S.C. Code Ann. § 56-5-2715: Stop required at designated railroad grade crossings.

The Department of Transportation, and local authorities with the approval of the Department of Transportation, may designate particularly dangerous highway grade crossings of railroads and erect stop signs thereat. When such signs are erected, the driver of any vehicle shall stop within fifty feet, but not less than fifteen feet, from the nearest rail of the railroad and shall proceed only upon exercising due care.