All traffic-control signs, signals and devices shall conform to the manual and specifications approved by the Department of Highways or to resolution adopted by Council. All signs and signals required under the Traffic Code for a particular purpose shall, so far as practicable, be uniform as to type and location throughout the city. All the traffic-control devices so erected and not inconsistent with the provisions of state law or the Traffic Code shall be official traffic-control devices.
(1986 Code, § 305.04)