S.C. Code Ann. § 56-11-410: Imposition and calculation of tax; effect of other motor carrier taxes; Infrastructure Maintenance Trust Fund.

(A) A road tax for the privilege of using the streets and highways in this State is imposed upon every motor carrier. The tax is equivalent to the user fee imposed pursuant to Section 12-28-310, calculated on the amount of gasoline or other motor fuel used by the motor carrier in its operations within this State. Except as credit for certain taxes as provided for in this chapter, taxes imposed on motor carriers by this chapter are in addition to taxes imposed upon the carriers by any other provision of law.

(B) Notwithstanding any other provision of law, all of the road tax funds collected in excess of sixteen cents a gallon after accounting for the credit provided in Section 56-11-450, must be credited to the Infrastructure Maintenance Trust Fund.