The Massachusetts Bay Transportation Authority is the public agency responsible for operating most public transportation services in Greater Boston, Massachusetts. The MBTA transit network includes the MBTA subway with three metro lines, two light rail lines, and a five-line bus rapid transit system ; MBTA bus local and express service; the twelve-line MBTA Commuter Rail system, and several ferry routes. In 2022, the system had a ridership of 216,329,500, or about 759,800 per weekday as of the first quarter of 2023, of which the rapid transit lines averaged 263,500 and the light rail lines 91,300, making it the fourth-busiest rapid transit system and the third-busiest light rail system in the United States. As of the first quarter of 2023, average weekday ridership of the commuter rail system was 81,800, making it the fifth-busiest commuter rail system in the U.S.
The Silver Line is a system of bus routes in Boston and Chelsea, Massachusetts, operated by the Massachusetts Bay Transportation Authority (MBTA). It is operated as part of the MBTA bus system, but branded as bus rapid transit (BRT) as part of the MBTA subway system. Six routes are operated as part of two disconnected corridors. As of 2019, weekday ridership on the Silver Line was 39,000.
Porter station is a Massachusetts Bay Transportation Authority (MBTA) transit station in Cambridge, Massachusetts. It serves the Red Line rapid transit line, the MBTA Commuter Rail Fitchburg Line, and several MBTA bus lines. Located at Porter Square at the intersection of Massachusetts and Somerville Avenues, the station provides rapid transit access to northern Cambridge and the western portions of Somerville. Porter is 14 minutes from Park Street on the Red Line, and about 10 minutes from North Station on commuter rail trains. Several local MBTA bus routes also stop at the station.
Haymarket station is an underground Massachusetts Bay Transportation Authority (MBTA) rapid transit station located at Haymarket Square in Boston, Massachusetts. It is a transfer station between the Green Line and Orange Line of the MBTA subway system, as well as a terminal for MBTA bus routes serving northern and northeastern suburbs. The two lines run parallel to each other through the station, with two side platforms for the Orange Line and a single island platform for the Green Line. The station is fully accessible.
Lechmere station is a Massachusetts Bay Transportation Authority (MBTA) Green Line light rail station in Lechmere Square in East Cambridge, Massachusetts. It is located on the east side of Monsignor O'Brien Highway near First Street, adjacent to the NorthPoint development. The accessible elevated station has a single island platform, with headhouses at both ends. It opened on March 21, 2022, as part of the Green Line Extension (GLX). Lechmere station is served by Green Line D branch and E branch service.
The Massachusetts Bay Transportation Authority (MBTA) operates two specially designated crosstown bus routes in the Boston, Massachusetts, United States area, called CT2 and CT3, and intended as limited-stop buses connecting major points. The two weekday-only routes largely parallel MBTA bus local routes, but with fewer stops to reduce travel times.
Key bus routes of the Massachusetts Bay Transportation Authority (MBTA) system are 15 routes that have high ridership and higher frequency standards than other bus lines, according to the 2004 MBTA Service Policy. Together, they account for roughly 40% of the MBTA's total bus ridership. These key bus routes ensure basic geographic coverage with frequent service in the densest areas of Boston, and connect to other MBTA services to give access to other areas throughout the region.
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 8-minute headways at weekday peak hours and 8 to 9-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 A branch or Watertown Line was a streetcar line in the Boston, Massachusetts, area, operating as a branch of the Massachusetts Bay Transportation Authority Green Line. The line ran from Watertown through Newton Corner, Brighton, and Allston to Kenmore Square, then used the Boylston Street subway and Tremont Street subway to reach Park Street station.
The Boston-area trolleybus system formed part of the public transportation network serving Greater Boston in the U.S. state of Massachusetts. It opened on April 11, 1936, with a large network operating for the next quarter-century. Measured by fleet size, the Boston-area system was the second-largest trolleybus system in the United States at its peak, with only the Chicago system having more trolleybuses than Boston's 463. After 1963, the only remaining portion was a four-route cluster operating from the Harvard bus tunnel at Harvard station, running through Cambridge, Belmont, and Watertown. The Massachusetts Bay Transportation Authority took over the routes in 1964.
As with many large cities, a large number of Boston-area streetcar lines once existed, and many continued operating into the 1950s. However, only a few now remain, namely the four branches of the Green Line and the Ashmont–Mattapan High-Speed Line, with only one running regular service on an undivided street.
Route 86 is a local bus route in Boston, Cambridge, and Somerville, Massachusetts, operated by the Massachusetts Bay Transportation Authority (MBTA) as part of MBTA bus service. It operates on a circumferential route between Sullivan Square station and Reservoir station via Union Square, Somerville, Harvard Square, and Brighton Center. In 2018, it had the 18th-highest weekday ridership on the system, though it ranked 37th by number of weekday trips. A 2018–19 MBTA review of its bus system found that route 86 had infrequent and unreliable service, including irregular scheduled headways, despite its high ridership and significance as a crosstown connecting route.
The Urban Ring was a proposed project of the Massachusetts Bay Transportation Authority and the Massachusetts Department of Transportation, to develop new public transportation routes that would provide improved circumferential connections among many existing transit lines that project radially from downtown Boston. The Urban Ring Corridor is located roughly one to two miles from downtown Boston, passing through the Massachusetts cities of Boston, Chelsea, Everett, Medford, Somerville, Cambridge, and Brookline. The project was expected to convert 41,500 car trips to transit trips daily.
Springfield Union Station is a train and bus station in the Metro Center area of Springfield, Massachusetts. Constructed in 1926, Springfield Union Station is the fifth-busiest Amtrak station in the Commonwealth, and the busiest outside of Greater Boston.
The Joseph Scelsi Intermodal Transportation Center is a transit facility located in downtown Pittsfield, Massachusetts. The $11 million facility is named after Joseph Scelsi, a longtime State Representative who represented Pittsfield. Owned by the Berkshire Regional Transit Authority (BRTA), it is serviced by local BRTA bus services, Amtrak intercity rail service, and Peter Pan intercity bus service. The second floor of the building houses two classrooms used by Berkshire Community College and Massachusetts College of Liberal Arts.
Route 20 is a bus route operated by the Maryland Transit Administration in Baltimore and its suburbs. The line currently runs from Security Square Mall east through downtown Baltimore to Baltimore City Hall. The main roads on which the line operates are Old Frederick Road, Baltimore Street, Fayette Street, and Boston Street. The line serves the communities of Westview, Edmondson Village.
Watertown Carhouse is a bus maintenance facility and former streetcar carhouse located in the southern section of Watertown, Massachusetts, across the Charles River from Watertown Square. As Watertown Yard, the site also serves as a bus depot serving local and express routes, with additional connections available at Watertown Square on the opposite end of the Watertown Bridge.
The Lechmere Viaduct is a concrete arch bridge connecting the West End neighborhood of Boston to East Cambridge, Massachusetts. Opened in 1912, the viaduct carries the MBTA's Green Line over the Charles River. It is adjacent to the Charles River Dam Bridge, but structurally separate.
The Ipswich Street line was a streetcar line in Boston and Brookline, Massachusetts. The line ran on Boylston Street and Ipswich Street in the Fenway–Kenmore neighborhood, and on Brookline Avenue through what is now the Longwood Medical Area to Brookline Village.
MBTA bus: 51, 57, 64, 66, 193, 501, 503 
