S.C. Code Ann. § 57-25-480

The Department of Transportation may provide within the right-of-way for areas at appropriate distances on which signs, displays and devices giving specific information in the interest of the traveling public may be erected and maintained under standards and regulations hereby authorized to be adopted by the department. Such standards and regulations may provide for cooperative agreements between the Department of Transportation and private interests for the use and display of brand names for FOOD, LODGING and GAS information signs on the highway right-of-way.