- Western Terminus:
- South Main Street (Warren CR 678) and Pursel Street in Phillipsburg
- Eastern Terminus:
- US 22 in Pohatcong
- 2.42 miles
NJ 122 is a short east/west route connecting US 22 in Pohatcong to Phillipsburg. It begins at US 22 and runs west along New Brunswick Avenue, which changes names after about a mile to become South Main Street. At Pursel Street in Phillipsburg, it changes designation to become CR 678. The entire length is a two-lane undivided road with traffic lights.