S.C. Code § 59-67-545
Parents and other adult school volunteers or employees may ride route school buses on a space available basis. Parents and other adults also may ride school buses in conjunction with special programs that are sponsored by the local school district. This use of route school buses shall be in accordance with local school district board policies and programs.
School districts may not re-route school buses in order to accommodate the pickup of adults authorized to ride school buses as provided by this section. The State is not responsible for any costs associated with parents and other adults riding school buses in conjunction with special programs. The provisions of this section shall not be construed as a waiver or abrogation of the state's limited immunity from liability and suit under the State Tort Claims Act.
S.C. Code § 59-67-545