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Green Line Transformation

Green Line Transformation logo

As part of our $8 billion, 5-year capital investment plan that began July 1, 2018, we’re rebuilding and transforming the Green Line.

We’ll be investing in projects to increase overall capacity on the Green Line, remove barriers to access, and make the system more resilient in the event of extreme weather. Along with the Green Line Extension (GLX) to Somerville and Medford, these short- and long-term projects will ensure that twice as many passengers have access to a safer, more comfortable, and more reliable Green Line by 2030.

Check out each project below, or explore our program map for more information.

Building a Better T

As part of our $8 billion, 5-year capital investment plan, we're renovating stations, modernizing fare collection systems, upgrading services for our buses, subways, and ferries, and improving the accessibility of the entire system.

Learn more


Every Green Line Transformation project meets at least one, sometimes many, of our program goals.

Green Line Extension (GLX)

GLX Rendering of Ball Plaza Station

We’re extending the northern end of the Green Line from Lechmere to Union Square in Somerville and College Avenue in Medford.

 Contract awarded: November 2017
 Projected completion: Fall 2021
 Budget: $2,118,600,000
 Status: 22% construction complete


  • Addressing Demand: 6 new subway stops in Cambridge, Medford, and Somerville; center platforms long enough for 3-car train sets
  • Accessibility: Fully accessible stations

Learn more about the Green Line Extension 

New Green Line Vehicles

New Green Line D vehicle at Kenmore

We’re putting 24 all-new, modern Green Line vehicles into service to prepare for increased ridership due to the Green Line Extension. These vehicles will expand the fleet from 189 to 213.

 Contract awarded: May 2014
 Projected completion: December 2019
 Budget: $170,000,000
 Status: First new vehicles went into service December 2018


  • Addressing Demand: 24 new vehicles to service the Green Line
  • Access: Low-floor entrances for step-free access

Learn more about the new Green Line vehicles

B Branch Station Consolidation

Rendering of the proposed station between Harry Agganis Way and Babock St, with a view of the platform.

We’ll consolidate 4 B Branch stations into 2, for faster, more reliable trips along Commonwealth Ave. 

 Contract awarded: Summer 2019
 Projected completion: 2021
 Budget: $29,328,818
 Status: 100% design; construction to begin in winter 2019/2020


  • Addressing Demand: Faster trips down Commonwealth Ave
  • Accessibility: Full high-level boarding platforms
  • Customer Experience: All-new benches, shelters, and safety features at each station

Learn more about the B Branch Station Consolidation

Newton Highlands Station Accessibility Improvements

Rendering of the planned ramp from Walnut St to the platform below

Newton Highlands Station will be upgraded so it’s accessible to people with disabilities, removing barriers to access on a portion of the Green Line.

 Contract awarded: Expected January 2020
 Projected completion: December 2022
 Budget: $22,969,104
 Status: 80% design


  • Access: Full high-level boarding platforms; multiple accessible pedestrian crossings
  • Customer Experience: New heated shelters, benches, bicycle storage, and in-station signs

Learn more about the Newton Highlands Accessibility Improvements

Solar-Powered E Ink Signs

Closeup of an E Ink sign on the outbound platform at Beaconsfield

We’re testing a variety of solar-powered E Ink signs that provide real-time train arrival information at some street-level Green Line stops.

Contract awarded: 2017
Projected completion: June 2020
Budget: $1.5 million
Status: Phase 1 pilot complete; phase 2 in planning and design


  • Customer Experience: Real-time train arrival times at more street-level Green Line stops

Learn more about E Ink

Green Line Intersection Upgrades

C Line intersection at Carlton and Beacon streets, after intersection upgrade completed

We’ll replace sections of rail at vehicle crossings on the B Line, C Line, and the Mattapan Line to improve rider, pedestrian, cyclist, and driver safety. 

 Contract awarded: March 2019
 Projected completion: December 2019
 Budget: $21,000,001
 Status: 60% construction complete


  • Access: New pedestrian pathways at 18 stations
  • Safety: New rail and pavement at 30 crossings to mitigate risk of service interruptions due to track conditions
  • Customer Experience: Safer pedestrian, vehicle, and bicycle crossings

Learn more about Intersection Upgrades 

D Branch Track and Signal Replacement

Placing new railroad ties along the D Branch (November 2018)

We’ll replace 25,000 feet of track and 6.5 miles of signals between Beaconsfield and Riverside for faster, more reliable service on the Green Line D Branch. 

 Contract awarded: June 2018
 Projected completion: December 2020
 Budget: $101,600,453
 Status: 26% construction complete


  • Service Delivery: Speed restrictions lifted on some sections of the Green Line for faster service
  • Safety and Resiliency: New tracks and signals mitigate main causes of derailments and reduce time and money needed for maintenance

Learn more about Green Line D Track and Signal work 

Fenway Portal Project

A three-person construction crew stands on the left as a Green Line D train exists the Fenway Portal and pulls into Fenway Station.

We’re adding large steel doors to the entrance of the Green Line tunnel near Fenway Station to prevent flooding. 

 Contract awarded: March 2018
 Projected completion: Spring 2020
 Budget: $22,187,285
 Status: 40% construction complete


  • Safety and Resiliency: Reduce risk of damage from flooding in the Green Line central tunnel

Learn more about Fenway Portal work

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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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

For More Information

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Building a Better T

As part of our $8 billion, 5-year capital investment plan, we're renovating stations, modernizing fare collection systems, upgrading services for our buses, subways, and ferries, and improving the accessibility of the entire system.

Learn more