Amtrak's updated plan for high-speed train travel on the East Coast envisions 37-minute trips between Philadelphia and New York, after a $151 billion redevelopment of the entire Northeast Corridor.

Faster service would be phased in gradually, as Amtrak improves existing tracks, signals, bridges, and power lines and then builds a separate high-speed corridor between Washington and Boston to accommodate trains traveling at 220 m.p.h.

In a report released Monday, Amtrak revised its projections for costs, ridership, and the alignment of its proposed new 438-mile high-speed corridor. The high-speed segment between New York and Washington would be completed by about 2030, and the route between New York and Boston by 2040, according to the plan.

In Philadelphia, Amtrak envisions bullet trains traveling in tunnels beneath the city, with stops at a new airport station and an expanded Market East station. The plan calls for 30th Street Station, now the city's main intercity rail hub, to be used for slower regional train service.

The current corridor between Washington and Boston is old and crowded, with highways, airports, and railroads that are unable to handle growing population and demand, Amtrak president Joseph Boardman said. Without ambitious rail expansion, the region's economy will be stifled, he said.

"I think what's at stake here is the global economic engine of the Northeast," Boardman said in an interview. "The business community in the Northeast has to wake up - they're at risk."

Amtrak says the costs of building the new rail system would be offset by 40,000 construction jobs a year for 25 years, 22,000 new permanent jobs, and increased revenue and productivity for East Coast employers.

Amtrak's new report comes as 1,000 international high-speed rail operators and manufacturers convene this week in Philadelphia for the eighth World Congress on High-Speed Rail. It's the first time the biennial session has been held in the United States, which lags Europe and Asia in rail development.

"We are inheriting the lessons learned from nearly 50 years of development of this technology," said Stephen Gardner, Amtrak's vice president of Northeast Corridor infrastructure and investment development. "Everything is on our side. I know it has looked bleak at times, with the constrained economic period we're in, but time is on our side."

The new Amtrak report proposes a series of steps on the way to true high-speed rail service with 220 m.p.h. trains by 2030:

By 2015, Amtrak will acquire 40 more Acela Express passenger cars to increase capacity by 40 percent on the fastest trains now operated by Amtrak. (Acela trains can reach 150 m.p.h. on a stretch of track between Boston and New York, but the trains average just 84 m.p.h.)

By 2020, Amtrak plans to double Acela service between New York and Washington, with upgraded tracks and signals allowing train speeds of 160 m.p.h. and reducing Acela travel time between New York and Philadelphia to 62 minutes, from the current 70 minutes.

By 2025, Amtrak proposes to complete the $14.7 billion "Gateway" project to improve access to New York, with two new tunnels under the Hudson River, an expanded Penn Station, and two new high-level bridges to replace the 100-year-old movable Portal Bridge over the Hackensack River.

By 2030, Amtrak says, the high-speed corridor would be complete between New York and Washington, with trains making the trip from Philadelphia to Washington in 54 minutes. (By comparison, the fastest Acela trip now takes 93 minutes.)

By 2040, Amtrak proposes to have the full high-speed corridor complete, with trains running between New York and Boston or Washington in 94 minutes. A trip from Philadelphia to New York would take 37 minutes, about half the time of the fastest train today.

Money remains a problem for Amtrak as it looks to a faster future.

Congress has rejected the Obama administration's request for $50 billion for high-speed rail over six years, and Amtrak is dependent on annual appropriations from Congress for its survival.

Amtrak reduced cost estimates in its new plan by combining proposals for upgrading the existing corridor and building the high-speed line.

Now, Amtrak calls for spending $3 billion to $4 billion a year during peak construction years and delaying some spending beyond 2040, when ticket revenues of $4.86 billion a year are anticipated to be rolling in from 43.5 million passengers.

If federal, state, and local governments pay to build the new high-speed rail system, Amtrak says, the revenues from the trains will more than pay for the costs of operating and maintaining them. Amtrak projects a $928 million operating surplus by 2040, which could be used to pay back money borrowed for construction.

"It's clear to me that it will take every level of the public sector and new involvement by the private sector to do this," Gardner said. "The federal piece is the linchpin."

He predicted the federal government would need to pay about half of the $151 billion cost of building the system, with state and local funds, tax credits, and long-term borrowing making up much of the remainder.

"There is no mechanism at the federal level to support this today," Gardner acknowledged.

Amtrak is waiting for the Federal Railroad Administration to complete a required environmental-impact assessment of the corridor to come up with a "preferred alternative" for development. That assessment is expected to take until June 2015.

In the meantime, Amtrak is moving to build political and popular support for funding and building its proposed high-speed corridor.

With incremental projects now under way, like a $450 million effort to increase train speeds between Trenton and New Brunswick, Amtrak hopes to demonstrate its ability to get bigger and faster.

"We want to build a railroad that can significantly increase its service levels and do much more for the region," Gardner said. "We think rail needs to move a lot more people in this corridor, and we need to build capacity to do that."