In 2007, the Legislature allowed the signs marking the primary state highways to be changed from the old black-and-white to the new blue-and-white design, which features an outline of the state, the Palmetto Tree & Crescent symbol from the state flag, and the words "SOUTH CAROLINA" spelled out along on the top of the highway shield. South Carolina uses a wide shield for all routes, the width most states use only for three-digit routes. The former shield was a simple white rectangle with a black border, with the letters "S.C." on top.
South Carolina has both a "state highway primary system" and a "state highway secondary system." The numbering pattern for routes in the secondary system is S-xx-yy, where "xx" is the county code and "yy" is the highway number, and the secondary highway sign is a small wide black sign with white characters. Routes in the primary system are listed below.
The South Carolina Department of Transportation Ferry Division a.k.a. South Carolina Ferry System is a branch of SCDOT that is responsible for the operation of over two dozen ferry services that transport passengers and vehicles to several islands along the James Island outside of Charleston in South Carolina.