32 (MBTA bus)

Massachusetts Bay Transportation Authority (MBTA) Primary Bus Routes
Company type	Public transit service
Industry	Public transportation
Founded	2004
Area served	Boston, Massachusetts, United States
Key people	Marty Walsh (Mayor of Boston, associated with Go Boston 2030 plan)
Products	Bus transit services
Parent	Massachusetts Bay Transportation Authority (MBTA)

Primary bus routes of the Massachusetts Bay Transportation Authority (MBTA) referred to 15 routes with the highest ridership, held to more stringent frequency requirements according to the 2004 MBTA Service Policy. Collectively, these routes represented roughly 40% of the MBTA's total bus passenger volume. They delivered vital transit service within Boston’s most densely populated districts and linked seamlessly with other MBTA modes to broaden regional connectivity.

Designated as a crucial component of the MBTA’s core transit network, these primary bus routes were prominently displayed on updated system maps available at subway stations and public venues alongside rapid transit and commuter rail lines. They were categorized separately to focus on targeted service enhancements, such as pilot programs for late-night operations. Given their substantial ridership, these routes played a significant role in urban development planning and transportation engineering research. With the introduction of the 2024 Bus Network Redesign, the "key bus route" classification is being replaced by a more inclusive high-frequency route network.

History

The MBTA launched an initiative in November 2006 aimed at improving service quality on its primary bus routes. The 2008 Service Plan proposed enhancements for multiple lines, including upgrading Route 31 to meet key route criteria. Subsequently, a second $10 million Key Routes Improvement Project was funded through the American Recovery and Reinvestment Act of 2009. Although Silver Line services were initially part of this program, they were later managed independently. The project concluded in 2013, with some planned improvements remaining incomplete. Despite this, key routes maintained superior reliability compared to other routes—achieving 75% adherence to scheduled frequencies versus 61% as of June 2017.

A study conducted in 2012 revealed that areas near primary bus routes experienced decreased taxicab trip generation, suggesting that these frequent-service routes effectively competed with taxi demand where available.

In April 2014, a trial extension of late-night service was introduced on both key bus and rapid transit lines for one year, contingent on ridership levels and sponsorship support. By April 2015, service hours were reduced and some routes discontinued late-night operations altogether; by March 2016, late-night service was fully ended.

Primary bus routes were integral to Boston Mayor Marty Walsh’s "Go Boston 2030" plan, which sought to ensure that every household is within a ten-minute walk of either a T station or a primary bus stop. The proposal also included establishing a new key route linking the Longwood Medical Area with JFK/UMass via Roxbury.

In May 2022, the MBTA unveiled a draft Bus Network Redesign outlining changes to most primary bus routes while elevating others to form a high-frequency network complementing rapid transit services. A revised version of this plan was published in November 2022.

Criteria for key routes

According to the MBTA's Service Delivery Policy, Key Bus Routes are selected based on five factors:

Elevated ridership demand
Integration within the transit system
Broad geographic coverage
Support for significant new developments
Operation under bus rapid transit standards

Service standards

Key routes are required to uphold higher minimum standards than local routes regarding both hours of operation and service frequency.

Route Type	Minimum span of service
Local	Weekdays	7:00 AM – 6:30 PM
	Saturdays	8:00 AM – 6:30 PM
	Sundays	10:00 AM – 6:30 PM
Key	Weekdays	6:00 AM – Midnight
	Saturdays	6:00 AM – Midnight
	Sundays	7:00 AM – Midnight

Route Type	Minimum frequency of service
Local	Peak periods (AM & PM)	Every 30 minutes
	Off-peak times	Every 60 minutes
	Weekends (Sat & Sun)	Every 60 minutes
Key	Peak periods (AM & PM)	Every 10 minutes
	Midday hours	Every 15 minutes
	Evenings and weekends (Sat & Sun)	Every 20 minutes

Route list

The MBTA has identified 15 primary routes for focused service enhancements: 1, 15, 22, 23, 28, 32, 39, 57, 66, 71, 73, 77, 111, 116, and 117. These corridors are targeted for improvements such as limited-stop or express service options to boost efficiency and address the needs expressed by public officials and community members.

