All traffic-control signs, signals, and devices shall conform to the specifications approved by the State Highway Administration. All signs and signals required hereunder for a particular purpose shall so far as practicable be uniform as to type and location throughout the County. All traffic-control devices so erected and not inconsistent with the provisions of State law or this subtitle shall be official traffic-control devices. All traffic control signal monitoring systems equipment shall conform to the requirements of the Transportation Article, Annotated Code of Maryland.