S.C. Code § 5-27-170
In any county and beyond the borders of any incorporated city or town and within a radius of five miles of any city having a population of fifty thousand or more, the city engineer of such city and the county engineer of such county may change the name of any street or road. Any such change of name when made shall be certified to the office of the clerk of court of common pleas and general sessions or of the register of deeds for such county, there to be recorded. In any county having no county engineer the executive officer of the county department or agency having jurisdiction of the construction and maintenance of county roads and highways shall act in his stead. But the city engineer of a city that had a population of more than sixty thousand and less than seventy thousand according to the 1940 United States census shall not have the right to change the names of streets that lie outside the county in which the city hall of such city is located.
S.C. Code § 5-27-170