Determination of Optimal Detector Location for Transit Signal Priority with Queue Jumper Lanes

Transit signal priority (TSP) is an operational strategy that facilitates movement of transit vehicles through signalized intersections. As an important component of a TSP system, the transit vehicle detection system plays a key role in determining when to trigger TSP and which TSP strategy to use. This paper presents an analytical method to determine optimal detector locations for intersections implemented with TSP and queue jumper lanes. A queue jumper lane is a preferential treatment for buses that designates a short stretch of a special lane, such as a right-turn bay, to allow buses to bypass a traffic queue and then to proceed ahead of the queue by means of an early green signal for that lane. In this study, a comprehensive TSP strategy was used that considers early green, green extension, special phase insertion, coordination recovery, green reimbursement, and maximum number of continuous TSP requests. An analytical method for determining optimal detector locations under this TSP strategy for different bus arrival conditions was proposed. The effectiveness of the proposed method was verified with the VISSIM microsimulation model, and results show that the method is able to identify optimal bus detector locations for TSP with queue jumper lanes.