Federal rail regulators are endorsing an ambitious and costly plan to rebuild the congested Northeast Corridor over the next 30 years that they say will shore up crumbling infrastructure, increase service and speed up travel, with some trains eventually able to reach 220 mph on a stretch of the Washington-Boston route.

The Federal Railroad Administration's plan unveiled Friday aims to cut down on delay-causing bottlenecks and increase capacity by upgrading outdated bridges and tunnels, including ones into New York City that are more than a century old, and realigning tracks to eliminate speed-restricting curves.

The agency estimates the changes will cut travel times between Washington and New York by 35 minutes, to about 2 hours and 10 minutes on the fastest trains, and save 45 minutes to an hour on trips between Boston and New York, which now take close to 4 hours.

The $120 billion plan is the product of a four-year process that sought input from state and local governments, residents, Amtrak and eight commuter railroads. About 750,000 people travel on the Northeast Corridor each day. Now it's up to the states, railroads and President-elect Donald Trump to figure out if they're on board.

Amtrak's Stephen Gardner said the plan, the first comprehensive look at the future of the rail network, affirms the railroad's "long-held view that rebuilding and expanding the Northeast Corridor is essential for the growth and prosperity of the entire region."

Among the other provisions in the plan: an Amtrak stop at Philadelphia's airport, eliminating the need for some travelers to reach the city and switch to a commuter train; increased service to parts of Connecticut, Rhode Island and Massachusetts; and add a new level of service that makes stops at a variety of commuter rail stations and major city hubs.

New Jersey Democratic Sen. Cory Booker, who's been involved in the planning and the $20 billion-plus Hudson River rail tunnel project, applauded the FRA's plan.

"They recognize that the Northeast Corridor is not adequate for today and is not an adequate transportation pathway for tomorrow," Booker said. "The fact that we're choking growth and productivity is unacceptable."

According to federal data, the Northeast is responsible for about 30 percent of jobs in the U.S. and 20 percent of the nation's gross domestic product. By 2040, federal estimates show, the region's population is expected to grow by about 7 million people.