Upon approaching an intersection, any person riding or operating a bicycle in a bicycle lane shall yield the right-of-way to all vehicles within or approaching such intersection; except, that all vehicles which must stop before entering an intersection because of a stop sign and all vehicles making a left-hand turn at an intersection shall not proceed into such intersection nor make such a turn without first yielding the right-of-way to all bicycles within or approaching such intersection, and shall proceed only when it is safe to do so. (Ord. No. 839, § 5.)