Route 12 is a state highway located in Hunterdon County, New Jersey, United States. It runs from the Uhlerstown–Frenchtown Bridge at the Delaware River border with Pennsylvania in Frenchtown east to an intersection with U.S. Route 202 (US 202) and Route 31 at the Flemington Circle in Flemington. The route is mostly a two-lane undivided road that passes through rural areas of woodland and farmland. It intersects Route 29 and County Route 513 (CR 513) in Frenchtown, CR 519 in Kingwood Township, CR 579 on the border of Delaware Township and Raritan Township, and CR 523 in Raritan Township.
The route was designated in 1927 to run from Frenchtown to Raritan, Somerset County, running along its current alignment to Flemington and following present-day US 202 between Flemington and Raritan. By the 1940s, US 202 and Route 29 replaced Route 12 east of Flemington, and the route was officially designated to end in Flemington in 1953. There are currently plans to modify or eliminate three traffic circles along the route in Flemington to ease traffic congestion.
Route description
thumb|left|County-maintained portion of Route 12 in Frenchtown signed as CR 610
Route 12 begins at the Uhlerstown–Frenchtown Bridge over the Delaware River in Frenchtown at the Pennsylvania / New Jersey border, where it connects to Pennsylvania Route 32. The bridge and short portion of its eastern approach is maintained by the Delaware River Joint Toll Bridge Commission. two-lane undivided Bridge Street. By the 1940s, US 202 and Route 29 were designated along the alignment of Route 12 between Flemington and Raritan, cutting the route's eastern terminus back to Flemington. In the 1953 New Jersey state highway renumbering, Route 12 was officially legislated to run from Frenchtown to US 202 and Route 69 (now Route 31) in Flemington. There are currently plans to modify or eliminate the three traffic circles along Route 12 in Flemington in order to ease traffic congestion along the route. The Main Street Circle was converted to a modern roundabout in 2010 while plans are still being thought out for the other two traffic circles.
By Joint Resolution No. 1, approved April 22, 1940, the New Jersey Legislature designated Route 12 from the junction with present-day Route 31 to Croton as the Samuel Hill Highway, in memory of local industrial pioneer Samuel Hill.