South Carolina Highway 642

South Carolina Highway 642 (SC 642, also known as Dorchester Road), is a 19.292 mi state highway in the southeastern part of the U.S. state of South Carolina. It travels within the Summerville and North Charleston areas.

Route description
SR 642 runs for 19.3 mi from U.S. Route 17 Alternate (US 17 Alt.) southwest of Summerville to US 52/US 78 in North Charleston. Dorchester Road is a heavily congested highway during morning and evening traffic periods.

History
Current plans call for widening of the road from Summerville to US 17 Alternate. This has been completed.