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Green Line Transformation

Updated on June 5, 2019

GLT logo. Green Line Transformation. Background of a new Green Line train.

About the Project

With over 200,000 daily riders, the Green Line is the nation’s busiest light rail. It’s also the oldest subway in the country, with the first train departing Boylston Station in 1897. Since then, the route has expanded to include 66 stations along 4 branches—1 that shares some of its right of way with vehicle traffic. Due to the route’s complexity, it presents unique challenges to our riders and operators, including speed restrictions, obsolete signal hardware, overcrowded vehicles, and a number of stations that present barriers to access.

The Green Line Transformation (GLT) is a range of projects that will modernize stations, update tracks, signals, and power systems, and adopt new state-of-the-art technology to meet the demands of a modern city. Overall, GLT will ensure that twice as many passengers have access to a safer, more comfortable, more reliable Green Line.

The program will be rolled out in 4 phases, designed to minimize disruptions to customers.


  • Faster, more reliable Green Line service
  • Stations that are safer and easier to access
  • New, larger Green Line trolleys to reduce impacts of overcrowding
  • More accessible Green Line trolleys with lower floors and extendable bridge plates
  • Weather resiliency measures to reduce flooding in tunnels during extreme weather
  • Faster boarding times through new fare payment system, Automated Fare Collection 2.0

Program Map

Use the filter tool on this interactive map to see which projects are currently being designed or already under construction. Additional projects being considered as part of the Green Line Transformation are not reflected here. The map will be updated when they are confirmed. 

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Program Timeline

Presentations to the Board

Learn more about the Green Line Transformation by watching and downloading the presentations for the Fiscal and Management Control Board (FMCB).

Contact Information

For all queries and comments related to Green Line Transformation, please contact


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