The city manager is authorized to place and maintain distinctive roadway markings as described in the Vehicle Code of those streets or parts of streets where the volume of traffic or the vertical or other curvature of the roadway renders it hazardous to drive on the left side of such marking or signs and markings. Such marking or signs and marking shall have the same effect as similar markings place by the State Department of Public Works pursuant to provisions of the Vehicle Code. (Prior code § 3003(f))