South Carolina Highway 642
| Dorchester Road | ||||
| Route information | ||||
| Maintained by SCDOT | ||||
| Length | 19.292 mi (31.047 km) | |||
| Existed | 1939–present | |||
| Major junctions | ||||
| West end | US 17 Alt. near Summerville | |||
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| East end | US 52 / US 78 in North Charleston | |||
| Location | ||||
| Country | United States | |||
| State | South Carolina | |||
| Counties | Dorchester, Charleston | |||
| Highway system | ||||
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South Carolina Highway 642 (SC 642, also known as Dorchester Road), is a 19.292-mile (31.047 km) state highway in the southeastern part of the U.S. state of South Carolina. It travels within the Summerville and North Charleston areas.