Except on such streets that form a part of the route of a primary or secondary state highway upon which the state law requires the state highway commission to install, operate, maintain, and control traffic control devices, whenever any ordinance or resolution of the City designates and describes an arterial highway, it shall be the duty of the Traffic Engineer to place and maintain a stop sign on each and every street intersecting the arterial highway. (Ord. 304 § 49, 1963).