1

The 1 Harvard Square–Nubian Station line connects Cambridge with Roxbury. It originated in September 1962 through the consolidation of two routes divided at Massachusetts Avenue: route 76 Harvard–Massachusetts station and the former 47 Massachusetts station–Dudley. In May 1987, the alignment was shifted off Washington Street southeastward to Albany Street and Melnea Cass Boulevard to provide service to Boston Medical Center. The route mainly follows Massachusetts Avenue, traveling from Harvard past the Massachusetts Institute of Technology, crossing the Charles River via the Harvard Bridge, continuing through Boston near the Berklee College of Music, then reaching Boston Medical Center before heading southwest to Nubian station via Albany Street and Melnea Cass Boulevard.

As of 2015, Cambridge planned to implement signal priority at certain intersections along route 1 to enhance transit flow. No modifications to this route were suggested in the May and November 2022 network proposals.

In October 2023, Transitmatters identified route 1 as the slowest MBTA bus line with a significant issue of bus bunching—averaging a speed of just 6.55 mph and experiencing a bunching rate of 17.7%, highlighting considerable operational challenges.

15

The 15 Fields Corner Station or St. Peter's Square–Ruggles Station bus travels from St. Peter's Square in northern Dorchester northward along Bowdoin Street, then west on Hancock Street, proceeding north on Columbia Street to Uphams Corner. It continues west on Dudley Street to Nubian station, then follows Malcolm X Boulevard westward before heading north on Tremont Street to reach Ruggles station. During nights and weekends, service ends at Fields Corner station, with buses running via Geneva Avenue and Bowdoin Street back to St. Peter's Square.

This route replaced trackless trolleys on April 6, 1962, originally operating as the 15 Kane Square–Dudley line via Uphams Corner and Dudley Street. Following the Orange Line’s relocation to the Southwest Corridor in May 1987, it was extended to Ruggles. On August 25, 2024, Kane Square service was slightly lengthened to reach St. Peter's Square.

The draft network plan released in May 2022 proposed extending this route westward to Oak Square, replacing route , thereby creating an Oak Square–Fields Corner corridor. However, the November 2022 revision scaled back this extension to terminate at Ruggles instead, maintaining route 65 as a separate service.

22

The 22 Ashmont Station–Ruggles Station via Talbot Ave operates from Ashmont heading northwest toward the former location of Egleston station, then proceeds northward along Columbus Avenue and Tremont Street, following the Orange Line corridor before concluding at Ruggles.

Trackless trolleys were replaced by buses on April 6, 1962, with the route initially designated as 22 Ashmont–Dudley via Talbot and Warren, terminating at . In May 1987, the route was extended to reach Ruggles concurrent with the Orange Line’s relocation to the Southwest Corridor. Proposals in the May and November 2022 network plans suggested modifying its inner terminal to serve the Longwood Medical Area.

23

The 23 Ashmont Station–Ruggles Station via Washington Street shares its start and end points with route 22 but follows an alternate course. Departing from Ashmont on Talbot Avenue, it turns north onto Washington Street, continues along Warren Street to Nubian station, then heads west on Malcolm X Boulevard toward Roxbury Crossing, and finally travels north on Tremont Street to reach Ruggles.

Buses replaced trackless trolleys on April 7, 1962. The route’s extension to Ruggles coincided with the Orange Line’s move in May 1987. A 2017 study highlighted overcrowding issues on routes 23 and 28, recommending enhancements by extending route 29 and increasing its frequency. From March 1, 2022, through February 28, 2026, a city-funded fare-free initiative covers routes 23, 28, and 29. No modifications to route 23 were included in the May or November 2022 network proposals.

28

The 28 Mattapan Station–Ruggles Station route serves the Grove Hall and Mattapan neighborhoods along Blue Hill Avenue, a major arterial corridor. Blue Hill Avenue historically functioned as a busy trunk line; for instance, in 1945, route 29 Mattapan–Egleston operated with headways of approximately 1.5 minutes during morning peak periods. Streetcars ran on a dedicated right-of-way until buses replaced them in 1955. Route 28 was introduced in May 1987 as a supplement to route 29; by December 1989, route 28 became the main service along Blue Hill Avenue, while route 29 was limited to rush hours and shorter trips. Passenger shelters were installed in 2001. Between December 2006 and June 2010, morning peak short-turn trips operated under route number 25.

Multiple Silver Line expansion concepts were evaluated in the 2003 Program for Mass Transportation, including a bus rapid transit (BRT) overlay for route 28 as part of Silver Line Phase III plans developed in 2006. In 2009, state officials proposed the 28X, a limited-stop BRT service along this corridor—the busiest bus corridor in New England—featuring dedicated bus lanes and queue jumpers. The $114 million initiative aimed for construction commencement in April 2010 and service launch by early 2012.

