NORTH BRUNSWICK, N.J. — All the ingredients for a bustling downtown transit hub here are coming together: new townhouses, restaurants and big-box stores sit just off the busiest rail corridor in the country, as trains whiz by every 10 minutes or so. Bulldozers, backhoes and scattered mounds of dirt offer evidence of more to come. A large banner over a nearby highway with an illustration of a train declares: “Shop. Dine. Ride. Live.”

There is just one piece missing from this rosy picture: any evidence of a train station.

On the longest stretch of passenger rails in New Jersey without a stop, the proposed station would address a glaring need, providing public transit to a bustling area and easing congestion on chronically gridlocked highways. An elevated rail track that is part of the project could funnel more commuter trains to New York City.

But after being unveiled with great fanfare four years ago, the project’s future is unclear. New Jersey Transit, which operates the state’s sprawling rail network, said recently that no funding was available so far for the plan.