A "clear vision triangle", as defined in section 11-9-2 of this title, shall be maintained on the corners of all public and private property within the intersection of roadways or of a roadway and railroad. The clear vision area shall contain no trees, shrubs or other plantings, nor any fences, walls, signs or other temporary or permanent sight obstructions of any nature exceeding thirty inches (30") in height above the existing centerline elevation of the adjacent roadway, except that trees exceeding thirty inches (30") in height may be permitted if all branches and foliage be removed to a height of nine feet (9') above the existing centerline of the adjacent roadway. (Ord. A-407, 3-15-1982; amd. Ord. 05-25, 11-21-2005)