Model to Evaluate the Impacts of Bus Priority on Signalized Intersections

摘要

The concept of providing bus priority at signals is not new. Numerous cities haveimplemented bus priority strategies at signals with varying degree of success. Many of these cities have, however, discontinued using the priority measures. The advent of newer technology and an increased awareness for energy conservation and environmental problems due to emissions has prompted renewed interest in providing priority to buses at traffic signals. Reducing delay to the buses at signals can reduce overall travel time and improve schedule reliability. This report documents the efforts to develop a model to estimate the impacts of providing priority to buses at signalized intersections. The existing strategies to provide priority to buses were reviewed. A priority strategy compatible with the local signal controllers was developed. A model using the delay equation in the 1985 Highway Capacity Manual was developed to simulate the intersection operations with bus priority. The priority strategy was implemented in a signal controller at an intersection in College Station. Bus arrivals were simulated and priority was provided manually. The model can be a useful tool to traffic engineers to estimate the feasibility of implementing bus priority strategies. The model could encourage the increased use of bus priority measures. Better bus operations can lead to the bus being a viable alternative to the car. This in turn can lead to a reduction in vehicle miles of travel (VMT) and energy conservation, and improvement in pollution emissions.