u n p u b l i s h e d paper p r e s e n t e d at the 50th Annual Meeting of the Highway Research Board, Washington, January, 1971. Hartgen, David T. and George H. Tanner. " I n v e s t i g a t i o n s of the E f f e c t of T r a v e l e r A t t i t u d e s i n a Model of Mode Choice B e h a v i o r , " u n p u b l i s h e d paper p r e s e n t e d a t the 50th Annual Meeting of the Highway Research Board, Washington, January, 1971. Hoxie, P a u l , and Edvards Aldana. "Comparison of C l a s s i f i c a t i o n Techniques f o r E s t i m a t i n g the Value of Time," u n p u b l i s h e d Department of C i v i l E n g i n e e r i n g , M a s s a c h u s e t t s • I n s t i t u t e of Technology, n.d. Hutchinson, Bruce G. • "Recent Advances i n Urban T r a n s p o r t Systems P l a n n i n g , " u n p u b l i s h e d paper p r e s e n t e d a t the VI World Highway Conference, M o n t r e a l , October, 1970. Ka i n , John F. "A C o n t r i b u t i o n t o the Urban T r a n s p o r t a t i o n Debate: An Econometric Model of Urban R e s i d e n t i a l and T r a v e l B e havior," unpublished paper of the RAND Corpora-t i o n , November, 1962. Ka i n , John F. "Commuting and the R e s i d e n t i a l D e c i s i o n s o f Chicago and D e t r o i t C e n t r a l Business D i s t r i c t Workers," u n p u b l i s h e d paper of the RAND C o r p o r a t i o n , paper P-2735, A p r i l , 1963. Kauwit, Edmond L., and Alma F. E c k a r t t . " T r a n s p o r t a t i o n I m p l i -c a t i o n s o f Employment Trends i n C e n t r a l C i t i e s and Suburbs," u n p u b l i s h e d paper p r e s e n t e d a t the 46th Annual Meeting of the Highway Research Board, Washington, 1967. La n s i n g , John B., and Gary H e n d r i c k s . "How People P e r c e i v e the C o s t o f the Journey to Work," u n p u b l i s h e d paper o f the Survey Research Center, I n s t i t u t e f o r S o c i a l Research, U n i v e r s i t y of Michigan, Ann Arbor, 1967. L i s c o , Thomas E. " P r o j e c t Statement, Northwest Chicago C o r r i d o r Modal S p l i t P r o j e c t , " u n p u b l i s h e d paper. Chicago: Chicago Area T r a n s p o r t a t i o n Study, 1969. 2 7 3 . Nash, A l l a n N., and S t a n l e y J . H i l l e . " P u b l i c A t t i t u d e s Toward T r a n s p o r t Modes: A Summary of Two P i l o t S t u d i e s , " unpub-l i s h e d paper presented a t the 47th Annual Meeting of the Highway Research Board, Washington, January, 1968. Navin, F r a n c i s P., and Gordon W. S c h u l t z . A Technique to C a l i b r a t e Choice Models, u n p u b l i s h e d . Washington: A l a n M. Voorhees and A s s o c i a t e s , n.d. P r a t t , R i c h a r d H. "A U t i l i t a r i a n Theory of T r a v e l Mode Choice," u n p u b l i s h e d , n.d. Reichman, Shalom, and P e t e r R. Stopher. "Towards Disaggregate S t o c h a s t i c Models of T r a v e l Mode Choice," u n p u b l i s h e d paper p r e s e n t e d a t the 50th Annual Meeting of the Highway Research Board, Washington, January, 1971. S c h u l t z , Gordon W., and R i c h a r d H. P r a t t . " E s t i m a t i n g Multi-Mode T r a n s i t Use i n a C o r r i d o r A n a l y s i s , " u n p u b l i s h e d paper p r e s e n t e d a t the 50th Annual Meeting of the Highway Research Board, Washington, January, 1971. Seekings, M.R. "A D i r e c t Demand Model f o r Modal S p l i t , " unpub-l i s h e d Master's t h e s i s , Department of C i v i l E n g i n e e r i n g , U n i v e r s i t y of Toronto, Toronto, 1968. Shunk, Gordon A., and R i c h a r d J . Bouchard. An A p p l i c a t i o n of Ma r g i n a l U t i l i t y to T r a v e l Mode Device, u n p u b l i s h e d . Washington: A l a n M. Voorhees and A s s o c i a t e s , n.d. Smith, Robert W. " A t t i t u d e s Toward Urban T r a n s p o r t a t i o n Systems," u n p u b l i s h e d paper p r e s e n t e d a t the 50th Annual Convention of the Canadian Good Roads A s s o c i a t i o n , Edmonton, A l b e r t a , October, 1969. Smith, Robert W. "Summary of R e s u l t s of a P i l o t Study i n F i v e Canadian C i t i e s on A t t i t u d e s and Habi t s i n Route and Mode S e l e c t i o n f o r the Journey to Work," u n p u b l i s h e d . Ottawa: Canadian C o u n c i l on Urban and Re g i o n a l Research, n.d. Stopher, P e t e r R., and Thomas E. L i s c o . " M o d e l l i n g T r a v e l Demand: A Disaggregate B e h a v i o r a l Approach Issues and A p p l i c a t i o n s , " u n p u b l i s h e d paper p r e s e n t e d to the 11th Annual Meeting of the T r a n s p o r t a t i o n Research Forum, New O r l e a n s , October, 1970. Voorhees, A l a n M. "Parking F a c t s - What's the Problem?" u n p u b l i s h e d paper, A l a n M. Voorhees and A s s o c i a t e s , Washington, n.d. Voorhees, A l a n M. and A s s o c i a t e s . ."Calgary Modal S p l i t Model," u n p u b l i s h e d paper of the Calgary Area T r a n s p o r t a t i o n Study, n.d. 274 . Watson, P e t e r L. "Some Problems A s s o c i a t e d w i t h the Time and Cost Data used i n T r a v e l Choice M o d e l l i n g and the V a l u a t i o n of Time," u n p u b l i s h e d paper presented a t the 50th Annual Meeting of the Highway Research Board, Washington, January, 1971. W i l s o n , A.G. "Modal S p l i t , " u n p u blished paper g i v e n to the U n i v e r s i t y of London T r a n s p o r t a t i o n and Urban P l a n n i n g Seminar, October, 1965. A P P E N D I C E S APPENDIX A: STUDY REGION 2 7 5 . 276. FIRST NARROWS TRANSIT P L A N N I N G STUDY for the • ; / ' C ^ - ' '^.'[•'•'"•: •' British Columbia Department of Highways Mar eh,''?-! 967 This survey is designed to supply informati6h;.regardihg the (existing bus system and to provide guidance for future transit planning across the F i r s t Narrows Bridge; Your assistance by completing and returning this form on or'before Fr iday . March 17,  1967. will be Appreciated. NO S I G N A T U R E OR P O S T A G E IS R E Q U I R E D . Since the answers to these questions will be processed by electronic computer, '* please check only one square [7] to each q