For years, it seemed like the only news about the Green Line extension was that it wasn’t happening — ballooning costs, more and more distant opening dates, delays, and disappointment.
But now, more than three decades after the state first promised to extend the Green Line as environmental mitigation for the Big Dig, test trains are gliding along the tracks between North Station and Union Square ahead of a planned opening of the project’s first branch next month.
And the T is on the precipice of finally offering passenger service on an extended Green Line.
“We’ll be ready for service in March,” MBTA general manager Steve Poftak said Wednesday as he rode on a test train with media members.
As the trains make their way past a new Lechmere station in Cambridge toward Somerville, they travel on a brand new viaduct. A new railyard for storing and maintaining Green Line trolleys can be seen out the right side windows. The new Union Square station is surrounded by construction — developments popping up nearby.
Still, there is much work to be done before the T can celebrate.
The extension will have to pass federal safety certifications, Poftak said, and the T is still working on finishing the two new stations and training drivers. The timing of the opening of the much longer second branch to Medford, which includes five new stations, was tentatively scheduled for May, but may not start carrying passengers until summer.
“We’re still working to nail that down,” Poftak said.
The Green Line extension will be the first new subway branch to open in Boston since 1987, when the Orange Line extended from Back Bay to Forest Hills, according to MBTA spokesperson Joe Pesaturo. The $2.3 billion project has been discussed for decades and faced countless starts and stops.
In 1990, the state promised to extend the Green Line to “Ball Square/Tufts University” as part of an agreement with the Conservation Law Foundation, a legal advocacy group, to mitigate the environmental impacts of the Big Dig, which buried Interstate 93 beneath the center of the city. The foundation sued the state in 2005, accusing it of stalling the project, and settled in 2007 when the government agreed to complete it by 2014.
The state clearly didn’t make that deadline. In early 2015, the state won a $1 billion federal grant for the extension, but later that year, Massachusetts halted the project and considered scrapping it entirely after the total cost ballooned to $3 billion. At the time, the MBTA said the project had suffered from too little oversight, an accelerated timeline, and a mishandled bidding process.
After some cost cutting, in November 2017, the MBTA’s oversight board voted unanimously to award the design and construction contract to GLX Constructors, a joint venture of several construction and design companies.
Construction on the 4.7-mile project to Somerville and Medford began in 2018 with the goal of beginning passenger service at the seven new stations by December 2021.
Last year, the MBTA pushed back the Union Square branch opening to March 2022, citing complications in building its substations, and the delivery date on the Medford branch, which terminates at Tufts University, to May 2022, citing supply chain impacts from the COVID-19 pandemic.
There were many lessons learned by the seemingly never-ending series of delays, Poftak said, including the need to dedicate a team within the T to focus solely on the project. That change, made around 2015, has paid off, Poftak said.
“It’s really exciting to see not only a project . . . that is going to be of a great benefit to our customers, but a project that was, frankly, dead, that essentially crashed and burned in 2015 and 2016,” he said.
Staci Rubin, vice president of environmental justice at the Conservation Law Foundation, said dedicating a team made a difference in getting the project moving faster.
“Here we are years later and it’s thrilling that with all of the ups and downs we are finally seeing Green Line trains rolling through,” she said. “It’s wonderful, it’s long overdue, and it’s going to make a big difference for a lot of residents.”
As part of the foundation’s settlement with the state in 2007, the state committed to extending the Green Line to Route 16, further than the current project calls for. Rubin said the foundation views the branches to Union Square and Tufts as the first phase of the Green Line extension and is urging the MBTA to complete an environmental impact review and cost assessment of adding a Route 16 station.
“It is really important to get this over the finish line,” she said. As currently planned, Rubin said, the Medford branch doesn’t meet the 2007 agreement.
Poftak said the Route 16 addition is still in the “planning and permitting phase.”
“That’s obviously a huge funding hurdle,” he said.
Poftak said he is confident the Green Line extension, excluding a further extension to Route 16, will remain within its $2.3 billion budget, so confident that the MBTA recently returned funds to Somerville and Cambridge that the cities had provided for the project.
The T expects shuttle buses to continue to replace subway service between Lechmere and North Station until the night before service begins on the new branch, said Pesaturo. Poftak said he’s working on a specific day in March for the ribbon cutting.
“I was at the groundbreaking I don’t know how many years ago, and someone said, ‘You know this is the fifth groundbreaking I’ve been to for the Green Line extension,’ ” he said. “Well, we’re gonna cut the ribbon in March and actually get it done.”
Taylor Dolven can be reached at email@example.com. Follow her on Twitter @taydolven.