The Massachusetts Bay Transportation Authority (MBTA) and its operations and maintenance partner for its Commuter Rail service, Keolis Commuter Services (Keolis), have completed the replacement of over 28 miles of rail on the Fairmount Line.

The improvements prepare the line for the battery-electric trains that will be introduced in the coming years, while also maintaining safe, dependable service for current riders. This single project replaced more rail than the entire Commuter Rail system typically upgrades in a full year. Service on the line will resume on December 1, 2025, offering 30-minute frequencies for most of the day. Meanwhile, the existing Providence/Stoughton and Franklin/Foxboro schedules will stay in place for now to accommodate ongoing Amtrak repair work.

In July 2024, the MBTA Board of Directors approved a proposal from Keolis to electrify the Fairmount Line with battery-electric trains in mind for its future. The rail replacement was the first step in bringing these trains to the line. The new trains will provide faster, quieter and more reliable service with notably less air pollution in the environmental justice corridor served by the Fairmount Line. The passengers will benefit from smoother, quieter rides, more space and a modernized travel experience with less vibration. These trains will use hybrid power, with an onboard battery that charges when overhead catenary wires are available. The rail replacement work is the first step in bringing these trains to the line.

Crews replaced nearly 158,000 feet of rail as part of the US$12 million project launched in June 2024. The accelerated pace allowed the work to be completed on schedule while still keeping trains running during peak hours. During the rail upgrades, teams also tackled several additional improvements, such as power-washing and thoroughly cleaning all stations and platforms, removing graffiti, clearing trash along the right-of-way, cutting back vegetation, and enhancing drainage.