Any motor vehicle may be operated under the conditions specified in Section 56-5-4450 when equipped with two lighted lamps upon the front thereof capable of revealing persons and objects seventy-five feet ahead in lieu of lamps required in Sections 56-5-4770 and 56-5-4790, provided that it is at no time operated at a speed in excess of twenty miles per hour.
S.C. Code § 56-5-4810