Transit Signal Priority: Proposing a Novel Algorithm to Decrease Delay and Environmental Impacts in BRT Route Intersections

Document Type: Research Paper


1 Department of Transportation Engineering, Isfahan University if Technology, Iran

2 Department of Civil Engineering, Isfahan University of Technology, Iran

3 Department of Transportation Engineering, Isfahan University of Technology, Iran

4 School of Civil and Environmental Engineering, University of New South Wales, Sydney, Australia



Intersections are considered as the most critical parts of the bus rapid transit (BRT) system. Transit signal priority is one of the efficient solutions to reduce BRT fleet delays at intersections. The aim of this study is to propose a new algorithm to decrease the BRT fleet delays at actuated intersections, while reducing the negative impacts on different approaches. The adaptive strategy is applied in this study. In the proposed algorithm, named TSPAT (Transit Signal Priority for Actuated Timing), intersection phasing is rescheduled, based on traffic conditions such as phase conditions at the time of bus arrival, the queue length of other approaches, and prioritization record in a specific time length. To assess the merits of the proposed algorithm, a before-after study is executed by applying VISSIM traffic simulation software for an actuated intersection in Isfahan city, Iran. The simulation results show that by applying the algorithm, the average delay of BRT fleets is declined by 21 % and 51% in peak and off-peak hours, respectively. Furthermore, the average speed of BRT fleets is increased by 26% and 78%, during peak and off-peak hours, respectively. The utilization of TSPAT algorithm can improve the desirability of the public transportation system along the BRT routes.


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