S.C. Code Ann. § 57-3-670
The department may cooperate and enter into contracts with the United States Bureau of Public Roads and do any and all things necessary to carry out the provisions of any Federal-Aid Highway Act, including, but not limited to, the planning, construction, and maintenance of federal-aid highways, access roads, flight strips, and all other eligible projects, regardless of whether such projects are a part of the state highway system and may condemn or otherwise acquire lands necessary for rights-of-way in connection therewith under the procedure prescribed by law in condemning and acquiring lands for state highway purposes.