0 A Discrete-Continuous Choice Model with Perfect and Imperfect Substitutes Abdul Rawoof Pinjari Associate Professor University of South Florida Department of Civil and Environmental Engineering 4202 E. Fowler Ave, ENB 118, Tampa, Florida 33620 Tel: (813) 974-9671; Fax: (813) 974-2957 Email: apinjari@usf.edu Vijayaraghavan (Vijay) Sivaraman University of South Florida Department of Civil and Environmental Engineering 4202 E. Fowler Ave, CUT 230, Tampa, Florida 33620 Tel: (813) 974-7165; Fax: (813) 974-2957 Email: sivaraman@cutr.usf.edu Note: This paper is currently in review with Transportation Research Part B.