Known for most of its length as Potts Creek Road, the state highway runs 25.86 miles (41.62 km) from SR 311 in Paint Bank north to U.S. Route 60 (US 60) and US 220 in Covington.

SR 18 enters Alleghany County and passes through the hamlets of Potts Creek, Jordan Mines, and Boiling Spring.

At the state highway's final crossing of Potts Creek just south of its confluence with the Jackson River, the highway enters the city of Covington and becomes Indian Valley Road.

The state highway crosses over CSX's Alleghany Subdivision.

SR 18 parallels the railroad tracks north under Interstate 64 to its northern terminus at Madison Street, which carries US 60 and US 220, south of downtown Covington.