(A)   (1)   The Chief of Police, by and with the approval of the City Traffic Engineer, is hereby empowered to make regulations necessary to make effective the provisions of the traffic laws of the city, and to make and enforce temporary or experimental regulations to cover emergencies or special conditions.
      (2)   No such temporary or experimental regulation shall remain in effect for more than 90 days.
   (B)   The City Traffic Engineer may test traffic- control devices under actual conditions of traffic.
   (C)   (1)   The Chief of Police may authorize the temporary placing of official traffic-control devices when required by an emergency.
      (2)   The Chief of Police shall notify the City Traffic Engineer of his or her action as soon thereafter as is practicable.
(1999 Code, § 70.64)