New Jersey Route 173

New Jersey State Highway 173 is a state highway in New Jersey, United States. It is an old section of United States Highway 22 from Greenwich Township, Warren County, New Jersey at an intersection with Interstate 78 to Clinton Township, New Jersey at an intersection with New Jersey State Highway 31.

When I-78 was being built in the area, it was decided that part of US 22 would be used for the new highway. What eventually happened was that 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 became NJ 173. US 22 and I-78 were then multiplexed on the new highway.

The section of Alternate US 22 that ran from the point where NJ 173 ends to Union Square, Phillipsburg, NJ was renamed NJ 122.

In Easton, Pennsylvania, Northampton Street became PA 248.