(A) The City Engineer is directed to install and maintain official traffic signals at those intersections and other places where traffic conditions are such as to require that the flow of traffic be alternately interrupted and released in order to prevent or relieve traffic congestion or to protect life or property from exceptional hazard.
(B) The City Engineer shall ascertain and determine the locations where such signals are required by field investigation, traffic counts and other traffic information as may be pertinent and his determinations therefrom shall be made in accordance with those traffic engineering and safety standards and instructions set forth in the “California Maintenance Manual” issued by the Division of Highways of the State Department of Public Works.
(C) Whenever the City Engineer installs and maintains an official traffic signal at any intersection, he shall likewise erect and maintain at such inter-section street name signs visible to the principal flow of traffic unless such street name signs have previously been placed and are maintained at any such intersection.
('81 Code, § 10.20.050)