Officers of the police department and Parking Aides are hereby authorized to direct all traffic by means of visible or audible signal. It shall be unlawful for any person to refuse or fail to comply with any lawful order, signal or direction of traffic or police officer, or at any regular established school crossing, to refuse to or fail to comply with any order, signal or direction of any person appointed by the Chief of Police to control traffic at school crossings, provided that such person giving any order, signal or direction at such school crossing shall at all times be wearing some insignia indicating such appointment.
The Chief of Police is hereby granted the power to determine the streets and intersections on which, and the time at which movement of traffic shall be directed.