Simulation of the effects of intermodal transfer penalties on transit use

In recent times, die planning, analysis, and design of intermodal transfer facilities have been receiving increasing attention as planners attempt to overhaul public transportation systems that are losing ground to the ubiquitous automobile. However, recent research indicates that modeling tools currently used in practice do not adequately account for the effects of transfer penalties on transit ridership and network performance. In an attempt to fill this research need, transit system performance is simulated under different scenarios of intermodal and intramodal transfers. Using a controlled experimental design, transit ridership and system performance are simulated within a traditional four-step travel modeling framework assuming a variety of network configurations characterized by different transfer scenarious. Results show that the presence of a transfer on a transit line can substantially reduce transit ridership and that the extent of this reduction is highly dependent on the type of transfer encountered, that is, whether the transfer is intermodal (across different modes) or intramodal (within the same mode). The implications of the study results on the planning of intermodal transit systems are discussed in detail.