As used in this article:

1. (1) "Interstate system" means that portion of the national system of interstate and defense highways located within this State officially designated now or in the future by the Department of Transportation and approved by the appropriate office of the United States Government pursuant to the provisions of Title 23, United States Code, "Highways".
2. (2) "Federal-aid primary system" means that portion of connected main highways which officially are designated as the federal-aid primary highway system now or in the future by the Department of Transportation and approved by the appropriate office of the United States Government pursuant to the provisions of Title 23, United States Code, "Highways".
3. (3) "Sign" or "outdoor advertising sign" means an outdoor sign, display, device, figure, painting, drawing, message, plaque, poster, billboard, or other thing which is designed, intended, or used to advertise or inform, or any part of the advertising or its informative contents.

4. (4) An "unzoned commercial or industrial area" does not include land established as a scenic area pursuant to Section 57-25-140(D)(4) or land zoned by a subdivision of government. An unzoned commercial, business, or industrial area means the land occupied by the regularly used building, parking lot, and storage and processing area of a commercial, business, or industrial activity and land within six hundred feet of it on both sides of the highway. The unzoned land does not include:

   1. (a) land on the opposite side of an interstate or freeway primary federal-aid highway;
   2. (b) land predominantly used for residential purposes;
   3. (c) land zoned by state or local law, regulation, or ordinance except land which is zoned in a manner which allows essentially unrestricted development or where regulation of size, spacing, and lighting of signs is unrestricted or less restrictive than the restrictions imposed by Section 57-25-140;
   4. (d) land on the opposite side of a nonfreeway primary highway which is designated scenic by the commission.

5. (5) "Commercial or industrial activities" means those established activities generally recognized as commercial or industrial by zoning authorities within the State, except that none of the following are considered commercial or industrial activities:

   1. (a) outdoor advertising structures;
   2. (b) agriculture, forestry, ranching, grazing, farming, wayside produce stands, quarries, and borrow pits;
   3. (c) activities conducted in a building principally used as a residence;
   4. (d) hospitals, nursing homes, or long-term care facilities;
   5. (e) transient or temporary activities;
   6. (f) activities not visible from the main-traveled way;
   7. (g) activities more than six hundred sixty feet from the nearest edge of the right-of-way of interstate and freeway primary federal-aid highways or more than three hundred feet from the nearest edge of the right-of-way of nonfreeway primary federal-aid highways;
   8. (h) railroad tracks and minor sidings;
   9. (i) sham, prohibited, or illegal activities;
   10. (j) junkyards;
   11. (k) schools, churches, or cemeteries;
   12. (l) recreational facilities.
6. (6) "Freeway primary federal-aid highway" means a divided arterial highway for through traffic with full control of access built to the same standards as to access as an interstate highway, which is officially designated now or in the future as a part of the federal-aid primary system.