Light Rail Transit is a railway system which can drive on the street. For enhancing the operation performance, a preemption signal system should be installed for Light Rail Transit to pass the traffic signal without stop. The installation of a preemption signal has to consider the geometric condition, the stop location and the traffic situation. This paper presents a simulation result of the preemption signal performance of different control strategies under various intersection conditions and traffic situations. The location of detectors will influence the traffic performance. The results can be taken as reference when constructing a Light Rail Transit.