State Highways of New Jersey

In Union Township (Hunterdon County), I-78 landed right on top of old Route 22, so NJ 173 joins it for about half a mile in each direction before splitting off. In this split section, NJ 173 actually serves as the frontage roads for I-78 for a short distance, a distinction also shared by NJ 124, the old alignment of NJ 24, as the freeway runs along the Essex-Union county line. NJDOT logs the westbound roadway of NJ 173 separately from the eastbound roadway for a while; I have combined these logs (as much as possible) below.

Mile	Street Name	Feature
14.62	Eastern terminus of , Clinton Twp, Hunterdon Co
14.62		Beaver Ave	overpass	Beaver Ave
14.56			overpass
14.50		Beaver Brook	culvert	Beaver Brook
14.42		Center St		Center St
14.21	Old Route 22	Clinton Twp, Hunterdon Co Clinton Town, Hunterdon Co
13.70	Old Route 22	Leigh St		Leigh St
13.56	Old Route 22	South Branch Raritan River	bridge	South Branch Raritan River
13.14	Pittstown Rd	west Main St		Ramp from west
13.11	Pittstown Rd			Clinton Town, Hunterdon Co Franklin Twp, Hunterdon Co
13.11	Pittstown Rd	Trib. South Branch Raritan River	bridge	Trib. South Branch Raritan River
13.04	Pittstown Rd		underpass
12.98	Ramp from east	Pittstown Rd
12.81	Ramp from east		merge
12.69		Pittstown Rd	overpass eastbound	Pittstown Rd
12.69				Franklin Twp, Hunterdon Co Union Twp, Hunterdon Co
12.37	Old Route 22	Clinton Town, Hunterdon Co Union Twp, Hunterdon Co
12.14	Old Route 22		merge
11.70	Old Route 22		merge
11.18	Rupells Rd		overpass eastbound
10.02	Old Route 22	Charlestown-Perryville Rd		Charlestown-Perryville Rd
8.98	Old Route 22	Mulhockaway Creek	bridge	Mulhockaway Creek
8.37	Old Route 22		circle	Pattenburg Rd
8.05		Union Twp, Hunterdon Co Bethlehem Twp, Hunterdon Co
5.89	Brunswick Pike	West Portal-Asbury Rd
4.33	Brunswick Pike	Railroad	underpass	Railroad
4.05		Bethlehem Twp, Hunterdon Co Bloomsbury Boro, Hunterdon Co
3.94	Old Route 22		underpass
3.39	Old Route 22	Bloomsbury Boro, Hunterdon Co Greenwich Twp, Warren Co
3.39	Old Route 22	Musconetcong River	bridge	Musconetcong River
3.34	Old Route 22	Asbury Rd
2.86	Old Route 22			Church St
2.70	Old Route 22			Warren Glen Rd
2.27	Old Route 22	Main St	overpass	Maple Dr
1.50	Old Route 22	Pohatcong Creek	bridge	Pohatcong Creek
1.41	Old Route 22	Greenwich Church Rd
1.22	Old Route 22	Branch Pohatcong Creek	culvert	Branch Pohatcong Creek
1.06	Old Route 22	Branch Pohatcong Creek	culvert	Branch Pohatcong Creek
1.02	Old Route 22	Greenwich Church Rd
0.32	Old Route 22	east	underpass	east
0.22	Old Route 22		overpass
0.00	Old Route 22		merge
0.00	Western terminus of , Pohatcong Twp | Greenwich Twp, Warren Co
	Road continues westward as