Green Line Extension

Lechmere Station rendering 2011

The Latest

April 2019

In late March and early April, the MBTA Green Line Extension team began closing streets in Somerville to construct new bridges over the future Green Line. Several bridges affect regional traffic heading to or from Cambridge. These include closures of Broadway in Ball Square and Washington Street between Union Square and East Somerville. The GLX team has posted more information on these closures at their website.

June 2018

On Monday, June 25, Green Line Extension broke ground. Elected officials and administration from the Federal and State government, Somerville, and Cambridge presided over the groundbreaking. You can find photos from the groundbreaking ceremony at the MBTA project website.

October - November 2017

On October 17, 2017, the MBTA filed a Notice of Project Change (NPC) for the Green Line Extension Project with the Executive Office of Energy and Environmental Affairs (EEA). The NPC presents a preliminary proposal for a one-mile extension of the Green Line along the MBTA Lowell Line commuter rail right of way from the currently planned terminus at College Avenue in Medford to Mystic Valley Parkway (Route 16) in Medford and Somerville. Read the full NPC.

EEA will now accept public comments on this document. Learn more about how to comment and about an upcoming Public Information Meeting on the NPC on Monday, November 20.

October 5, 2017

On September 28, 2017, the three competing shortlisted Design Build teams submitted proposals in response to the MBTA's Request for Proposals (RFP's) issued in May of this year. Proposals were received from: GLX Constructors, Green Line Partners, and Walsh Barletta Granite, JV. The submissions are now under formal review by the GLX Program Management Team. The date for issuance of Notice-to-Proceed to the selected Design Build team is now slated to occur on December 11, 2017.

In the meantime, early construction activities continue to focus on track and signal work in the vicinity of the future College Avenue Station in Medford and the Red Bridge junction in Somerville and Cambridge. These activities continue to advance on a 7-day-per-week schedule including weekend overnight work.

See the Green Line Extension web page for further details and to sign up for project updates.


The Green Line Extension (GLX) project is extending the MBTA's Green Line transit service to the north west, from a relocated Lechmere Station in Cambridge, to a spur ending in Union Square Somerville, and the main line to College Avenue in Medford.  From the project web site, benefits will include:

  • Provide new and better opportunities for residents and visitors to travel within their communities and within the region, address longstanding transportation inequities.
  • Result in fewer automobiles on local roads and help combat greenhouse gas emissions and other components of air pollution.
    Support municipal plans for sustainable growth and development.
  • Provide residents of environmental justice communities with faster rides to work and other destinations.

Funding has also been set aside to extend the project to Route 16 on the Medford / Somerville line. 

Click here for a GLX presentation (dated October 2, 2014) with information on GLX sustainability, project overview and updates, and upcoming public meetings.

At the same time, the relocation of Lechmere Station across O'Brien Highway is being coordinated with the build out of North Point by HYM Development.  HYM is responsible for the reconstruction of O'Brien Highway and is working closely with the City of Cambridge and the state to improve existing crossings, and to create new crossings to make the new station readily accessible to the East Cambridge neighborhood. 

Click here to see a link to a 2011 GLX station presentation for the Lechmere Station.

For More Information

For more information, contact Bill Deignan in the Environmental and Transportation Planning Division at 617/349-4632 or