Business area means an area outside municipal limits embracing all of the land on the same side of the highway on which one or more commercial or industrial activities are conducted, including all land within one thousand feet measured in any direction from the nearest edge of the actual land used or occupied for such activity, including its parking, storage and service areas, its driveways and its established front, rear and side yards, constituting an integral part of such activity and which is zoned, under authority of law, primarily to permit industrial or commercial activity. However, when one or more commercial or industrial activities are located within one thousand feet of a freeway interchange, the business area shall extend three thousand feet measured in each direction parallel to the freeway from the center line of the crossroad, but shall not extend beyond the limits of the established commercial or industrial zone.