The Traffic Bureau of the Phoenix Police Department plays a role as an element of the community policing function. The bureau is committed to contributing to the overall quality of life in the Phoenix community by the efficient use of roadways. This is done by reducing the number and severity of traffic collisions, and deterring and detecting criminal activity and traffic violations. The Traffic Bureau is structured into three units: The Traffic Enforcement Unit, The Traffic Support Unit and The Vehicular Crimes Unit. The bureau maintains a northern office along Union Hills Drive. The Phoenix Police Department is comprised of more than 3,500 officers and support personnel who protect a population of more than 1.25 million and patrol hundreds of square miles of one of the largest cities in the United States.