Transit signal priority control at signalized intersections: a comprehensive review

Transit signal priority (TSP) control widely used at signalized intersections has been recognized as a practical strategy to improve the efficiency and reliability of bus operations. A proper TSP control can effectively reduce bus travel time at local arterials without significantly bringing negative impacts to the network. This paper provides a comprehensive review of TSP controls by presenting two primary sections: priority control methods and system evaluations. Based on the different types of priority strategies, the existing control methods are sub-divided into two categories: passive control and active control. Particularly, the active control is further categorized as two groups: rule-based approach and model-based one. In the review section of system evaluations, this paper presents three effective ways found in the literature: analytical evaluation, simulation test, and field test. Also to further demonstrate the effectiveness of TSP in practice, this study analyzes its field benefits in 24 cities around the world.