MBTA Commuter Rail

The MBTA Commuter Rail (reporting mark MBTX) system serves as the commuter rail arm of the Massachusetts Bay Transportation Authority's (MBTA's) transportation coverage of Greater Boston in the United States. Trains run over 429 mi (690 km) of track on 12 lines to 143 stations. It is operated under contract by Keolis.

In 2025, the system had a ridership of 29,707,200, or about 107,500 per weekday as of the fourth quarter of 2025, making it the fifth-busiest commuter rail system in the U.S., behind the three New York-area systems and the Chicago-area system. The lines' characteristic purple-trimmed coaches operate as far south as North Kingstown, Rhode Island, and as far north as Newburyport and as far west as Fitchburg, both in Massachusetts.

Trains originate at two major terminals in Boston – South Station and North Station. The only connection between the two halves of the system is the non-revenue Grand Junction Branch. The North–South Rail Link is a proposed tunnel between North Station and South Station to allow through-running service.

The system consists of twelve lines – four of which have branches – radiating from downtown Boston. Eight "southside" lines terminate at South Station, with four (Framingham/Worcester, Needham, Franklin/Foxboro, and Providence/Stoughton) also running through Back Bay station. Four "northside" lines terminate at North Station. The lines vary in length from the 9.2-mile (14.8 km) Fairmount Line to the 62.9-mile (101.2 km) Providence/Stoughton Line, with typical lengths in the 25–40-mile (40–64 km) range. The system has 429 miles (690 km) of revenue trackage and covers roughly the eastern third of Massachusetts plus central Rhode Island.

Most lines do not share trackage outside the Boston terminal areas, with several exceptions. The Providence/Stoughton Line and Franklin/Foxboro Line both use the Northeast Corridor between Readville and South Station, with the Needham Line also sharing the tracks between Forest Hills and South Station. The Fall River/New Bedford Line, Kingston Line, and Greenbush Line all use the Old Colony mainline between South Station and Braintree. The Haverhill Line and Newburyport/Rockport Line share tracks between North Station and near Sullivan Square. A small number of Haverhill Line trains use the inner Lowell Line and the Wildcat Branch, while some Franklin/Foxboro Line trains (including all weekend trains) use the Fairmount Line rather than the Northeast Corridor. Several Amtrak intercity routes run on MBTA tracks: the Acela and Northeast Regional over the Providence/Stoughton Line, the Lake Shore Limited over the Framingham/Worcester Line, and the Downeaster over portions of the Lowell and Haverhill lines. Private companies also operate freight service over much of the system (see § Freight service).

As of July 2025^[update], there are 143 active stations – 56 northside and 87 southside. Five additional stations (Prides Crossing, Mishawum, Hastings, Plimptonville, and Plymouth) are indefinitely closed due to service cuts during the COVID-19 pandemic. Several other stations are planned. South Station, North Station, and Back Bay all have MBTA subway and Amtrak connections; nine other stations have subway connections, and six others have Amtrak connections.

Stations range in size from small platforms like Islington to the sprawling downtown terminals. Most stations outside downtown Boston have one or two side platforms or a single island platform. Standard MBTA platforms are about 800 feet (240 m) long – enough for a nine-car train – and a minimum of 12 feet (3.7 m) wide for side platforms and 22 feet (6.7 m) wide for island platforms. 122 active stations are accessible, including all terminals and all stations with rapid transit connections; 21 are not. The MBTA uses 48-inch (1,200 mm)-high platforms for accessible level boarding, as is standard in the northeastern United States. Some accessible stations have full-length high platforms for accessible boarding on all cars; others only have "mini-high" platforms about 40 feet (12 m) long – which allow for level boarding on two cars – with the rest of the platform length not accessible.

The MBTA Commuter Rail system is operated by Keolis Commuter Services – a subsidiary of French company Keolis – under contract to the MBTA. The MBTA owns all passenger equipment and most stations. Most trackage is also owned by the MBTA. The Massachusetts Department of Transportation (parent agency of the MBTA) owns several portions of the Framingham/Worcester Line as well as the Grand Junction Branch, which is used for non-revenue equipment moves between the northside and southside lines. Pan Am Southern owns the section of the Fitchburg Line between Fitchburg and Wachusett, while Amtrak owns the section of the Northeast Corridor (used by the Providence/Stoughton Line) in Rhode Island.