The plan encountered significant opposition over concerns including inadequate community engagement, loss of parking spaces, and prolonged construction impacts. Consequently, the state withdrew the proposal late in 2009. In June 2010, the MBTA introduced articulated (60-foot) buses on route 28 to boost capacity despite residents’ objections regarding stop removals in the hilly Grove Hall area. A transit study conducted in 2012 recommended implementing the proposed express service as an express bus without building new infrastructure.

In August 2020, MBTA and City of Boston jointly applied for $15 million in federal funding toward a $30 million Blue Hill Avenue reconstruction project featuring center-running bus lanes targeted for completion by late 2021. This federal request was denied in September 2020. A subsequent $25 million application was submitted in July 2021. From August 29, 2021, through February 28, 2022, a $500,000 city-funded pilot program offered fare-free rides and all-door boarding on route 28 to improve travel times. Following this pilot, fare-free service on routes 23, 28, and 29 was extended through February 2026 under city sponsorship. In November 2021, Boston secured a $15 million federal grant toward the $39.5 million Blue Hill Avenue reconstruction effort.

The network plans released in May and November of 2022 proposed extending route 28 from Roxbury Crossing to via Longwood Medical Area while eliminating service between Roxbury Crossing and Ruggles. In February 2024, Boston announced a $44 million Blue Hill Avenue reconstruction project that includes center-running bus lanes with construction anticipated to begin in 2026.

32

The 32 Wolcott or Cleary Square–Forest Hills Station line operates along Hyde Park Avenue, linking Forest Hills to Readville and providing service through Jamaica Plain, Roslindale, and Hyde Park. Its entire path runs adjacent to the commuter rail tracks.

Prior to 1953, this route functioned as a full trolley service between Forest Hills and Cleary Square before transitioning to trackless trolley operation. By 1958, the trackless trolley service south of Forest Hills was substituted with diesel bus service. A turnaround loop for the trackless trolleys was situated at the intersection of Hyde Park Avenue and Pine Street.

In 1981, Route 31, which previously ran from Mattapan Square to Wolcott Square, was combined with Route 32 at Cleary Square, creating the Route 32 Forest Hills–Wolcott Square. Meanwhile, Route 50, which served Cleary Square and Forest Hills via Roslindale, was redirected to cover the Summer Street Elderly Housing area. The network plans released in May and November 2022 did not suggest any modifications to this route.

39

The 39 Forest Hills Station–Back Bay Station route was introduced in December 1985 as a replacement for the Green Line E branch service between Heath Street and Arborway. It shadows the Green Line corridor from Heath Street to Copley and offers connections to both the Orange Line and commuter rail at either terminus, including Amtrak services at Back Bay.

Route 39 was a pioneer in regular use of articulated buses within the MBTA system, a practice later adopted by other lines such as Route 28 by late 2005. By 2013, it ranked as Boston’s second busiest bus route. Its substantial ridership contributed to the expansion of Forest Hills station as part of the Casey Arborway project.

The draft network plan from May 2022 proposed extending Route 39 through several new areas, substituting segments of other routes while discontinuing service between Longwood Avenue and Back Bay. However, the November 2022 draft reversed these changes, restoring Route 39 to its original alignment and instead enhancing service frequency on Route 47 with an extension to Union Square.

57

The 57 Watertown Yard–Kenmore Station line serves the communities of Boston, Newton, and Watertown. It took over from the discontinued Green Line A branch in 1969. Previously, Route 57 operated limited-stop service within Boston—specifically avoiding pickups along Commonwealth Avenue between Packard's Corner and Kenmore—but this limited-stop pattern ended in December 2006. The May and November 2022 network proposals did not recommend any alterations for this route.

66

The 66 Harvard Square–Nubian Station via Allston route traces its origins as a trolley line. It starts at Nubian Square in Roxbury and crosses the Southwest Corridor Park near Roxbury Crossing. The route briefly follows portions of Route 39 and the Green Line E branch from Brigham Circle to Boston’s city limits. Traveling along Harvard Street, it serves neighborhoods including Brookline and Allston, detouring through Union Square (Allston) before proceeding along Cambridge Street and North Harvard Street to conclude at Harvard Square in Cambridge.

