The application of the actuated signal control at urban intersections is an important measure to ensure the advantages of modern streetcars in energy saving,environment protection,comfort and efficiency.Aiming at the problem of the installation site of vehicle arrival detectors at intersections,a design method of the detector position is proposed for the modern streetcars with priority control at intersections.First,according to the priority control strategy of the modern streetcars at intersections and their arrival time at stop lines,the situations of the modern streetcars waiting for green lights are divided into seven types,and the calculation methods for the waiting time of green lights are respectively put forward.Next,by analyzing the displacement relationships among detectors,stops and upstream adjacent intersections,a computing model for the detector position is constructed.Finally,the validi- ty and feasibility of the proposed design method are testified by using the planning data and current traffic real-time data of Nanjing Hexi modern streetcars.The results show that the proposed design method is practical,and it has a good prospect for engineering applications.