All traffic control signals, signs, and traffic control devices to be erected or maintained upon any City street designated as forming a part of the route of a primary state highway or secondary state highway must be approved by the Director of Highways prior to their installation; provided, however, traffic control signals, signs, and traffic control devices are subject to approval of the Director of Highways for installation and type only. All signs and signals required hereunder for a particular purpose shall so far as practicable be uniform as to type and location throughout the City. All traffic control devices so erected and not inconsistent with the provisions of state law or this title shall be official traffic control devices. [Code 1970 § 10.20.020; Code 1954 § 8-12.08.]