Optimal emergency rescue route for traffic accident considering variable travel time

Traffic accidents have adverse effect on urban road network and can easily cause traffic congestion or even secondary accidents. Improving response efficiency plays a core role for emergency management of traffic accidents. The optimization of rescue route is necessary for saving travel time of emergency rescue vehicle on the way. To minimize the total travel time of rescue vehicle, variable travel time on links and at intersections are analyzed. Each link is divided into three parts including an accelerating area, free speed area, and queuing area, respectively. The link travel time is determined by the traffic conditions and existence of isolation belt, while the intersection travel time is decided by traffic lights. A case study illustrates the effectiveness of the proposed model.