The changes would allow Acela Express trains to go as fast as 160 m.p.h. on that stretch, up from the current top speed of 135. That would surpass the 150 m.p.h. top speed that Acela trains now reach on a small section of the corridor between New York and Boston.
It would shave about 10 minutes off the current 65-minute fastest Acela trip between New York and Philadelphia.
The $450 million project, which will also improve reliability for non-Acela trains and reconfigure track switches at the western entrance to New York's Penn Station to ease congestion there, is slated to be completed by September 2017, Amtrak said.
Amtrak applied for $1.3 billion of the spurned Florida high-speed rail money. It did not get funding sought for several key elements of its proposed "Gateway Project" to increase capacity and reliability into New York City, including a new bridge to replace the century-old Portal Bridge across the Hackensack River.
With its Gateway Project, Amtrak this year took the lead in planning for new tunnels and bridgework into New York City after Gov. Christie withdrew New Jersey's support and funding for new tunnels under the Hudson.
Although the money awarded Monday is not part of the proposed Gateway project, it "most definitely supports Gateway," said Amtrak spokesman Steve Kulm.
The other Northeast Corridor awards:
Maryland - $22 million for engineering and environmental work in preparation for the replacement of a century-old bridge over the Susquehanna River.
New York - $295 million for a bypass around a busy choke-point in Queens for trains approaching and departing Manhattan.
Rhode Island - $28 million for a third track near Kingston to allow high-speed trains to pass slower ones, and for preliminary work on renovations of the Providence station.
In addition, Pennsylvania will get $40 million to rebuild a rail intersection near Harrisburg on the Keystone Corridor to improve reliability on the Philadelphia-Harrisburg route that now carries 1.3 million riders a year.
In other regions of the country, $404 million will go to expand higher-speed rail service in the Midwest, $340 million will go for new locomotives and rail cars for California and the Midwest, and California will get $300 million for a 20-mile section of the route designed to eventually carry 220-m.p.h. trains between San Francisco and Los Angeles.
The $2 billion awarded Monday had been given last year to Florida for high-speed trains between Tampa and Orlando. After Republican Gov. Rick Scott canceled the project this year, the Transportation Department invited other states to bid for the funds. It received 90 applications seeking a total of $10 billion.
Scott said he was concerned that Florida would be locked into years of operating subsidies. However, a report by the state's transportation department forecast the rail line would be profitable.
Two other Republican governors elected in November also have canceled high-speed train projects in their states. Wisconsin Gov. Scott Walker turned down $810 million to build a Madison-to-Milwaukee high-speed line. Ohio Gov. John Kasich rejected $400 million for a project to connect Cincinnati, Cleveland, and Columbus.
Both the Ohio and Wisconsin projects had been approved by the governors' Democratic predecessors.
Contact staff writer Paul Nussbaum at 215-854-4587 or firstname.lastname@example.org