Impact of Transit Signal Priority on Bus Service Performance in Minneapolis

As part of the Urban Partnership Agreement (UPA) in Minnesota, Transit Signal Priority (TSP) was implemented on 27 signalized intersections along Central Avenue from north Minneapolis to I-694. Transit service performance before and after the TSP deployment was studied to evaluate the performance and benefit. As a result of the TSP deployment, bus schedule was reduced by two minutes to take full advantage of the conditional signal priority strategy. A wireless-based TSP algorithm previously developed by the author was installed and deployed on four buses to validate the algorithm and evaluate performance. This wireless TSP strategy considers bus location, speed and schedule adherence for priority request. A customized onboard embedded system, namely UMN TSP, was also developed to interface with radio hardware and bypass the existing onboard TSP algorithm. The objective is to validate the UMN TSP algorithm and compare its performance with existing system by taking advantage of the already instrumented onboard equipment and roadside infrastructure. Buses equipped with UMN TSP system communicates with intersection signal controllers when they are approaching and ready to pass though a signalized intersection. Link travel time and Time Point (TP) time on the TSP-equipped route segments were compared. Testing results indicated that the existing TSP implementation improves bus travel time by about 4-6%. The UMN TSP algorithm gains additional 3~6% of travel time reduction as compared to other buses operating on the same route during a two-week test period.