Last summer, America's government-subsidized passenger railroad received emergency operating funds, but its long-term future remains in doubt. Critics say rail travel is outmoded and expensive, and that the billions of dollars in subsidies Amtrak receives aren't warranted because it accounts for less than 1 percent of intercity passenger travel. But Amtrak supporters argue that rail travel reduces highway congestion, air pollution and urban sprawl while stimulating economic growth in urban centers. If the railroad received its fair share of federal transportation funding, supporters say, the U.S. would have the finest rail system in the world. Meanwhile, to boost ridership and revenues, Amtrak in 2000 introduced high-speed rail in the busy Northeast Corridor and now is trying to bring HSR to other parts of the country.