The Green Line is a semi-metro system run by the Massachusetts Bay Transportation Authority (MBTA) in the Boston, Massachusetts, metropolitan area. It is the oldest MBTA subway line, and with tunnel sections dating from 1897, the oldest subway in North America. It runs underground through downtown Boston, and on the surface into inner suburbs via six branches on radial boulevards and grade-separated alignments. With an average daily weekday ridership of 137,700 in 2019, it is the third most heavily used light rail system in the country. The line was assigned the green color in 1967 during a systemwide rebranding because several branches pass through sections of the Emerald Necklace of Boston.
The Massachusetts Bay Transportation Authority (MBTA) system is mostly but not fully accessible. Like most American mass transit systems, much of the MBTA subway and commuter rail were built before wheelchair access became a requirement under the Americans with Disabilities Act of 1990. The MBTA has renovated most stations to be compliant with the ADA, and all stations built since 1990 are accessible. The MBTA also has a paratransit program, The Ride, which provides accessible vehicles to transport passengers who cannot use the fixed-route system.
Central station is a Massachusetts Bay Transportation Authority (MBTA) rapid transit station in Cambridge, Massachusetts. It serves the Red Line and has a street-level terminal for the MBTA bus system. It is located at the intersection of Massachusetts Avenue with Western Avenue, Prospect Street, and Magazine Street at Central Square.
Downtown Crossing station is an underground Massachusetts Bay Transportation Authority (MBTA) rapid transit station located in the Downtown Crossing retail district in the downtown core of Boston, Massachusetts. It is served by the Orange Line and Red Line, and is one of four "hub stations" on the MBTA subway system. Downtown Crossing is also a major bus transfer location serving 13 MBTA bus routes, including one Silver Line route. It is the second busiest subway station in the MBTA network, with an average of 24,074 entries per weekday in FY2019.
Longwood Medical Area station is a light rail stop on the MBTA Green Line E branch, located in the Mission Hill neighborhood of Boston, Massachusetts. It is named for the adjacent Longwood Medical Area.
Brigham Circle station is a station on the light rail MBTA Green Line "E" branch, located just east of Brigham Circle in the Mission Hill neighborhood of Boston, Massachusetts. With raised platforms installed in a 2001-03 renovation, the station is accessible when served by low-floor streetcars.
Northeastern University station is a surface-level trolley stop on the MBTA Green Line. It is located in a dedicated median along Huntington Avenue in Boston, between Opera Place and Forsyth Street, and is adjacent to the Krentzman Quad on the campus of Northeastern University. It is the first surface-level stop going outbound along the Green Line E branch; trolleys rise from a portal located between Opera Place and Gainsborough Street and continue along the surface down Huntington Avenue towards Mission Hill.
Heath Street station is a Massachusetts Bay Transportation Authority (MBTA) Green Line light rail station in Boston, Massachusetts. It is the southwestern terminus of the Green Line E branch. It is located at the intersection of South Huntington Avenue and Heath Street on the border between the Mission Hill and Jamaica Plain neighborhoods.
Coolidge Corner station is a light rail stop on the MBTA Green Line C branch, located at the intersection of Beacon Street and Harvard Street in the Coolidge Corner neighborhood of Brookline, Massachusetts. With 3,440 daily boardings by a 2011 count, it had more than twice the ridership of any other surface station on the branch.
The E branch is a light rail line in Boston, Cambridge, Medford, and Somerville, Massachusetts, operating as part of the Massachusetts Bay Transportation Authority (MBTA) Green Line. The line runs in mixed traffic on South Huntington Avenue and Huntington Avenue between Heath Street and Brigham Circle, in the median of Huntington Avenue to Northeastern University, then into the Huntington Avenue subway. The line merges into the Boylston Street subway just west of Copley, running to North Station via the Tremont Street subway. It then follows the Lechmere Viaduct to Lechmere, then the Medford Branch to Medford/Tufts. As of February 2023, service operates on eight-minute headways at weekday peak hours and eight to nine-minute headways at other times, using 13 to 17 trains.
