(a) A sign may not be located in such a manner as to obscure or otherwise physically interfere with the effectiveness of an official traffic sign, signal or device, obstruct or physically interfere with the driver's view of approaching, merging or intersecting traffic.

(b) On interstate highways and controlled access highways on the primary highway system, no two sign structures shall be spaced less than 500 feet apart. Outside of villages and cities, no sign structure may be located within 500 feet of an interchange, intersection at grade, safety rest area or information center measured along the highway from the beginning or ending of pavement widening at the exit from or entrance to the main-traveled way.

(c) On other primary highways outside of villages and cities no two sign structures shall be spaced less than 300 feet apart, and within the villages and cities no two sign structures shall be spaced less than 100 feet apart.

(d) The spacing requirements of this section shall not apply to sign structures separated by buildings or other obstructions in such a manner that only one sign facing located within the above spacing distance is visible from the highway at any one time.

(e) Official and on-premises signs, and sign structures that are not lawfully maintained, shall not be counted, nor shall measurements be made from them for purposes of determining compliance with the spacing requirements.

(f) The minimum distance between signs shall be measured along the nearest edge of the pavement between points directly opposite the signs along each side of the highway, and shall apply only to structures located on the same side of the highway.