S.C. Code Ann. § 58-23-590
(C) The commission shall issue a common carrier certificate or contract carrier permit of public convenience and necessity if the applicant proves to the commission that:
(2) the proposed service, to the extent to be authorized by the certificate or permit, is required by the present public convenience and necessity.
The commission shall adopt regulations that provide criteria for establishing that the applicant is fit, willing, and able, and criteria for establishing that the applicant must meet the requirement of public convenience and necessity. The determination that the proposed service is required by the public, convenience and necessity must be made by the commission on a case by case basis.