(A)   It shall be the duty of the Police Department to enforce the street traffic regulations of this city and all state vehicle laws applicable to street traffic in this city, to make arrests for traffic violations, to investigate all traffic accidents, to cooperate with other officers of the city in the administration of the street traffic laws and in the development of ways and means to improve traffic conditions, and to carry out those duties specially imposed by this traffic code and other traffic ordinances which may be passed by the city.
('75 code, § 40.5)
   (B)   It shall be the duty of the Chief of Police, and to this end he shall have the authority to:
      (1)  Coordinate traffic activities, supervise preparation and publication of traffic reports, receive complaints relating to traffic matters, and recommend to Council ways and means of improving traffic conditions and the administration and enforcement of traffic regulations.
      (2)   Determine the installation and proper timing and maintenance of traffic-control devices, conduct engineering analyses of traffic accidents and devise remedial measures, conduct engineering investigation of traffic conditions, and cooperate with other city officials in the development of ways and means to improve traffic conditions.
      (3)   Supervise the installation of all traffic controls, devices, or signs required by the ordinances of the city and the provisions of this code or the resolutions adopted by the Board of Public Works and Safety.
      (4)   Cause to be removed and supervise the removal of all traffic-control devices or signs not installed in accordance with the ordinances of the city, the provisions of this code, the resolutions of the Board of Public Works and Safety, or the laws of the state.
('75 Code, § 40.10)
   (C)  The Chief of Police, with the approval of the Board of Public Works and Safety, is hereby empowered to make temporary regulations necessary to make effective the provisions of the traffic code of this city and to make and enforce temporary or experimental regulations to cover emergencies or special conditions.  No temporary or experimental regulation shall remain in effect for more than 90 days.
   (D)   The Chief of Police may test traffic-control devices under actual conditions of traffic.
('75 Code, § 40.11)