The state highway runs 10.84 miles (17.45 km) from Moyer Road in Newport News east to SR 629 in Dandy.

SR 173 connects the Denbigh area of Newport News with Grafton, Seaford, and Dandy in eastern York County.

The state highway starts east through a residential area as a two-lane undivided road but expands to four lanes at Catalina Drive.

At its intersection with U.S. Route 60 (US 60, Warwick Boulevard), SR 173 gains a center left-turn lane.

At the boundary between the city of Newport News and York County, SR 173 reduces to a two-lane undivided road and its surroundings change from a suburban area to forest.