The case for investment in the passenger rail network known as the Northeast Corridor is, on the face of it, easy to make. The 457-mile route from Washington to Boston is the busiest rail system in the country. It connects four of the nation’s 10 largest metropolitan areas, and the region it serves accounts for about a fifth of the U.S. economy.

For years, transportation officials haven’t been able to find enough money to keep the system working at basic levels, never mind make it better. The Federal Railroad Administration estimates the crowded corridor needs about $20 billion to keep it running as it does now — nobody’s idea of good.

Even if the money can be found, one of the rail network’s biggest problems is the multitude of governments, agencies, communities and transportation providers that have to cooperate to plan and carry out projects.

Eight commuter lines and four freight railroads use part of the infrastructure. Amtrak, a government-subsidized corporation that loses money and relies on Congress for funds, owns 363 miles of the route — most of the rail spine. Segments are also owned by public agencies in Connecticut, Massachusetts and New York.

“I think the reason you end up with jurisdictional arguments is because the issue is so difficult and the cost is so dramatic,” FRA Administrator Sarah Feinberg tells CQ Roll Call. “I mean, if this were an easy thing to do there would be no jurisdictional arguments and there wouldn’t be any arguments about cost.”

The announcement last month of a state-federal agreement for building a new rail tunnel connecting New Jersey and New York under the Hudson River — one of the biggest capital investments needed on the corridor — raised hopes that political barriers to consensus can be overcome to get improvements started.

In a sit-down with CQ Roll Call, Amtrak President and Chief Executive Joseph H. Boardman decried the fact that movement on the tunnel project only came in response to a growing crisis.

“What drove this and really made it happen was the failure of the infrastructure,” Boardman says, recounting the reaction after delays over the summer created headaches for commuters. “That seems to be the way Congress and governors and others are approaching the need to improve our infrastructure, and it’s wrong.”

Congress has been tight with funds, but it has nevertheless created a policy framework for better decision-making. In 2008, it established the Northeast Corridor Infrastructure and Operations Advisory Commission to get the ball rolling on system improvements.

The FRA has added momentum with NEC Future, a planning initiative that released environmental documents for proposed projects in November that are open for public comment until the end of January.

James Redeker, the advisory commission chairman, says the panel’s primary responsibility was to allocate costs among users of the infrastructure. Redeker says the commission has agreed on a plan for reallocating about $200 million in annual costs based on use in each jurisdiction, but the problem will be getting governments and agencies to go along. “No one understood how hard this would be,” says Redeker, who is also Connecticut’s transportation commissioner.

The FRA, in its documents released in November, laid out three investment alternatives for improvement over the next 25 years. The cheapest is $65 billion; the most expensive would cost almost $300 billion. The cost of merely maintaining the current system? $20 billion.

So who will pay the freight?

“Well, it’s a little early to determine how much of this the federal government can take on compared to how much the states or even the private sector will end up taking on. And it may be different for different projects,” Feinberg says.

Once a path forward is chosen and governments begin gearing up with funding for such plans, Feinberg adds, “then I think we have to start looking at how we can split up resources and split up investments. But it’s too early to say.”

The FRA’s alternatives are in part about giving the network redundancy, the ability to continue to run trains even when a track or tunnel is out of service. But there are many segments of the corridor where the infrastructure is just plain inadequate.

The curves in tunnels in Baltimore force trains to cut speeds in half, to 30 miles per hour. The Bush River Bridge in Maryland needs 20 workers to open it for passing boats. Problems closing it in a 2012 incident delayed Amtrak trains for 10 hours. Corrosion on the Connecticut River Bridge in Connecticut keeps train speeds at 45 miles per hour.

Those kinds of delays can be felt from Washington to Boston. Big investments in one area may still leave the whole network vulnerable to bottlenecks elsewhere.

The NEC, FRA and Amtrak investment plans are in many cases about removing those problems: two more Hudson River tunnels, higher bridges, modern mechanisms for opening and closing bridges.

Whatever the investment option chosen, the federal role will be a big one.

Democratic Sens. Charles E. Schumer of New York and Cory Booker of New Jersey said last month the federal government and Amtrak had agreed to pay for half of the Hudson River tunnel project. But they didn’t say half of how much.

CQ asked Transportation Secretary Anthony Foxx about it later in November.

“I think notionally, a 50 percent federal contribution isn’t a crazy idea, but we’ve got a lot of steps we have to go through before we can achieve it,” Foxx says.

Congress has been inventive in recent years about getting money to passenger rail. In addition to Amtrak grants and a variety of rail programs, the 2009 economic stimulus and Superstorm Sandy relief legislation in 2013 steered money to the busy corridor.

Adie Tomer, a fellow with the Brookings Institution, says Congress has shown a willingness to make investments, but it needs to decide priorities for the region and invest accordingly. “This place just really matters,” he says. “It’s not that other places don’t. It’s just that this one unquestionably does. And there’s national importance to have the financial market and the national capital be accessible.”

Foxx says Congress faces a big task. “There’s a massive amount of work that Sen. Schumer and Sen. Booker and others will have to do to encourage their colleagues on the Hill to appropriate resources to help move this along,” he says. “We’re not there yet, but I think that’s something that will be in the offing at some point in the future.”

The FRA report laying out three alternatives to improve the corridor says the area that would benefit reaches deep into Virginia, goes north of Albany, N.Y., and stretches into New Hampshire. On that basis, the corridor touches 77 House districts, including those of four Republicans on the Transportation panel.

Rep. Ryan A. Costello, R-Pa., is one of them.

“If things get parochial, it won’t work,” Costello says. “States and regional transit authorities are going to have to look at it and say, what’s our appetite, what’s our need, and what do our constituents feel? Until this penetrates other government constituencies, it’s too early to offer what’s preferred.”