Whenever any ordinance or resolution of this city designates any one-way street or alley, the city engineer shall place and maintain signs giving notice thereof, and no such regulations shall be effective unless such signs are in place. Signs indicating the direction of lawful traffic movement shall be placed at every intersection where movement of traffic in the opposite direction is prohibited.  (Ord. 486 § 4 (part), 1992:  prior code § 13-5.2)