Using real-time data to improve reliability on high-frequency transit services

Abstract

In recent years, automatically-collected data from many transit agencies have been made available to the public in real time. This has dramatically improved the experience of riding transit, by allowing passengers to use detailed information on the current state of service to make more informed travel decisions. The "open data" movement has allowed independent mobile-phone app developers to create a variety of useful tools to improve the passenger experience. However, agencies' use of real-time data for operational purposes has lagged behind customer-facing app development. This research examines the use of real-time data for the application of operational control strategies on transit services. Two high-frequency bus routes of the Massachusetts Bay Transportation Authority are used as a case study. It begins with the development of an application to download, interpret, and present data on bus service and recommended control actions in a graphical user interface. This application is then used to conduct an experiment with a terminal-based holding strategy on MBTA Route 1. The results of this experiment drive further investigation into the causes of deviations from scheduled or assigned departure times at terminals. To supplement the experimental data, a simulation model of MBTA Routes 1 and 28 is developed. This simulation is used to test additional control strategies, as well as the effect of reducing unexplained operator deviations from assigned departure times. The research finds that real-time data can be used to create significant operational improvements. In particular, holding strategies at terminals, along with reducing unexplained operator deviations from assigned terminal departure times, have a strong effect. Several specific recommendations are made for a number of strategies that the MBTA can use to improve the precision of terminal departure times on bus services. This research also finds that holding at midpoints and short-turning can provide some additional benefit, but the costs and benefits to passengers of these strategies are more complicated and should be investigated with further research and implemented using optimization schemes rather than the heuristic rules used here.