S.C. Code Ann. § 57-3-670

The department may cooperate and enter into contracts with the Federal Highway Administration 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.