Whenever the City Engineer installs and maintains, or causes to be installed and maintained, an official traffic signal at any intersection, he shall likewise erect and maintain at such intersection street name signs clearly visible to traffic approaching from all directions, unless such street name signs have previously been placed and are maintained at any said intersection. (Ord. 2670 § 1, 1996; Ord. 973 § 1, 1966; prior code § 19.4.4(C)).