Assessment of intermodal transfer penalties using stated preference data

Since the passage of the Intermodal Surface Transportation Efficiency Act of 1991 there has been an increasing interest in the planning and design of an intermodal passenger transportation system. It has long been recognized that modal transfer has a certain penalty associated with it. The recent surge in intermodal planning merits an in-depth examination and accurate measurement of the penalties associated with transfers between modes. Current planning procedures usually involve an ad hoc treatment of transfer penalties based on various assumptions of wait time and value of time. To better assess the disutility associated with modal transfers, discrete choice models are used to quantify transfer penalties and their effects on mode choice in different transfer contexts. Revealed and stated preference data from the New York-New Jersey commute corridors are used to estimate logit models of mode choice reflecting the impacts of modal transfers. The model results suggest that the penalty factor associated with transfer time should be higher than that traditionally used in travel demand models and that the value of the transfer penalty varies according to the type of modal transfer.