The Massachusetts Bay Transportation Authority (MBTA) operates 152 bus routes in the Greater Boston area. The MBTA has a policy objective to provide transit service within walking distance (defined as 0.25 mi) for all residents living in areas with population densities greater than 5000 PD/sqmi within the MBTA's service district. Much of this service is provided by bus. In, the system had a ridership of , or about per weekday as of. Most MBTA bus routes are local service operated in Boston and its inner suburbs and connect to MBTA subway stations. Fifteen high-ridership local routes are designated as key routes, with higher frequency at all operating hours. The MBTA operates a five-route bus rapid transit service branded as the Silver Line, as well as two limited-stop crosstown routes. Three smaller local networks are based in the nearby cities of Lynn, Waltham, and Quincy. Several express routes operate from suburbs to downtown Boston. The MBTA has an active bus fleet around 1,040 buses with diesel-electric hybrid or compressed natural gas propulsion. Replacement of the full fleet with battery electric buses is planned. The entire bus system is accessible; all vehicles are low-floor buses with fold-out ramps. Most routes are operated directly by the MBTA. Four suburban routes are run by private operators under contract to the MBTA, while several small circulator systems are run by other operators with partial MBTA subsidy. MBTA-operated buses operate from nine garages, one of which is under reconstruction and a second planned for replacement. Several sections of dedicated right-of-way for MBTA buses have been opened in the 21st century, including two off-street busways for the Silver Line and a number of dedicated bus lanes. The modern bus system descends from a network of horsecar and electric streetcar lines built in the 1850s to 1910s, which were consolidated under the West End Street Railway and later Boston Elevated Railway (BERy). The BERy introduced buses in 1922 to replace lightly-used streetcar lines and expand into new areas. Over the next four decades under the BERy and Metropolitan Transit Authority (MTA), all but six streetcar routes were converted to bus or trolleybus. Most trolleybuses were phased out by the 1960s, but four routes lasted until 2022. The MBTA took over the MTA in 1964, and several private suburban bus operators over the following two decades. Many routes have been modified during the MBTA era; the agency introduced crosstown routes in 1994 and the Silver Line in 2002.

History

A number of horsecar lines were built in Boston and surrounding towns in the second half of the 19th century, beginning with the Cambridge Railroad in 1856. Several smaller companies were consolidated into the West End Street Railway in 1887. The West End began electrifying existing lines and constructing new streetcar lines; the last horsecar lines ended in 1900. The West End was purchased in 1897 by the Boston Elevated Railway (BERy), which had been created to build a rapid transit system in Boston. As that system was constructed in the first two decades of the 20th century, many streetcar lines were cut back from downtown Boston to rapid transit stations. Stations like Sullivan Square, Dudley Square, Forest Hills, Harvard, and Andrew were built as transfer stations with easy connections between subway and rapid transit. Some small companies operated buses in Boston as early as the 1910s. BERy bus service began on February 23, 1922, when buses replaced the North Beacon Street streetcar line. Initial bus routes largely replaced lightly-used streetcar lines or expanded service to new areas. The BERy also attempted in the 1920s to make the Tremont Street streetcar subway operate more like a rapid transit line, using trains of streetcars entering the subway from a small number of feeder lines, rather than single streetcars from numerous surface lines. The Harvard–Lechmere streetcar line was converted to trackless trolley (trolleybus) on April 11, 1936 – the first route in what would become an extensive trackless trolley system. As increased automobile usage reduced ridership and increased congestion, the BERy and its 1947 replacement Metropolitan Transit Authority (MTA) continued to convert streetcar lines to bus and trolleybus. Most trolleybus lines were replaced by buses in the late 1940s to early 1960s, as buses offered increased flexibility and no need to maintain overhead lines. When the Massachusetts Bay Transportation Authority (MBTA) replaced the MTA in 1964, all surface lines were operated by buses except six streetcar lines (the five Green Line branches plus the Mattapan Line) and four trolleybus lines. The MBTA rebranded many elements of Boston's public transportation network in its first decade. After being found unsuitable in 1965 for the Orange Line because it did not show up well on maps, yellow was chosen for the color of bus operations on January 8, 1972. The MBTA had primarily been formed to subsidize the suburban commuter rail network. However, the agency also took over unprofitable suburban bus operations – much of which was former streetcar lines – from several private companies. The MBTA took over the Eastern Massachusetts Street Railway in 1968, inheriting large networks based in Lynn and Quincy plus several lines in Norwood and Melrose. (Networks serving Lowell, Lawrence, and Brockton outside the MBTA district were briefly operated by the MBTA. They were transferred to new public agencies: the LRTA in Lowell in 1976, a predecessor of the MVRTA in Lawrence in 1968, and a predecessor of the BAT in Brockton in 1969.) The MBTA began subsidizing Middlesex and Boston Street Railway service based in Newton and Waltham in 1964, and took over the remaining routes in 1972. Five former Service Bus Lines routes in northeast suburbs were taken over in 1975, and a single Brush Hill Transportation line in Milton was taken over in 1980. The geographic scope of the MBTA bus network has remained relatively constant since these additions, though many services have been created, discontinued, and modified during the MBTA era. The openings of new sections of the Red Line (1971, 1980, 1984–85) and the Orange Line (1975–77, 1987) have resulted in significant changes as routes were modified to serve new transfer stations. Three limited-stop crosstown routes were created in 1994 as a prelude to the Urban Ring Project, a never-implemented circumferential bus rapid transit (BRT) corridor. Silver Line BRT service began in 2002 with conversion of existing bus service on Washington Street, and was expanded in 2004–05 with new routes serving the Waterfront Tunnel in the Seaport District. The latter used dual-mode buses that operated as trolleybuses in the Waterfront Tunnel and as diesel buses on the surface. A second Silver Line service using the Washington Street corridor was added in 2009, and service from the Waterfront Tunnel to Chelsea began in 2018 with a new surface busway in Chelsea. The BERy and MTA operated overnight Owl service until 1960. From September 2001 to June 2005, the MBTA operated bus service on 17 routes (7 normal bus routes and 10 routes replicating subway lines) until 2:30am on Friday and Saturday nights. Similar service on the key routes was operated from March 2013 to March 2014. In 2017, the MBTA Board rejected a proposal to run all-night service on several routes with pulsed connections at a central hub. In 2018, the MBTA began planning for the Bus Network Redesign, a reworking of the entire bus network. A draft plan was released in May 2022, with a revised plan in November 2022. That plan was approved in December 2022. It increases overall service by 25%, with a doubling of the number of routes with high-frequency service. , the first changes are planned to be made on December 15, 2024, in areas northeast of downtown Boston. The second phase is planned to cover most of Boston and Brookline; the third and south phases are tentatively planned to cover northern and southern suburbs. Changes will take place through 2028. In 2022, the MBTA started cutting bus service due to a driver shortage resulting from a long-term retirement trend accelerated by the COVID-19 pandemic in Massachusetts. Despite paying for training to get a commercial driver's license and offering a $4,500 signing bonus, it ended the year short about 350 drivers, plus about 400 more needed to increase service to implement a proposed bus network redesign. Experts said the shortage was caused by the failure to raise the starting hourly wage, and offer new hires full-time work instead of forcing all of them to start part-time. Drivers were also unhappy about lack of access to bathrooms and "split shifts" with unpaid time between morning and evening rush hour that was too short to go home. The MBTA began hiring operators for full-time work in 2023. The number of bus drivers increased from about 1,350 in mid-2023 to about 1,500 in March 2024.

