The planning effort would be "one of the most comprehensive and inclusive transportation plans ever attempted on a broad, regionwide basis," the coalition wrote in a proposal submitted to the FRA.

The Northeast Corridor describes the nation's busiest passenger and freight rail network from Boston to Washington, D.C.

Amtrak has estimated that passenger rail ridership along the corridor could double to 28 million by 2030, with a four-fold increase to 60 million riders possible by 2050. Much of the growth was expected to occur in the region's smaller and medium-sized cities.

The 11 states -- Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont -- are proposing a three-year, $18.8 million study of possible enhancements to both intercity rail service, such as Amtrak's Acela Express, and local commuter rail systems that use portions of the Northeast Corridor track.

The proposal calls for the federal government to provide $15 million for the study, with the rest coming from the states.

No cost estimate was given for any of the improvements that might emerge from the study, but the states acknowledged funding limitations and recommended that railroads and other agencies that would benefit from the upgrades contribute to the eventual cost.

Amtrak supported the proposed study.

"We look forward to continuing with our regional wide partnership as we move forward with the goal of developing the next-generation Northeast Corridor, including expansion of high-speed rail services," Joseph Boardman, Amtrak's president and chief executive, said in a statement.

The coalition said the FRA should identify both short-term and long-term projects that were outlined in a recent Northeast Corridor Infrastructure Master Plan. They included an expansion of rail service to smaller cities, including Hartford, Conn., and outlying areas, such as the Pocono Mountains of Pennsylvania, as well as improving Acela travel times by 20-30 minutes between Washington and New York City and between New York City and Boston.

The states noted that while the corridor encompasses an area that makes up only 2 percent of the U.S. land mass, it's home to about 20 percent of the nation's population and generates 20 percent of its gross domestic product.

Highways and airports in the Northeast already face "major congestion and capacity constraints," and the coalition warned that failure to enhance rail service would severely limit the travel needs of the region's 62 million residents and hurt economic growth.