This route offers transfers to multiple transit lines: the Silver Line at Nubian station; Orange Line at Roxbury Crossing; Green Line E branch stops at Fenwood Rd, Mission Park, Riverway; Green Line D branch at Brookline Village; Green Line C branch at Coolidge Corner; Green Line B branch at Harvard Ave; and Red Line at Harvard station. No changes were proposed for this line in either the May or November 2022 network plans. In August 2024, northbound buses were rerouted into the Harvard Bus Tunnel.

71

The 71 Watertown Square–Harvard station route originates at the lower level of the Harvard bus tunnel, then proceeds south onto Mount Auburn Street before continuing westward into Watertown, terminating at Watertown Square.

At Harvard, buses complete their turnaround by leaving the tunnel and navigating a loop via Massachusetts Avenue, Garden Street, and Waterhouse Street. In Watertown, a dedicated private right-of-way loop enables efficient turning and passenger boarding.

Streetcar operations on the 71 ceased on September 4, 1958, subsequently replaced by trackless trolleys until March 13, 2022. In 2017, the 71 and 73 routes were chosen to participate in a bus rapid transit pilot initiative.

Together with routes and , routes 71 and 73 maintained trackless trolley service long after other MBTA trolleybus lines were discontinued, representing the final remnants of Boston’s trolleybus network. Conversion to diesel buses occurred in March 2022. The MBTA’s May and November 2022 network proposals indicated no adjustments for these routes; however, Watertown plans to extend route 71 slightly to reach Watertown Yard as part of reconfiguring Watertown Square.

73

The 73 Waverley Square–Harvard Station begins at the Harvard bus tunnel and shares Mount Auburn Street with route 71 through Cambridge and Watertown. It then branches onto Belmont Street along the border between Belmont and Watertown, continuing along Trapelo Road in Belmont to terminate at Waverley Square, looping at the Waverley commuter rail station on the Fitchburg Line.

Initially served by streetcars until the late 1950s, route 73 introduced trackless trolleys in 1957 for short-turn operations and fully transitioned in 1958. This trackless trolley service persisted until March 13, 2022. The MBTA’s May and November 2022 network plans did not propose any changes for this route.

77

The 77 Arlington Heights–Harvard Station connects Arlington with Harvard station along Massachusetts Avenue. Before the Red Line Northwest Extension in the 1980s, routes 77/77A provided primary transit service northwest of Harvard, with combined streetcar frequencies under one minute during peak periods in 1945. Route 77 switched to diesel buses in 1955; meanwhile, route 77A (a Harvard–North Cambridge carhouse short-turn) became a trolleybus line in 1958 to free up streetcars for the Highland branch conversion and eliminate boarding islands for vehicle traffic. Route 77A managed local stops south of the carhouse, while route 77 made limited stops there; from 1998 to 2005, route 77 largely supplanted route 77A service, which was fully discontinued in 2022. In 2017, Arlington pursued private funding for signal priority measures, queue jumps, and potential bus lanes along its segment. No modifications were suggested in the MBTA’s May and November 2022 network proposals.

111

The 111 Woodlawn–Haymarket Station links downtown Boston with parts of Chelsea via the Bill Russell Bridge and Tobin Bridge. Originally operated as streetcars between Chelsea Square and Woodlawn following the Boston Elevated Railway acquisition in 1936, it was replaced that October by an extended City Square–Chelsea Square bus route. The line extended to Haymarket in April 1975 after the closure of the Charlestown Elevated, with partial extensions beyond Woodlawn introduced in January 2001. Service beyond Woodlawn ended in September 2019; Cary Square short-turn trips were replaced by Woodlawn trips as of December 2021.

The 111 ranks among the MBTA’s highest-frequency numbered bus routes, offering service every five minutes during peak hours. No changes were included in either the May or November 2022 network plans.

116/117

The 116 Wonderland Station–Maverick Station via Revere Street and 117 Wonderland Station–Maverick Station via Beach Street routes connected East Boston, Chelsea, and Revere. While both lines followed largely the same course through East Boston and Revere, their paths diverged in the vicinity of Wonderland. According to the network proposals from May and November 2022, route 117 was planned for elimination, with the section between Broadway and Wonderland Station incorporated into an extended route to maintain high-frequency service on this corridor. This adjustment was implemented on December 15, 2024.

External links

MBTA – routes , , , , , , , , , , , , , ,
MBTA - Key Bus Route Improvement Program