The city traffic engineer is authorized to place and maintain distinctive roadway markings as described in the Vehicle Code on 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 markings shall have the same effect as similar markings placed pursuant to provisions of the Vehicle Code. (Prior code § 25.02.034)