The first Green Line trains have arrived in Somerville for a four-month testing period before the Green Line Extension's new Union Square branch opens for passengers in December.
In their monthly Community Working Group virtual hearing on Tuesday afternoon, project managers working on the Green Line Extension (GLX) announced that three older Green Line trains had been delivered to the newly-completed vehicle maintenance facility in the Brickbottom district.
In the coming weeks, those trains will venture out onto the new tracks of the Union Square branch for four months of "systems integration testing" to work out any remaining kinks before the new line opens in mid-December.
Testing for the longer Medford branch, which will run along the Lowell commuter rail line to Tufts University, will begin later this winter in preparation for a May 2022 opening date.
There's also been considerable progress on the new Somerville Community Path, which is also part of the GLX project. Several segments of the new trail have been paved this summer (like the access ramp to Cross Street, pictured above), but GLX project managers said on Tuesday that the path wouldn't open to the public until the rest of the project is complete next May, because the trail is still being used for construction access.