WASHINGTON — Gov. David A. Paterson on Tuesday unveiled the stateGs application for federal highspeed rail funding, and its price tag — $11.6 billion, or $4 billion more than an earlier estimate — left even the planGs supporters gasping.

"Soft costs" such as engineering and design work, which were not included in the earlier $7.6 billion estimate, and inflation account for the increase in the cost of the plan to link Buffalo and the stateGs other major cities with high-speed rail, said Skip Carrier, a spokesman for the state Department of Transportation.

The application detailed $58 million in requested funding for rail improvements between Buffalo and Niagara Falls, but that paled in comparison to the $5.5 billion request for improvements between Albany and Buffalo and the $11.6 billion total.

Asked about the $4 billion increase, Carrier said: "It was not a binding $7.6 billion."

But it was a confounding $11.6 billion, given that only $8 billion in federal high-speed rail funding is currently available under the federal stimulus bill and that 24 states are seeking that money.

President Obama is asking for an additional $1 billion in federal highspeed rail funding for each of the next five years, and state officials designed their bid with that additional funding in mind.

Nevertheless, the size of the stateGs request surprised even Bruce Becker, president of the Empire State Passenger Association.

"It certainly causes me to want to know how they came up with that number," Becker said.

The stateGs application fleshes out some new elements of the plan to extend high-speed rail lines across the state.

The federal money aims to boost the speed of the passenger rail service from Albany to Buffalo and back to 110 mph.

The state is asking for $5.5 billion in federal funding just for that Albany-to-Buffalo stretch of the high-speed system, with other improvements aimed at other parts of the state.

Technical limitations would keep trains traveling at less than 60 mph between Buffalo and Niagara Falls. However, the state is also seeking about $58 million to improve infrastructure in Niagara Falls and on the train line connecting it to Buffalo, since many of the trains would continue on to Niagara Falls, albeit at a lower speed.

"Improvements and investments in rail lines between Buffalo and the Falls, in addition to improvements to the rail station, will allow Niagara Falls to become a stronger center for international trade and will be one more way for tourists to reach the majestic falls," said Rep. Louise M. Slaughter, DFairport, a leading proponent of high-speed rail.

The stateGs application is still lacking some important details. For example, the part of the application aimed at spelling out how many passengers would use the faster trains is answered as "TBD" — or "to be determined."

The projectGs permanent job-creation prospects are listed as "TBD," as well.

"The lack of detail certainly leaves open a lot of questions," Becker said. "ItGs a work in progress still, no doubt about it."

Still, Paterson praised the planGs potential.

"This funding will support a vigorous program of high-speed rail improvements that will promote economic development and job creation throughout upstate New York, as well as energy and environmental benefits in the years ahead," Paterson said.

The stateGs application is one of 45 that the Federal Railroad Administration has received from 24 states. While the stimulus funding for high-speed rail totals only $8 billion, the funding requests total approximately $50 billion.

In addition, the rail agency received 214 applications from 34 states for rail planning and other smaller projects. Those requests totaled $7 billion.

The volume of applications has prompted the agency to delay announcing the funding winners from the fall to sometime this winter, said Federal Railroad Administrator Joseph F. Szabo.

"Our selections will be merit- based and will reflect President ObamaGs vision to remake AmericaGs transportation landscape," Szabo said.