(A) It shall be unlawful for the driver of any vehicle to disobey the signal of any official traffic-control device placed in accordance with the provisions of this traffic code or of a traffic barrier or sign erected by any of the public departments or public utilities of the city, or any electric signal, gate, or watchman at railroad crossings, unless otherwise directed by a police officer. However, the type and the right to or necessity for such barrier or sign must be approved by the city.
(B) Such sign, signal, marking, or barrier shall have the same authority as the personal direction of a police officer.