Bus detector location is significant for transit signal priority (TSP) system. Either too close or too far location would reduce the effectiveness of TSP due to failure of triggering TSP or erroneous prediction of bus arrival time. To address this issue, this paper proposes a method to optimize the detector locations of multi-step detection system. Within the method, the forecast detector location is optimized by maximizing bus passing rate considering different arrival conditions, and confirmation detector location is optimized by reducing the factors that lead to bus speed fluctuation. To validate the proposed method, experiments are carried out on VISSIM. Results show that the optimal location of forecast and confirmation detector are around 450m and 100m from the intersection. The values provided by our method are 460m and 92m, which matches the simulation results. Generally, this method could guarantee both timely trigger of TSP and accurate prediction of bus arrival time, thus improving the service effectiveness of TSP.

transit signal priority;multi-step detection;detector location