It shall be the duty of the officers of the police department, or any officers that are so assigned by the chief of police, to enforce all street traffic laws of the city and all the state vehicle laws applicable to street traffic in the city. Officers of the department shall make arrests for traffic violations, investigate accidents, and cooperate with other officers in the administration of the traffic laws and in developing ways and means to improve traffic conditions, and to carry out those duties specially imposed upon the department by this title and any traffic ordinances of the city. (2000 Code § 15-201)