It shall be the duty of the police department to enforce the street traffic regulations of this City and all of the State vehicle laws applicable to street traffic in this City, to make arrests for traffic violations, to investigate traffic accidents and to cooperate with other officers of the City 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 said division by this Title and other traffic ordinances of this City. (Ord. 155 NS § 2, 1967; prior code § 513-8.)