The C branch, also called the Beacon Street Line or Cleveland Circle Line, is one of four branches of the Massachusetts Bay Transportation Authority's Green Line light rail system in the Boston, Massachusetts metropolitan area. The line begins at Cleveland Circle in the Brighton neighborhood of Boston and runs on the surface through Brookline along the median of Beacon Street. Reentering Boston, the line goes underground through the St. Mary's Street incline and joins the B and D branches at Kenmore. Trains run through the Boylston Street subway to Copley where the E branch joins, then continue through the Tremont Street subway to downtown Boston. The C branch has terminated at Government Center station since October 2021.
The Green Line D branch is a light rail line in Boston, Brookline, Cambridge, Newton, and Somerville, Massachusetts, operating as part of the Massachusetts Bay Transportation Authority (MBTA) Green Line. The line runs on a grade separated surface right-of-way for 9 miles (14 km) from Riverside station to Fenway station. The line merges into the C branch tunnel west of Kenmore, then follows the Boylston Street subway and Tremont Street subway to North Station. It is the longest and busiest of the four Green Line branches. As of February 2023, service operates on 8 to 9-minute headways at weekday peak hours and 8 to 11-minute headways at other times, using 13 to 19 trains.
Fenway station is a light rail stop on the MBTA Green Line D branch, located under Park Drive near the Riverway in the Fenway–Kenmore neighborhood of Boston, Massachusetts. It opened along with the rest of the D branch on July 4, 1959, when trolleys replaced Highland branch commuter rail service. The station is fully accessible from Park Drive via the Landmark Center parking lot, as well as from Miner Street. Named after the Fenway parkway rather than Fenway Park, it is further from the stadium than Kenmore, though still used during events.
Cleveland Circle station is a surface light rail station on the MBTA Green Line C branch, located in the Brighton neighborhood of Boston, at Cleveland Circle. Cleveland Circle station is accessible, with raised platforms to accommodate low-floor light rail vehicles.
St. Mary's Street station is a surface light rail stop on the MBTA Green Line C branch, located just west of the intersection of Beacon Street and Park Drive in the northeastern tip of Brookline, Massachusetts. Like all surface stops on the line, St Mary's Street has two side platforms serving two tracks. The station is accessible. With just over 1,500 daily boardings by a 2011 count, St. Mary's Street is the second-busiest stop on the C branch, behind only Coolidge Corner.
Newton Centre station is a light rail station on the MBTA Green Line D branch, located in the Newton Centre village of Newton, Massachusetts. A former commuter rail station, it was converted for light rail use and reopened on July 4, 1959, along with the rest of the line. The 1891-built station and express office are part of the Newton Railroad Stations Historic District, which was placed on the National Register of Historic Places in 1976.
Washington Square station is a surface light rail stop on the MBTA Green Line C branch, located in the median of Beacon Street in the Washington Square neighborhood of Brookline, Massachusetts. Washington Square is the 4th-busiest surface stop on the line, with 1,091 daily boardings by a 2011 count. The station has two side platforms serving two tracks.
Brookline Hills station is a light rail station on the Massachusetts Bay Transportation Authority (MBTA) Green Line D branch in the Brookline Hills neighborhood of Brookline, Massachusetts. The station has two side platforms serving the line's two tracks. It was closed from April 2021 to January 2022 as part of adjacent construction on a Brookline High School building, which included renovations to make the station accessible.
Boston University Central station is a surface-level light rail station on the MBTA Green Line B branch, located the center median of Commonwealth Avenue west of St. Marys Street in Boston, Massachusetts, surrounded by the Boston University campus. It consists of two side platforms, which serve the B branch's two tracks. The station is accessible, with raised platforms to allow level boarding onto low-floor trams and a high platform on the inbound side to serve high-floor light rail vehicles.
Washington Street station is a surface stop on the Massachusetts Bay Transportation Authority (MBTA)'s Green Line B branch, located in Brighton, Boston. The station is located in the median of Commonwealth Avenue northeast of Washington Street. Washington Street station consists of two side platforms, which serve the B branch's two tracks. The station is fully accessible.
MBTA bus: 8, 19, 39, 47, CT2, CT3 
