Generalized Hypercube Queueing Model for Locating Emergency Response Vehicles in Urban Transportation Networks

Emergency response systems in urban areas should be located in such a way to ensure adequate coverage as well as a rapid response time. We developed a model for locating emergency vehicles on urban networks based on a generalization of the Hypercube Queuing Model. The proposed model considers spatial and temporal characteristics of demand such as the possibility that a server is not always available when its service is required, and the service rates are not identical and may be variable both among servers and incident characteristics. The model is applied for locating tow-away vehicles on the I-80 freeway in the San Francisco Bay Area and the results are compared with existing coverage and median models. The results show an improvement in the mean response time especially in cases of high demand for intervention.