The Successful Deployment of a Transit Signal Priority System; Sumner Avenue, Springfield, Massachusetts

This paper describes how the City of Springfield Massachusetts and the Pioneer Valley Transit Authority (PVTA) have installed a first-in-the region, in-vehicle Traffic Signal Priority (TSP) system for buses on one of the City’s busiest routes. VHB/Vanasse Hangen Brustlin, Inc., the PVTA and the Pioneer Valley Planning Commission (PVPC) teamed up with the City of Springfield in order to implement this new system that had the potential to help increase on-time performance for the PVTA’s bus fleet, decrease travel times for express bus routes during rush hour, attract and retain riders and reduce congestion related emissions by decreasing idling time by PVTA buses. The system works through the use of optical-based transmitters (located on the buses), and receivers (located on the traffic signals). The transmitters emit both visible and infrared light. As the bus approaches an intersection (within approximately 400-feet), the receiver detects the optical transmission, and, based on status of the traffic signal sequence, either shortens the crossstreet’s green light, or extends the green light along the bus route. In the past, bus-prioritization systems have proved less-than-ideal operation, because they disrupted the precisely coordinated timing of the traffic signal network along the prioritized route. The system installed in the City of Springfield avoids this problem, thanks to the new algorithm that governs the signal timing. A wireless global positioning system (GPS) system installed at each cabinet maintains an accurate time reference between intersections. The system also supports an emergency-vehicle pre-emption capability, which can detect approaching emergency vehicles, and give them a green light through the intersections. These two systems co-exist at each project location. The Pioneer Valley Transit Authority serves 24 member communities in Western Massachusetts with the City of Springfield being PVTA’s largest community. PVTA, through its four different fixed route operators, runs 175 buses on 44 different routes and carries nearly 10 million passengers per year. The Springfield Area Transit Company (SATCo) operates the Green Light Special for PVTA.