Passenger travel time and path choice implications of real-time transit information

Abstract

This paper considers information systems in public transit in which the passenger receives information in real time regarding projected vehicle travel times. Such information systems may have value to passengers in situations where they may choose among different origin-to-destination paths. To provide a preliminary assessment of these systems, an analytic framework is presented to evaluate path choices and travel time benefits resulting from real-time information. A behavioral model of transit path choice is presented that frames the choice in terms of a decision whether to board a departing vehicle. Furthermore, this path choice model accommodates network travel times that are both stochastic and time-dependent, two elements that have been neglected in previous studies but are critical to evaluating real-time information systems. The path choice model is extended to demonstrate how real-time information may be incorporated by the passenger in making a path choice decision. This analytic framework is applied to a case study corridor at the Massachusetts Bay Transportation Authority (MBTA), using a computer simulation to model vehicle movements and passenger path choices in the corridor. The results suggest that real-time information yields only very modest improvements in passenger service measures such as the origin-to-destination travel times and the variability of trip times. Based on this analysis, the quantitative benefits of real-time information for transit passenger path choices appear to be questionable.