S.C. Code Ann. § 57-19-10: Levy of special county tax for roads.

The governing body of each county may levy annually a sum not exceeding one mill on all the taxable property of the respective counties, which shall constitute a part of the county road fund, to be expended by the governing body in the same manner as is provided by law for the use and expenditure of the commutation tax. Such tax shall be collected at the same time and in the same manner as is provided by law for the collection of taxes levied for ordinary county purposes.