New Jersey Route 31

Route 31
Route 31 highlighted in red
Route information
Maintained by NJDOT and City of Trenton
Length	48.9 mi[1] (78.7 km)
Existed	1967–present
Major junctions
South end	US 206 / US 1 Bus. in Trenton
Major intersections	I-295 in Hopewell Township US 202 in East Amwell Route 179 in East Amwell US 202 / Route 12 in Flemington I-78 / US 22 in Clinton Township Route 173 in Clinton Township Route 57 in Washington
North end	US 46 in White Township
Location
Country	United States
State	New Jersey
Counties	Mercer, Hunterdon, Warren
Highway system
New Jersey State Highway Routes Interstate US State Scenic Byways
← US 30 → Route 32
← Route 68 Route 69 → Route 70

Route 31 is a state highway in New Jersey, United States. It runs 48.93 miles (78.75 km) from US 206/US 1 Bus. in Trenton, Mercer County, north to an intersection with US 46 in the Buttzville section of White Township, Warren County. Along the way, Route 31 heads through the communities of Flemington, Clinton, and Washington. Most of the highway is state-maintained; however, the section within the city limits of Trenton is maintained by the city. Much of Route 31 is a two-lane highway that passes through farmland, woodland, and mountainous areas. Two portions of the route—from Trenton to Pennington and from Ringoes to Clinton—consist of more development.

The highway was constructed from 1926 to 1935. Route 31 has carried two different numbers in the past. It was known as Route 30 between 1927 and 1953, when it was renumbered to Route 69 to avoid conflicting with US 30 in southern New Jersey. It was renumbered to Route 31 in 1967 due to sign theft that resulted from the sexual meaning of the number 69. There were plans made in the late 1960s and early 1970s to build a freeway in the Route 31 corridor that would begin in the Trenton area and extend as far north as Interstate 84 (I-84) in Port Jervis, New York; however, it was canceled in the mid-1970s due to opposition from area residents and environmental and financial constraints. In recent years, the portion of Route 31 between Flemington and Clinton has been widened to four lanes. In addition, there was a failed project to build a bypass of Flemington that would have also eliminated the Flemington Circle.