The Federal Transit Administration is awaiting an updated financial plan from the city as Honolulu’s $5.5 billion rail transit project moves forward.

The last financial plan, prepared in 2009 by Parsons Brinckerhoff, presented "very little capacity to absorb cost increases or funding shortfalls and has potentially significant revenues risks," according to the FTA’s fiscal 2011 transit project financial assessment.

But FTA Administrator Peter Rogoff said yesterday that financial plan "matters less than the new financial plan" expected in spring.

"Sometimes you need to be mindful of this: These financial projections are just that, projections," Rogoff said in a conference call with reporters. "They change as interest rates change … as local revenue estimates change. The most updated plan is always the most important one."

On Monday, President Barack Obama presented his fiscal 2012 proposed budget, which included $3.2 billion for locally funded transit guideways. Obama budgeted $250 million for the city’s rail transit project out of the $1.55 billion total sought by the city.

Rogoff said the FTA needs to see a financial plan that demonstrates the city can meet its financial obligations and that its existing bus service continues to operated and be maintained.

Mayor Peter Carlisle said the city won’t disturb funding for TheBus.

"TheBus is a critical and essential part of our infrastructure, and it cannot in any shape, fashion or form be compromised and we’re going to stick to that," Carlisle said.

An updated financial plan will be completed by "late spring or early summer," the mayor said.

Parsons Brinckerhoff is also preparing the updated plan. It will have information on collections thus far on the general excise tax surcharge of 0.5 percent for rail, and what has been spent.

"The further we move forward, the more exact information we’re going to have," Carlisle said.

Carlisle said the city’s goal is to negotiate its next contracts under what the original expectations were, just as it did with Kiewit Pacific Co., which won a $483 million contract to build the first phase of the project.

Two more contracts are in the works: one for the second phase of the route, which runs from Pearl City to Aloha Stadium, and another for a core systems contractor to supply train vehicles and manage the control center.

"We’re hopeful that doing it now and tying them in at today’s prices is a good idea," Carlisle said. "The more we can do now, the more we can tie down where we’re going in the future, the better we’re going to be."

There are still questions about whether Congress, with a Republican-controlled House, will approve full funding for rail. Rogoff said yesterday he had not spoken with U.S. Rep. John Mica, R-Fla., about Honolulu’s project. Mica has said in a statement through the mayor’s office that he supports the project.

Rogoff said the FTA would not have put any project in the proposed budget if officials "didn’t feel like we would get to the finish line."

"We’re very optimistic about this project, and it’s going to serve a very critical need," he said.