The city engineer shall place and maintain traffic-control signs, signals and devices when and as required under the traffic ordinances of this city, or as otherwise directed by action of the city council, to make effective the provisions of said ordinances, and may place and maintain such additional traffic-control devices as are necessary to regulate traffic under ordinances of the city or under state law, or to guide or warn traffic. (Ord. 5871 § 1, 2004; Ord. 5212 § 1 (Exh. E), 1999; 1957 code § 9.04.080.)