No sign shall be permitted at the intersection of any street in such a manner as to obstruct free and clear vision of motor vehicle operators or at any location where by reason of its position, shape or color it may interfere with or be confused with any authorized traffic sign, signal or device or which makes use of a word, symbol, phrase, shape or color in such a manner as to interfere with, mislead, or confuse traffic. (Prior code § 3.08.151)15.148.620