New Jersey Route 173

Route 173
Route information
Maintained by NJDOT
Length	14.62 mi[1] (23.53 km)
Existed	1969–present
Major junctions
West end	I-78 / US 22 in Greenwich Township
Major intersections	CR 579 in Greenwich Township I-78 / US 22 from Union Township to Franklin Township CR 513 in Franklin Township
East end	Route 31 / CR 626 in Clinton Township
Location
Country	United States
State	New Jersey
Counties	Warren, Hunterdon
Highway system
New Jersey State Highway Routes Interstate US State Scenic Byways
← Route 172 → Route 174

Route 173 is a state highway in New Jersey, United States that is a designation for an old section of U.S. Route 22 (US 22). The route runs 14.62 mi (23.53 km) from Interstate 78 (I-78) and US 22 in Pohatcong Township, Warren County to County Route 626 (CR 626, Beaver Avenue) in Clinton Township, Hunterdon County, just east of an interchange with Route 31. Route 173 parallels I-78 and US 22 for its entire length through rural areas of Warren and Hunterdon counties, passing through the towns of Bloomsbury and Clinton along the way. At one point just to the west of Clinton, Route 173 runs concurrent with I-78 and US 22.

The route was originally part of pre-1927 Route 9 from 1916 until 1927, when it became part of US 22 and Route 28. The Route 28 designation was removed from this portion of road in 1953. When I-78 was being built between exits 11 and 13 in the 1950s and 1960s, it was decided that part of US 22 would be used for the new highway. The eastbound lanes of US 22 became the westbound lanes of the new highway, the eastbound lanes of the new highway were newly constructed, and the westbound lanes of US 22 were turned into a two-lane road. In 1969, US 22 was moved to the alignment of I-78 between Pohatcong Township and Clinton Township and Route 173 was designated along most of the former alignment of US 22.