A Multiple Dispatch Queueing Model of Police Patrol Operations

One of the primary concerns of urban police departments is the effective use of patrol cars. In large cities, police assigned to patrol cars typically account for more than 50% of total police manpower and their allocation has become particularly crucial in light of recent fiscal cutbacks. The police patrol system is a complex multi-server queueing system, and recently many urban police departments have been using queueing models to estimate delays in responding to calls for police assistance. The magnitude of these delays is usually one basis for measuring system efficiency as well as for determining allocations of patrol cars among precincts. A major limitation of these models is that they assume that only a single unit is dispatched to each call. In general, this is not the case, particularly in police departments with one-officer patrol cars. This paper describes a model that has been developed to represent patrol car operations more accurately. It is a multi-priority queueing model that explicitly reflects multiple car dispatches. Its purpose is not only to provide a better basis for the efficient allocation of patrol cars, but to enable police officials to gauge the effects of policies, such as one-officer patrol cars, which affect the number of cars dispatched to various types of incidents.