The following should be a good starting point:

Small, Kenneth A. and Verhoef, Erik T. 2007. The Economics of Urban Transportation. London and New York: Routledge.

This book is the second edition of the classic Urban Transportation Economics, 1992. Description can be found in the publisher's website: http://www.routledge.com/9780415285155

Website of Kenneth A. Small: http://www.socsci.uci.edu/~ksmall/