Stated Preference Approach for Valuation of Travel Time Displayed as Traffic Information on a VMS Board

Abstract

A stated preference (SP) approach is explored for valuation of travel time displayed as traffic information on a variable message sign (VMS) board. Two types of traffic information (called as TI-I and TI-II) are investigated and the valuation is carried out separately for private car and taxi users. Instantaneous travel time is considered as traffic information in TI-I, while instantaneous travel time along with its variation level is considered as traffic information in TI-II. The SP (choice based) data are analyzed by multinomial logit and random parameter logit (RPL) models. In RPL models, the random parameters are assumed to follow constrained triangular distribution, where mean equals its spread. The decomposition of preference heterogeneity around the mean of random parameter is also investigated in RPL models. A variation is observed in the values of travel time under TI-I and TI-II, highlighting the role of the content of VMS based travel-time information. Both travel time as traffic information and a lower variation level associated with travel time as traffic information are perceived as benefits by trip makers. The perceived benefits likely to be derived by providing travel-time information are found to be distinctly different for private car and taxi users. The study also highlights the role of modeling technique and model specification in the valuation of travel time.