Transit signal priority project, phase II

Transit Signal Priority (TSP) is recognized as an emerging technology that is capable of enhancing traditional transit services. Basic green-extension TSP was implemented on U.S. Route 1 in the Northern Virginia Area (or Washington, DC metropolitan area). This study quantifies the impact of TSP technology on transit-vehicle performance using field-collected Global Positioning System (GPS) data and evaluates the system-wide benefits of TSP operations using computer simulations to expand on the field evaluation study. The field study demonstrated that overall travel-time improvements in the order of 3% to 6% were observed for TSP-operated buses. However, the results also demonstrated that green-extension TSP can increase transit-vehicle travel times by approximately 2.5% during congested morning peak periods. In addition, the study demonstrated that TSP strategies reduce transit-vehicle intersection delay by as much as 23%. The field study demonstrated that the benefits associated with TSP were highly dependent on the roadway level of congestion and were maximized under moderate to low levels of congestion. However, the simulation results indicated that TSP did not result in statisti