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Bridge Closures to Support Green Line Extension Begin March 22

8- to 12-month detours planned around work zones on Broadway, Washington St., and Medford St.

To complete the next phase of work on the Green Line Extension (GLX) Project, the Broadway bridge, between Ball Square and Magoun Square, will close for construction for approximately one-year beginning March 22. This is the first in a series of three 8- to 12-month closures planned for 2019: Closures on Washington St. and Medford St. will follow in April and July, respectively. Wider bridges will be constructed at each location to accommodate the new light-rail service, among other improvements.
As noted, the Broadway bridge is expected to remain closed for a full year, through March 2020. Detours will be in place for all motorists, bicyclists, pedestrians, and MBTA bus routes 80 and 89.
Next, the Washington St. underpass, near McGrath Highway in East Somerville, will close for two separate phases: first, from April 2019 to Fall 2019, then again from Spring 2020 to Fall 2020. Detours will be in place for all motorists, bicyclists, pedestrians, and MBTA bus routes 86, 91, and CT2.
The third bridge to close in 2019 is on Medford St., behind Somerville High School. It will close from July 2019 through Spring 2020, and all motorists, bicyclists, and pedestrians will be rerouted.
Maps of each detour are available at

In coordination with the MBTA and its contractor, GLX Constructors (GLX-C), the City of Somerville is taking steps to protect public safety, minimize quality-of-life impacts to neighbors, and support affected businesses during these bridge closures. As part of those efforts, the City will provide two separate shuttle services, one around the Broadway bridge and one around the Washington St. bridge, during those closures to help ease impacts on pedestrians. Officials and public safety officers will also be onsite as each detour is implemented to monitor and manage traffic flows, collect data, and make adjustments as necessary.
The long-awaited Green Line Extension is expected to open to the public by the end of 2021. The project will bring seven new T stations to the region and extend the Somerville Community Path to North Point Park, near the Charles River in Cambridge. It will put 85% of Somerville residents within a half-mile of a subway stop and add almost 11 miles of new drainage infrastructure, and it’s expected to reduce traffic, improve air quality, and foster economic development.
The City of Somerville offers a number of ways to stay updated about construction. Anyone interested can sign up to receive a weekly email outlining upcoming construction citywide at Residents are also encouraged to enroll in the City’s alert system at to ensure they’re notified prior to major detours or disruptive construction activity in their neighborhood.
Anyone seeking assistance for an urgent construction-related matter can call the 24/7 GLX hotline at 1-855-GLX-INFO (459-4636) or email

For additional information about the Green Line Extension Project, including construction schedules, fact sheets, and the latest station designs, visit  

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