303.07 AUTHORITY OF POLICE AND FIRE DEPARTMENT OFFICIALS.
   It shall be the duty of the officers of the Police Department, or such officers as are assigned by the Chief of Police, to enforce all street traffic laws of the City and all of the State vehicle laws applicable to street traffic in the City.
   Officers of the Police Department, or such officers as are assigned by the Chief of Police, are hereby authorized to direct all traffic by voice, hand or signal in conformance with traffic laws, provided that in the event of a fire or other emergency or to expedite traffic or to safeguard pedestrians, officers of the Police Department may direct traffic as conditions may require, notwithstanding the provisions of the traffic laws.
   Officers of the Fire Department, when at the scene of a fire, may direct or assist the police in directing traffic thereat or in the immediate vicinity. (1947 Code §19.4)