Amtrak is asking Congress for $1.53 billion in funding for fiscal 2008, a nearly 18 percent increase from the $1.3 billion Amtrak is getting this year and nearly twice the amount proposed by President Bush.

The national passenger railroad says the increase reflects the need for infrastructure investments, including continued improvements on the heavily traveled northeast corridor.

In the funding request it sent to Congress on Thursday, Amtrak said it had improved efficiency and increased revenues since reform efforts began at the government-owned corporation in 2005. Long-term debt has fallen from nearly $4 billion in 2002 to less than $3.5 billion, it said.

Amtrak's request for operating funding is the same as what it received this year and in 2006 — $485 million. The company characterized that as an improvement, saying it will be able to compensate for inflation by improving efficiency to the tune of $82 million. It said it expected to rely on federal funds to pay 18.5 percent of operating costs, down from more than 20 percent in 2005.

For capital investments, Amtrak is asking for $760 million, up from $675 budgeted this year. That money would go toward an ongoing overhaul of its passenger cars and locomotives and toward improvements to the northeast corridor. Most of the tracks between Washington and Boston are owned by Amtrak, unlike the tracks that most other Amtrak trains run on, which are owned by freight railroads. Amtrak runs its high-speed Acela Express service on the corridor, and commuter railroads also use the tracks.

Bush's 2008 budget would allocate just $500 million for capital expenses and $300 million for operating costs. It includes no separate funds for debt service — a $285 million item in Amtrak's request.

On top of direct Amtrak funding, both plans call for another $100 million to be set aside as matching grants for states to use for intercity passenger rail projects. Such a matching program is also a key element in an Amtrak authorization bill pending in the Senate.

Amtrak President Alexander Kummant has said the railroad should work closely with states to develop service on "corridors" — frequently traveled routes of about 500 miles or less.

Currently, 14 states pay Amtrak for service, but supporters of a matching program say many more would seek expanded rail service if federal support was available.

But counting on states for all of Amtrak's capital needs won't work, even with matching grants, Kummant warned in his funding request.

"While Amtrak believes an increasing share of federal rail funds should go directly to the states on a 'matching' grant basis for use in corridor development, there is a core level of investment in Amtrak that is needed to provide the foundation for growth," he wrote.

Kummant — who was named to the post last year by Amtrak's board, which is made up of Bush appointees — has said it is unrealistic to expect the railroad to ever be completely self-sufficient.