The Hudson River needs a new rail tunnel. Hurricane Sandy flooded and seriously damaged the existing tracks, which means that the 400,000 commuters who rely on taking NJ Transit and Amtrak into the city every day have had to confront frequent delays while waiting for governors Cuomo and Christie (who rarely take public transportation themselves, and still manage to screw up when they do) to stop quibbling over who should pay for a new and improved tunnel. Last fall, the governors finally agreed to go splitsies with the federal government on the cost of a new tunnel, and not long after, the feds agreed to fund half of the $24 billion dollar Gateway Tunnel. But the project requires a lengthy review process, and the longer that takes, the more the project will cost, a new report says.

The Gateway project will construct a new, high-speed rail tunnel under the Hudson, and theoretically double the number of trains running under the river. Both Amtrak and the Port Authority recently agreed to put $35 million each toward the project, adding to Cuomo and Christie's commitments of $5 billion each and the federal government's pledge to cover the rest. It's taken a while just to get all parties to agree to this much—but unless the environmental review and permitting process is expedited, those costs will surely skyrocket, according to new analysis from Common Good, a nonpartisan reform coalition.

A three-year review and permitting process would increase costs by over $3 billion, Common Good said this week, and if that was delayed by another two years, costs would rise to almost $10 billion. And that's not even taking into consideration the fact that there's a good chance the existing tunnel could become unusable and have to shut down before construction on the Gateway Tunnel is complete—Amtrak has said that the tunnel could fail at any point in the next 19 years. Delays of any amount will continue to increase construction costs and contribute to lost business activity and lost property tax revenue on both sides of the Hudson, this report says.

The report notes that there's not currently a clear timetable for the review and permitting process, nor an agreement on the scope of the environmental review. A similar plan for a new Hudson River tunnel was cancelled in 2010 by a grossly cost-exaggerating Christie, but prior to its cancellation, that project underwent a six-year environmental review and permitting process.

Amtrak has estimated that this review will take three years, while other officials interviewed by Common Good have estimated it taking twice that long. If the review takes five years, the Gateway Tunnel wouldn't open until 2028 at the earliest. Earlier this week, Amtrak, NJ Transit, and Federal Transit Administration officials said that they're committed to a two-year schedule, but Philip Howard, the author of Common Good's report, said that a federal official should be tasked with overseeing the process and ensuring that it takes no more than a year.

There will be a public meeting later this May in New Jersey about the Gateway Tunnel project—that is, if you can squeeze it in alongside all the other meetings we've been invited to lately about Sandy-necessitated construction. But if you are able to attend, it's on May 19th from 3 p.m. to 8 p.m., at 2500 Kennedy Boulevard in Union City.