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 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. (2003 Code § 10-03-01)