Optimizing Conflicting Transit Signal Priority Requests: Application to an Isolated Intersection

Abstract

This study proposes a method to resolve multiple conflicting transit signal priority (TSP) requests at signalized intersections. The proposed method is unique in two ways. First, the performance of TSP requests is pre-evaluated to guarantee the benefits and efficiency of TSP. Second, a serving sequence model is developed to resolve conflicting TSP requests, and this model consists of two critical modules: conflict identification and priority ranking. The proposed method is applied to an intersection with multi-TSP requests. Results show that the proposed method significantly outperforms the "no priority" (baseline case) and the conventional first-in-first-service (FIFS) policy in terms of bus delay and associated impacts on other vehicular traffic. The average bus delay is reduced by more than 13.6% over the baseline case, and 7.5% over the FIFS strategy; and the delay of passenger vehicles is 3.8% and 2.5 % lower than than the baseline case and FIFS policy, respectively.