Route 129 is a major arterial boulevard state highway in the capital city of Trenton, New Jersey. The highway runs along Canal Boulevard, a four-lane arterial through portions of Trenton, serving as an alternative highway to its parent, Route 29. The route begins at an intersection with Lamberton Road in Hamilton Township, heads northward along the River Line maintained by New Jersey Transit until terminating at an interchange with U.S. Route 1 (the Trenton Freeway).