The 2020-2024 MBTA Commuter Rail Extension Project was the one of the largest extensions of the MBTA Commuter Rail in Massachussets since its original opening in 1981. The extension saw the addition of routes to Springfield, Amherst, and Pittsfield, as well as the construction of the North-South Rail Link, which connects South Station and North Station. Construction officially commenced on July 7, 2020 and concluded on December 15, 2024. Passenger service began on January 1, 2026.



Discussions of extending the Framingham/Worcester Line to Springfield began in early May 2017. Currently, the line ended at Worcester's Union Station, and continuing on to Springfield required Amtrack's Lake Shore Limited. However, an extension would allow easier direct commuting to Boston from Springfield.