The Green Line Extension (GLX) is a project which seeks to create rapid transit into Cambridge, Somerville, and Medford. While these areas are neighbors of Boston and represent large populations of daily commuters into the city, they are historically underserved regarding rapid transit. The proposed extension includes seven new stations across two branches. The project’s primary goals are to reduce vehicle trips and vehicle miles traveled, establish rapid transit to underserved areas, use of existing rail right of ways to mitigate construction impacts and to make fully accessible stations for people of all abilities. There are additional plans to include the relocation of Lechmere Station in Cambridge to a new site.
The project is estimated to cost $2.1 billion and will stretch from initial planning phases in 2014 to full build completion in 2021. Funding for the project will be shared between the Commonwealth and the Federal Transit Authority which, under the Full Funding Grant Agreement, will provide $996 million of total construction costs. In addition, the cities of Cambridge and Somerville contributed a small amount of funding. The project is currently under construction at 22 percent of its full build completion status. Much of the preliminary infrastructural work on northern sections of the proposed track area has been completed. Additionally, construction on new stations has begun in Union Square and the Brickbottom neighborhood of Somerville.
This project sets the stage for benefits to commuters in and out of Boston such as greatly reduced roadway congestion, creation of new public transit routes. GLX project managers estimate that residents in Somerville within walking distance of rapid transit will increase from 20 percent at the current level of service to approximately 80 percent following the project’s completion.