Existing Problems of Transit Signal Priority on Streetcar Routes

Document Type

Journal Article

Publication Date


Subject Area

place - north america, mode - tram/light rail, infrastructure - bus/tram priority, infrastructure - traffic signals


Transit signal priority (TSP), streetcars


Transit signal priority (TSP) is a traffic control strategy that gives priority to transit vehicles by adjusting intersection signals in real time. The technology is implemented in many major cities and has proved to benefit transit routes in reducing the overall passenger travel time. Unfortunately, there are several problems with TSP that are commonly ignored. These problems are predominantly operational, such as misjudgment of the arrival time at the intersection and insensitivity to the TSP activation time. It is worsened with streetcars, which have shorter headways and thus are more prone to bunching delays. In this paper, five delay problems that streetcars experience are identified. Data are collected from a TSP-equipped intersection in the City of Toronto to provide a statistical analysis of the issues. It was found that 25.8% of times, TSP is inadequate at prioritizing public transit. From the problems raised, the most frequent one is the late arrival of a streetcar during a green interval, representing 72.5% of TSP issue cases. It was also found that TSP has a bias toward different failure cases, and favors early arrivals to the intersection. Several remedies for the defined issues are recommended. The suggestions include implementing green truncations, avoiding late TSP activation in each cycle, and introducing a prediction-based TSP system.


Permission to publish the abstract has been given by SAGE, copyright remains with them.