This chapter shall not apply to permanent buildings existing on the date that the ordinance codified in this chapter becomes effective; public utility poles; trees trimmed (to the trunk) to a line at least six feet above the level of the intersection; saplings, or plant species of open growth habits and not planted in the form of a hedge, which are so planted and trimmed as to leave at all seasons a clear and unobstructed cross-view; supporting members of appurtenances to permanent buildings existing on the date that the ordinance codified in this chapter becomes effective; official warning signs or signals; ornamental open fences, walls, structures or plants under three feet in height; or to places where the contour of the ground is such that there can be no cross-visibility at the intersection. (Ord. 481,, 1972.)