Green Line Extension Project (GLX)

The Green Line Extension (GLX) project will extend the existing MBTA Green Line north of its current terminus at Lechmere Station to further service the communities of Somerville, Cambridge, and Medford.

The project involves construction of six new Green Line stations along two branches (the Medford Branch and Union Square Branch) along with the relocation and reconstruction of Lechmere Station.

The project will significantly reduce vehicle trips and related air emissions while increasing access to fast and reliable public transit service in historically underserved areas. The project is expected to support increased ridership of more than 50,000 passenger trips per day once completed.

For inquiries relating to GLX construction work please use our 24/7 Construction Hotline - (855) 459-4636. For all other Green Line Extension inquiries please contact the project at

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200 Inner Belt Road, Somerville, MA 02143

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Image credits:  MassDOT