In this section, “centerline” means: The centerline of the main traveled way of a nondivided highway; or A line equidistant from the edges of the median separating the main traveled ways of a divided highway. The location of an outdoor sign structure located between highways entering into or intersecting the main traveled way of any federal-aid primary highway shall conform to the minimum spacing criteria specified in this section, to be applied separately to each side of the federal-aid primary highway. If the distance between the centerlines of intersecting highways is less than 1,000 feet, a maximum of three sign structures, whether double-faced, back-to-back, or v-type, may be permitted between the intersecting highways, and the minimum spacing between the structures shall be 100 feet. If the distance between the centerlines of intersecting highways is 1,000 feet or more, the minimum spacing between sign structures, whether double-faced, back-to-back, or v-type, shall be 300 feet. For purposes of this subsection, the following rules apply. Alleys, undeveloped rights-of-way, private roads, and driveways may not be regarded as intersecting highways. Only highways that enter directly into the main traveled way of the federal-aid primary highway may be regarded as intersecting. Official and “on premise” signs, as defined in Title 23, § 131(c) of the United States Code, may not be counted, and measurements may not be made from them for purposes of determining compliance with the spacing requirements. The minimum distance between signs shall be measured along the nearest edge of the pavement between points directly opposite the signs. The minimum spacing criteria specified in this section do not apply to sign structures separated by a building or other obstruction so that only one sign structure is visible from any one place on the main traveled way.