Shortly after the Massachusetts Department of Transportation allocated $123 million for passenger rail service between Boston and the western part of the state, longtime proponent U.S. Rep. Richard Neal said the “reality of west-east rail is happening right before our eyes.”

The funding, most of which was announced last fall but is now officially earmarked, comes from the federal government and is included in MassDOT’s $16.7 billion five-year capital improvement plan approved last week.

The west-east rail will connect the eastern and western sides of the state by expanding service from Boston to Springfield, at which point the route will split between New Haven, Connecticut, and Albany, New York. The first phase of the project, expected to be completed by 2029, will focus on the inland routes from Boston to New Haven. The second phase will expand service from Boston to Albany.

“West-east rail is a significant undertaking, but not to miss the point that we have made great strides in recent years,” Neal said in a statement.

Among the accomplishments are the reopening of Springfield Union Station in 2017 and the $108 million Consolidated Rail Infrastructure and Safety Improvements grant announced last fall.

That $108 million is included in the $123 million allocated in the five-year capital plan, according to Trains in the Valley co-founder Ben Heckscher. The money is for adding and expanding tracks between Worcester and Springfield, allowing trains to travel up to 80 mph.

Of the remaining money, MassDOT reports that $7.5 million will fund track improvements at the Pittsfield station, $3.5 million will help design and plan the Palmer station, and $2.2 million will support preliminary engineering and environmental preparations for reconfigurations of tracks in the Springfield area.

“Its officially in the capital plan, but it doesn’t really change anything,” Heckscher said, adding that planning and track expansion are already moving forward. He predicts construction will begin in roughly two to three years.

The west-east rail project has been in development since 2022, although efforts to study the corridor and expand rail from the eastern side to the western side of the state began back in 2013. The East-West Passenger Rail Study from 2021 estimated the project would cost between $2.6 billion and $4.6 billion. So far, the state has secured $424.75 million in federal grants for the project.

In June, Gov. Maura Healey’s administration allotted $3 million for the Inland Route and $1.75 million for preliminary engineering and environmental work for track, signal and infrastructure improvements near Springfield’s Union Station. The funds were part of a $13 million package for local transportation projects eligible for federal discretionary grants.

Currently, most of the passenger rail between Springfield and Worcester rides on a single track that’s shared with freight trains, so passenger trains often need to pull off and wait for a freight train to pass before continuing on the route. Track improvements and expansions will allow more trains to run simultaneously, eliminating this problem and creating opportunities for more trips.

“It’s like putting building blocks together,” Heckscher said. “You can add on top of that because once you have additional tracks you can run additional trains.”

Palmer residents long campaigned for a station in their town for developmental and economic interests as written on the Trains in the Valley website. The funds allocated in the five-year capital improvement plan will allow the long-awaited project to move from the idea phase into the planning phase.

“There’s planning work going on to figure out where the station should be located and conceptually what it should look like so they can apply for grants to build it,” Heckscher said. “These things are incredibly complicated to do and it just takes time for all the planning and design work that needs to be done.”

Heckscher added that, while expansions of track in Connecticut and the redevelopment of the Springfield station are not technically part of the west-east rail project, these types of improvements indirectly support the expanded service. The Worcester station, for instance, recently added a second platform to allow two trains to stop at the station as part of a different MBTA (Massachusetts Bay Transportation Authority) project, but the expanded capacity supports trains moving along the west-east rail.

“It’s great that it’s moving forward. I’ve been working as an advocate for about eight years, and we have had ups and downs along the way with different governors,” Heckscher said. “Clearly now we have money and political will, and when you have money and political will, you can make big projects happen.”

Emilee Klein can be reached at eklein@gazettenet.com.