Planning Corridors for Transit Signal Priority While Considering Pedestrian Delay

About the report:

This research study consisted of developing a decision-support tool for Transit Signal Priority (TSP) implementation for Virginia corridors. TSP is a measure to temporarily modify signal timings to prioritize transit vehicle movement and improve performance at signalized intersections. The study included an in-depth literature review, criteria identification, table development and review, tool development and application, simulation, and verification. TSP-related manuals were reviewed to develop the Transit Signal Priority Recommendation Tool (TSPRT). TSPRT includes 19 characteristics in 5 categories: geometric, transit, pedestrian, traffic, and signal characteristics.

TSPRT was applied to corridors in Charlottesville, Blacksburg, and Arlington. Microscopic simulation was used to address the impact of TSP implementation. Results indicated that among these three corridors, Columbia Pike in Arlington would be best suited for TSP implementation. Columbia Pike had a medium score for TSP where Blacksburg and Charlottesville had low scores for successful TSP implementation. The higher the TSPRT score, the more viable TSP is for implementation.

A higher TSPRT score does not necessarily imply higher reductions in delay due to the implementation of TSP. Instead, the impact of TSP depends on the target area’s characteristics and can be measured through the use of microsimulation, which indicated substantial benefits for buses and traffic in the same direction as buses. However, a trade-off was evident between the TSP direction and the non-TSP direction in terms of overall delay. Nevertheless, from the perspective of delay for transit passengers, TSP could reduce overall passenger delay, because the number of passengers on a bus is generally higher than the number of passengers in a passenger vehicle. The simulated effect of TSP on crossing pedestrians was negligible. In order for TSP to have a meaningful impact on pedestrians, higher volumes of crossing pedestrians and more frequent TSP activations would be required. In smaller towns such as Blacksburg or Charlottesville, TSP would not impact pedestrians substantially.

The study recommends that 1) the Virginia Department of Rail and Public Transportation’s Public Transportation Division should consider which of its business processes could benefit from the incorporation of the TSPRT and 2) the Virginia Department of Transportation’s Transportation and Mobility Planning Division and/or the Department of Rail and Public Transportation’s Public Transportation Division should disseminate information regarding the use of the TSPRT tool to Virginia metropolitan planning organizations and localities. The benefit of TSPRT may be more efficient budget allocation, by supporting programs such as project prioritization processes.

Authors