Fleet

This is the current bus roster for the MBTA. All buses are 102 in wide; most buses are 40 foot length, while 117 are 60 foot articulated buses. An additional 80 New Flyer 40-foot battery-electric buses were ordered in July 2023, with the first ten to be delivered in 2024 and the remainder in 2025–26. Thirty-two of those buses will have left-side doors for use in the Harvard bus tunnel.

Current

Future

Facilities

[[File:MBTA bus districts.svg|thumb|right|MBTA bus routes grouped by the facility they operate from at peak hours (2016) ]] MBTA buses are operated out of eight facilities.

Replacements

The North Cambridge bus facility, which was used by trackless trolleys until March 2022, is to be modified for battery-electric buses. A $27.3 million contract was issued in October 2023, with completion expected in November 2025. The MBTA plans to replace Quincy Garage with a larger facility near Quincy Adams station. The parcel was purchased for $38.2 million in March 2021. Early work, including demolition of an existing building at the site, was completed in mid-2022. Bids in May 2022 came in higher than expected – $360 million versus $280 million – prompting the MBTA to switch to Construction Management at Risk bidding for the project. , the work is expected to cost $299 million, with substantial completion in March 2027. A replacement of Arborway Garage on-site is planned to be completed in 2028. It will expand the fleet at that garage from 118 CNG buses to 200 battery-electric buses, including articulated buses for routes 28, 32, and 39. In July 2022, the MBTA indicated plans to purchase an adjacent parcel to expand Southampton Garage.

Private operators

Most local bus routes in Massachusetts outside the immediate MBTA operating area are operated by the state's other regional transit authorities (RTAs). However, some routes that connect with MBTA bus or subway service are operated by outside private contractors with partial subsidy by the MBTA. Four routes – the, , , and – are numbered like other MBTA buses. The four routes are primarily commuter routes which connect with other MBTA services at their inbound terminals. They were taken over from various private operators (Rapid Transit Inc. for the 712/713, Nantasket Transportation for the 714, and Hudson Bus Lines for the 716). The 712 and 713 use MBTA-provided buses; the other routes do not. Four suburban municipalities contract with outside operators for local circulator routes, most with partial MBTA subsidy. Bedford and Beverly run single routes, Burlington runs five routes, and Lexington runs six. Most are run by private operators, except for the Beverly Shuttle, which is part of the Cape Ann Transportation Authority system. Additionally, a nonprofit shuttle is run in Boston's Mission Hill neighborhood. Those routes appear on MBTA system maps and connect with MBTA services at designated transfer points, but are numbered separately and do not accept MBTA passes.

Bus lanes

Several sections of dedicated right-of-way for MBTA buses have been opened in the 21st century. Two sections of the Silver Line have off-street busways: The 2004-opened 1.2 miles South Boston Piers Transitway tunnel in the Seaport (used by the, , , and ), and a 2018-opened 1.1 miles surface busway in Chelsea used by the SL3. A direct ramp to the Ted Williams Tunnel is proposed for use by the SL1 and SL3. A number of dedicated bus lanes on surface streets are also in use: An additional 1.0 mile of center lanes on Columbus Avenue and Tremont Street between Jackson Square and Ruggles is planned for construction in 2025–26. Center bus lanes are also funded for Lynnway in Lynn, and proposed for Blue Hill Avenue in Boston between Grove Hall and Mattapan. Additional lanes in Boston announced in 2020 but not yet implemented include Malcolm X Boulevard between Roxbury Crossing and Nubian Square, Warren Street between Nubian Square and Grove Hall, and Hyde Park Avenue between Forest Hills and Metropolitan Avenue.