Project Overview

In addition to building a Vehicle Maintenance Facility (VMF), six new stations, and relocating one current station, the Green Line Extension Project (Project) will create two new branches of the Green Line, extending from Lechmere Station to Union Square Station and to College Avenue Station. The GLX will open for service in December 2021.

Click here for a proposed Project map.

The Green Line Extension Project includes:

Relocating approximately three-and-a-half miles of New Hampshire Main Line double track

Constructing new Medford Branch Green Line tracks

Relocating approximately one mile of Fitchburg Commuter Rail double track

Constructing new Union Square Branch Green Line tracks

Building six new stations:

- East Somerville
- Gilman Square
- Magoun Square
- Ball Square
- College Avenue
- Union Square

Relocating one station:

- Lechmere

Improving some roadways and intersections

Constructing a Vehicle Maintenance Facility


Signal and Communication

Replacing and rehabilitating several bridges

Improving non-automobile travel by coordinating transit and bicycle/pedestrian facilities

For more information about the Green Line Extension Project, visit the Project website: