Online Dispatching and Routing Model for Emergency Vehicles with Area Coverage Constraints

Abstract

Response time plays a crucial role in reducing the loss of assets and lives caused by emergencies. Good dispatch strategies for emergency response vehicles result in more efficient service, and route guidance can help reduce vehicles’ travel times. Because of a limited number and type of emergency response vehicles at each station, service area gaps will be created: they cannot be properly covered by the remaining emergency response vehicles when some vehicles are dispatched. Future emergency calls in these areas may experience longer response times than usual. In this paper, an optimization model is developed that, given real-time traffic information, can assist dispatchers of emergency response vehicle in assigning multiple emergency response vehicles to incidents and in determining the routes that avoid congestion spots in the transportation networks. This model accounts for the service area coverage concerns (when several vehicles are busy) by relocation and redistribution of the remaining vehicles among stations. The results show that coordination of different types of vehicles, relocation of vehicles for better area coverage, and use of a time-dependent shortest path algorithm in this model significantly improve the performance of the emergency response system.