SPRINGFIELD -- A federal study that details the proposed expansion of passenger rail service in the Northeast, with Springfield serving as a key connection, was praised by local advocates Wednesday as a project with great promise and benefits to the region and state.

The three-prong expansion of passenger rail service in the Northeast would serve an estimated 323,000 riders annually in Massachusetts alone, according to the study known as the Northern New England Intercity Rail Initiative (NNEIRI), citing 2035 ridership estimates.

The expansion is both east-west and north-south, also involving Connecticut and Vermont, with a total estimated capital cost of approximately $1.2 billion.

U.S. Rep. Richard E. Neal, D-Springfield, joined by regional and state officials, praised the study results on Wednesday during a press conference at his State Street office in the federal courthouse building.

"It is eminently doable," Neal said. "This is an opportunity not likely to come again."

The report shows "we can do this," Neal said.

U.S. Rep. Richard Neal, D-Springfield, left, and Pioneer Valley Planning Commission Executive Director Timothy Brennan discuss a new federal study that proposes an expansion of passenger rail in the Northeast, with Springfield as a key connecting station.

Timothy Brennan, executive director of the Pioneer Valley Planning Commission, said the project cost is offset by the benefits it will bring, including increased economic development, jobs, access and commuter travel to and from the region, and environmental benefits.

Federal and state funding would be pursued for such an expansion of passenger rail service, Neal said.

The study examined the benefits, opportunities and impacts of adding more frequent and higher-speed intercity passenger rail services along a 470-mile route through New York, New England and the Canadian province of Quebec.

The study recommends the following expansions as being the most cost-effective, and the new services would serve to supplement and expand upon existing services:

New Haven to Montreal -- one daily round-trip with stops at all existing stations between New Haven, Springfield and Montreal.

Boston to Montreal -- one daily round-trip with stops at all existing stations between Boston, Springfield and Montreal.

Boston to New Haven -- eight daily departures with trains stopping at all existing stations along the inland route.

In related news, the Federal Railroad Administration announced a finding on Wednesday that there are no significant environmental impacts that would result from adding more frequent and higher-speed intercity passenger rail service in the Northeast rail corridor.

Under the proposed expansion, the total of 322,650 passengers served in Massachusetts annually would include in this region an estimated 50,000 passengers in Springfield, 16,300 in Holyoke, 12,500 in Northampton and 10,000 in Palmer. It would trigger an estimated 151,300 passengers in Boston and 52,000 in Worcester, among the study results in Massachusetts.

The entire corridor cost is estimated at $1.1 billion to $1.2 billion, including infrastructure and equipment. The infrastructure costs in Massachusetts would total $273 million to $309 million, including: a second track and siding restoration connecting Worcester with Springfield, track improvements, bridge improvements, station infrastructure improvements and signal improvements.

The discussion occurs as the $88.5 million restoration project continues at Springfield's Union Station. The station on Frank B. Murray Street is being renovated as an intermodal bus-rail transit hub.

The study was developed jointly between the Massachusetts Department of Transportation and the Vermont Agency for Transportation, funded by the Federal Railroad Administration.

Those attending the press conference also included Astrid Glynn, rail and transit administrator of the Massachusetts Department of Transportation, who said it fits in with a state study of passenger and freight rail service in Massachusetts.

Neal said the study dates back to 2006, when he and former Congressman John Olver discussed improving passenger rail service in the region. With rail improvements occurring outside the region, the study now reveals a means of "regional equity," Neal said.