South Carolina Highway 642

South Carolina Highway 642
South Carolina Highway 642
Dorchester Road
Route information
	Maintained by SCDOT
Length	19.292 mi (31.047 km)
Existed	1939[citation needed]–present
Major junctions
West end	; US 17 Alt. near Summerville
	I-526 in North Charleston; I-26 in North Charleston;
East end	US 52 / US 78 in North Charleston
Location
Country	United States
State	South Carolina
Counties	Dorchester, Charleston
Highway system
	South Carolina State Highway System; Interstate; US; State; Scenic;

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.

Route description

SR 642 runs for 19.3 miles (31.1 km) from U.S. Route 17 Alternate (US 17 Alt.) southwest of Summerville to US 52/US 78 in North Charleston.^[3] Dorchester Road is a heavily congested highway during morning and evening traffic periods.^{[citation needed]}

History

Current plans call for widening of the road from Summerville to US 17 Alternate. This has been completed.^[4]

Major intersections

County	Location	mi^[1]^[2]	km	Destinations	Notes
Dorchester		0.000	0.000	US 17 Alt. (US 17 Alt. Truck begins) – Walterboro, Bamberg, Summerville	Western end of US 17 Alt. Truck concurrency; western terminus of SC 642; southern terminus of US 17 Alt. Truck
Dorchester		2.832	4.558	SC 165 (Bacons Bridge Road / US 17 Alt. Truck north) – Summerville, Charleston	Eastern end of US 17 Alt. Truck concurrency
Charleston	North Charleston	16.542– 16.602	26.622– 26.718	I-526 (Mark Clark Expressway) – Mt. Pleasant, Savannah, GA	I-526 exit 15
		18.602	29.937	I-26 – Columbia, Charleston	I-26 exit 215
		19.292	31.047	US 52 / US 78 (Rivers Avenue)	Eastern terminus
1.000 mi = 1.609 km; 1.000 km = 0.621 mi