Traffic Signal Timing For Ambulance Preemption

Ambulance has a very important role to play in saving lives. However, in some cases there will be some delay caused by the ambulance driver because of his concerns and other factors, which caused a loss of people's lives. Let the ambulance through the intersection without any delay by changing the traffic signal timing, meanwhile, try the best to reduce the time delay on other vehicles, will be one of the effective way to alleviate urban traffic problems and improve people's living standards.In this paper, the single intersection which has signal control is adopted as control object, explore and study the traffic signal timing for ambulance preemption. It is supposed that the intersection sets up traffic detectors, which can detect information of ambulance and other traffics, at the same time these detectors transmit the information to the controller. Before the ambulance arrived, according to different traffic flow in all directions of the intersection, the shortest distance was determined. Subsequently, the dynamic equations were builded according to the coming vehicles and other informations, by solving the dynamic time-invariant system, the optimal control parameters is generated, thus make it possible to restore nomal traffic flow in a short time. Finally, we did some simulation of fixed signal timing and the signal timing we used in this paper separately. The results show that the signal timing we used in this paper can save time in all directions of the intersection compared with fixed signal timing. These studies can provide a theoretical basis and reference value to solve urban traffic problems related in future.