Gov. Chris Christie and New York Gov. Andrew Cuomo have agreed on a plan that could lead to funding for a proposed Gateway trans-Hudson rail tunnel.

A morning northbound Amtrak train approaches 30th Street Station in Philadelphia (Mark Makela/Getty Images)

When asked recently about funding for the planned rail tunnel, Cuomo unenthusiastically said it wasn’t his tunnel.

It seems he’s changed his tune, because Tuesday, Cuomo and Christie fired off a joint letter to President Barack Obama with a detailed funding plan that called for the federal government to pick up 50 percent of the cost. They urged the president to quickly review and approve the concept.

“We are writing jointly in an attempt to move the stalled project forward by putting a funding proposal on the table that we believe is realistic, appropriate and fair: split the responsibility for the cost. If the federal government will provide grants to pay for half of the cost of the project, the Port Authority, New York and New Jersey will take responsibility for developing a funding plan for the other half, convening all relevant agencies, and utilizing the proposed federal low-interest loan, local funding sources, and other funding strategies necessary to complement the federal grant commitment,” the governors wrote.

Leaders in New Jersey responded quickly to the letter. They were generally positive, but also cautious. They said that under no circumstances can the Garden State be forced to foot more of the bill than our neighbors across the Hudson River.

“The Port Authority could step in and take that position for both states,” said State Sen. President Steve Sweeney (D-Thorofare). “It’s important that the two governors are willing to step up and move the project forward. It’s really a win for the people of New Jersey and New York.”

The availability of a low-interest, long-term $30 billion loan program should make it easier for the two states to share the expenses equally Sweeney explained and he vowed that the NJ Legislature is ready to help in any way possible to get the Gateway project going.

Christie and Cuomo's decision to send a joint letter was cause for Senate Majority Leader Loretta Weinberg to be optimistic that a final funding plan would be equitable. She thought the federal government should pay the lion’s share of the cost.

“Yes, this is a big deal. It’s a big step forward. This is a regional project of import to the entire United State,” said Weinberg (D-Teaneck).

The head of the New Jersey Department of Transportation released a written statement applauding Christie and Cuomo and talking about the importance of the Gateway project to the entire Northeast region.

“The need for this new tunnel cannot be overstated. It is absolutely essential for the region and the residents of both New Jersey and New York. This letter represents progress and a sends a bipartisan message that the time is now. We cannot wait for our century old system to fail us,” wrote NJDOT commissioner Jamie Fox said in a press release.

Transportation experts also responded favorably including Veronica Vanterpool, executive director of the Tri-State Transportation Campaign.

“Without this project, our $3 trillion regional economy will suffer, traffic congestion and safety will get worse and environmental gains from the region’s high transit ridership will be lost. The funding framework put forth, that the federal government pay for half of the project while New York, New Jersey and the Port Authority of New York & New Jersey develop a financing plan for the other half, makes sense,” Vanterpool said in a press release.

The tunnels liking New Jersey and New York are 105-years-old and many are worried about what would happen if they have to be shut down due to deterioration.