Fairmount Line Trains at Morton Street

MBTA Commuter Rail (operated by Keolis) Fairmount Line Trains No. 916 and 917 are seen here at Morton Street Station in Dorchester. The "Fairmount Line" is the name given by the MBTA to the local trains that operate along the innermost section of the former New Haven Railroad Midland Division, which continued southwest to Dedham, Norwood, Franklin, and ultimately Hartford, Connecticut. Only the northernmost sections of the Midland Division remain in passenger service today. See the Franklin Line video for a more detailed explanation of this former railroad corridor.
Today, most trains operating over the Midland Division between Franklin and Boston switch onto the Northeast Corridor (ex-Shore Line) at Readville Junction, and run express to Boston, usually stopping only at Ruggles and Back Bay (some also stop at Forest Hills during rush hours). The innermost section of the line through Dorchester, with seven additional local stops, is served by its own dedicated trains that operate between Boston and Readville only - these trains connect with Franklin Line trains at certain times, but at other times do not. Despite operating more frequently than any other MBTA Commuter Rail line (headways are roughly every 45 minutes on weekdays and every 90 minutes on weekends), the practice of relegating the Dorchester section of the line to its own long shuttle trains of sorts has been controversial. Dorchester is historically one of the lowest income sections of Boston, and is also a predominantly Black region. It is also one of the most transit-starved communities in the city, with no direct rapid transit connections to downtown. Residents must contend with long and slow bus rides that then require a transfer to the subway, or relatively infrequent commuter rail service. Various proposals have been made over the years for how to improve service, ranging from outright abandonment of the Dorchester rail line and converting the corridor to a rapid transit service, to simply rerouting most Franklin Line trains onto the local route instead of the express NEC route. The latest proposals involve purchasing a fleet of either diesel multiple units (DMUs) or battery electric multiple units (BEMUs) to replace the push-pull trains currently operating on the line. These vehicles would be more efficient to operate, and would travel at faster speeds, which in turn would reportedly allow headways to be increased to 30 minutes on weekdays and 45-60 minutes on weekends.