The state is expected to announce plans soon to build the MBTA's Green Line extension through Somerville and West Medford, one of the transit projects legally required as part of the Big Dig, said state and local officials who have been informed about the plan.
The state's plans are also expected to include adding stations on the MBTA's Fairmount commuter rail line in Dorchester, Mattapan, and Hyde Park; doubling the capacity of commuter rail service from Worcester and Framingham to Boston; and increasing parking at some commuter rail hubs, the officials said.
The long-awaited list is to be released in the next few weeks, after a final review by the Romney administration, which is analyzing how much the projects would cost and where to get the money. To move ahead, some of the projects would also need the approval of regional planners and environmental regulators.
The final roster of projects is not expected to include two sought by environmental activists: the restoration of trolley service into Jamaica Plain or building a connection between the Massachusetts Bay Transportation Authority's Red and Blue subway lines, the officials said.
Secretary of Commonwealth Development Douglas I. Foy, who is putting together the project list, said yesterday that it is not completed.
But officials familiar with the projects said Foy has been calling local officials and politicians this week to inform them of the state's plans. Mayor Joseph A. Curtatone of Somerville said Foy contacted him yesterday, but Curtatone would not characterize what Foy told him about the prospects for the Green Line extension.
''I feel confident that at the end of the day this will happen," said Curtatone. ''I'll be doing back flips when it does. But we're not there yet."
He and others in Somerville have been pushing for years for the extension, which is projected to draw between 10,000 and 14,000 additional boardings a day. The Green Line now has about 225,000 boardings a day.
In 1990, the state promised to expand and modernize the Boston area's transit system to offset the pollution caused by the Big Dig and the congestion resulting from its construction.
That agreement called for the Green Line extension, the connector between the Red and Blue Lines, the Arborway trolley through Jamaica Plain, and several other projects. Some, including the Silver Line bus service and the Greenbush commuter rail line, are under construction.
In March, the Conservation Law Foundation, which Foy once headed, sued the state, contending that it had failed to keep all its commitments.
The state would be reneging on its initial pledges if it does not include the connector between the Red and Blue subway lines (projected to cost between $174 million and $220 million) or the Arborway trolley project in Jamaica Plain (estimated at $77 million), Philip Warburg, president of the law foundation, said yesterday. Because of that, he said the foundation's lawsuit against the state would probably continue, even if the state moves forward with the Green Line extension and other projects.
''If key elements in those commitments . . . are now being taken off the table, we feel that this is sad confirmation that the state can't be trusted to keep its promises," Warburg said.
Kevin F. Moloney, a lawyer and member of the Arborway Committee, said yesterday, ''If it's true, it would be confirmation of the cynical and deceitful activities of the various state officials involved."
As part of a $31 billion, 20-year transportation plan unveiled in March, Romney announced that the state would begin paying for MBTA expansion projects, including the Green Line extension. Many of the Big Dig transit projects would also be eligible for federal funding.
The Green Line now stretches from Boston's western suburbs to East Cambridge. The different routes being examined to extend it into Somerville and Medford range in price from $340 million to $438 million. The final route and station locations are being studied. Curtatone and others have insisted that the extension needs to stop in Somerville's Union Square.
Recent projections on ridership and air quality for the Green Line extension were better than expected, according to members of an MBTA advisory committee.
T officials told the group last week that the numbers will allow the project to begin a federal environmental review, the last step before the state can seek federal money to help pay for the project.
State Senator Jarrett T. Barrios, who represents Somerville, said he speaks regularly with Foy about the Green Line extension.
''This is the best transit project on the drawing board in Massachusetts and will serve the densest community currently underserved by mass transit," Barrios said.
Improving the MBTA's Fairmount Line will cost the state about $43.5 million, money already earmarked in the state transportation bond bill. Expanding parking lots around commuter rail hubs will require construction funds and the purchase of millions of dollars of nearby land.
Doubling the number of passengers that the Worcester-Framingham commuter rail line can carry could require purchase of miles of rail from freight carrier CSX, according to state officials. A less expensive option would be a stronger lease giving greater access to the CSX tracks, officials said.
The project jibes with recent promises from the Romney administration to boost Worcester's City Square redevelopment project, which includes 900 units of affordable housing and is connected to the city's downtown train station.
The Red Line-Blue Line connector also has its supporters. Former state transportation secretary Fred Salvucci said it is the only Big Dig transit project that has operating funds set aside.
''The best buy for the money in terms of improving the use of public transportation is the Blue to Red connector," he said. ''A lot of the other projects are very good; the T is going to have to develop new sources of operating money to pay for them."
US Representative Michael E. Capuano, a Somerville Democrat and former mayor, said that while the Green Line extension has ''been a long time coming," he hopes that the projects expected to be left off the to-do list won't be forgotten.
''I'm just hoping those decisions were made on the basis of facts and not on the basis of politics," he said.
Mac Daniel can be reached at email@example.com.