(a) No obstructions, such as structures, fences, parking or vegetation shall be permitted in any business, manufacturing or institutional district between the heights of two (2) feet and ten (10) feet above the plane through the centerline of the road within the triangular space formed by any two existing or proposed intersecting street or alley right-of-way lines and a line joining points on such lines located a minimum of fifteen (15) feet from the road right-of-way (See illustration No. 2).

(b) In the case of any federal, state or county highway or town road intersection with any other federal, state or county highway or town road or railways, the corner cutoff distances establishing the triangular vision clearance space shall be increased to fifty (50) feet. [Code § 12.13-1.]