Transit Signal Priority (TSP), one of the critical components of Bus Rapid Transit (BRT), is the key technology to enhance its operational efficacy. It does not only provide priority to the BRT vehicle, but also generate the strategy that makes a trade-off between the delay of buses at the intersection and the impacts to other traffic. This paper focuses on the design and simulation evaluation of signal priority for BRT under the conditions of mixed traffic flows. Taken the Southern Axis BRT Line 1 in Beijing as a case study, different signal priority strategies, including green extension, red truncation and special phase insertion are developed for the signalized intersection along the BRT route. A signal coordination plan is designed for the section that is composed of 4 intersections in the BRT system. The study uses the VISSIM microscopic traffic simulation model to analyze the impacts of traffic parameters, especially those of non-motorized traffic, on the effectiveness of TSP application along the BRT corridor in Beijing. Simulation results indicate that the BRT vehicles would typically benefit from transit priority with travel times savings and delay reduction as well as greater schedule adherence, and that these benefits maybe obtained with little negative impacts to overall system. It is also found that the volume of non-motorized traffic is one of the most important factors that influence the effectiveness of TSP implementation in a mixed traffic flow.
Samenvatting