Trolleybuses in Greater Boston
| Company type | Public transit system |
|---|---|
| Industry | Public transportation |
| Founded | 1936-04-11 |
| Fate | Permanently discontinued in 2023 |
| Successor | Massachusetts Bay Transportation Authority (MBTA) |
| Headquarters | Boston, Massachusetts , United States |
Area served | Greater Boston metropolitan area |
| Owner | Massachusetts Bay Transportation Authority (since 1964) |
| Website | www |
The trolleybus system in the Boston metropolitan area, often referred to locally as the "trackless trolley," played a significant role within the public transit framework of Greater Boston. It commenced service on April 11, 1936, eventually expanding to become the second-largest trolleybus fleet in the United States by 1952, boasting 463 units—outnumbered only by Chicago and closely rivaled by Atlanta.
Following 1963, the network was confined to a cluster of four routes originating from the Harvard bus tunnel at Harvard station, primarily serving the communities of Cambridge, Belmont, and Watertown. Control of the system transferred to the Massachusetts Bay Transportation Authority in 1964.
In 2004, the network extended with the introduction of the Silver Line (Waterfront), a bus rapid transit route utilizing dual-mode buses. These vehicles operated as trolleybuses within Boston’s Seaport District tunnel before switching to diesel power for surface travel. The Harvard-area trolleybus routes transitioned to diesel hybrid buses in 2022, followed by a similar conversion for the Silver Line in 2023.
History
The inaugural trackless trolley route in Boston was launched by the Boston Elevated Railway (BERy) on April 11, 1936, replacing an existing streetcar service. This initial crosstown line—later designated as route 77 and currently served by a bus—linked Harvard station with Lechmere station. Additional lines were introduced in 1937, and by 1942, the system had expanded to include 14 routes: ten converted from streetcar lines and four from motor bus services. In 1947, operation shifted from BERy to the public Metropolitan Transit Authority (MTA), which was subsequently succeeded by the Massachusetts Bay Transportation Authority (MBTA) in 1964—the current operator.
While originally a private entity under public oversight since 1918, BERy provided service across 13 municipalities within Greater Boston. The MTA expanded this coverage to include Revere. Beginning in 1958, following administrative changes, the MTA initiated a gradual replacement of trolleybuses with motorbuses. By 1963, only four trolleybus routes remained active, all centered around Cambridge. Trolleybus service returned to Boston proper with the launch of the Silver Line (Waterfront) in late 2004.
At its height, the trolleybus network comprised 37 routes predominantly serving Boston’s northern suburbs, alongside distinct operations in Dorchester and Arborway. Historically, a total of 44 trolleybus lines have existed—including the Silver Line trunk—as of 2022.
Table of former trolleybus routes
History
The trolleybus network centered around Harvard traces its origins to the Cambridge Railroad, a horse-drawn streetcar line inaugurated in 1856. Initial routes linked Harvard Square with Mount Auburn via Brattle Street and Porter Square, followed shortly by the establishment of the Watertown Horse Railroad in 1857. The Porter Square extension reached West Cambridge (present-day Arlington) by 1859, connecting with the West Cambridge Horse Railroad. By 1880, the Watertown line had extended service to Nonantum Square.
Electrification commenced on July 1, 1889, when the Harvard–Arlington route transitioned under the West End Street Railway. Electric streetcar operations between Watertown and Mount Auburn began in December 1893, with double tracks installed later in that decade. Due to resistance from local residents, electric streetcars were redirected from Brattle Street to Mount Auburn Street by 1894, accompanied by a parallel route along Concord and Huron Avenues.
Despite opposition to road widening, a branch serving Waverley Square in Belmont was introduced in 1898. Another extension to Belmont Center opened in 1906 but was discontinued in 1928 and never converted to trolleybus operation.
In 1938, trackless trolleys replaced streetcars on the Harvard–Aberdeen Avenue corridor (route 72). The Harvard–Arlington Heights line switched to diesel buses in 1955; however, streetcars continued limited runs between Harvard and North Cambridge. Beginning in 1957, trackless trolleys operated short-turn trips from Harvard to Benton Square along the Waverley route. On September 6, 1958, full conversion from streetcars to trolleybuses occurred on the Harvard–Watertown Square (71), Harvard–Waverley (73), and Harvard–North Cambridge (82/77A) lines.
These four routes remained operational long after most of the system had transitioned to diesel buses, partially due to efforts to minimize diesel vehicle presence within the Harvard bus tunnel. Originally opened for streetcars in 1912 and adapted for trolleybus use in 1938, this tunnel features separate upper and lower one-way levels. A comprehensive renovation between 1979 and 1985 aligned with the MBTA Red Line’s Northwest Extension project, incorporating new platforms and portals. Environmental advocacy during the 1970s also played a role in preserving these trolleybus lines.
Service reductions began with the elimination of most trips on route 77A by January 2005, leaving only non-revenue movements. In March 2013, route 72’s trolleybus service was replaced by diesel buses due to road construction and facility upgrades; although electric operations were intended to resume, route 72 was curtailed to peak-only service by December 2019 and fully suspended in December 2020.
In 2021, the MBTA announced plans to refurbish the North Cambridge Carhouse for battery-electric bus operations by 2023, marking the end of trolleybus service on all Harvard-based lines. As part of this transition, routes based at North Cambridge were relocated in 2022 to a non-electrified garage to allow uninterrupted reconstruction work. The final trolleybus services on routes 71 and 73 ceased on March 12, 2022. Beginning earlier that year, multiple utility and roadway projects prompted MBTA to permanently substitute diesel hybrid buses for trolleybuses on these corridors.
Vehicles
Within the westbound or lower tunnel, loading platforms are positioned on the left side. Consequently, trolleybuses serving this station were equipped with left-side doors in addition to the conventional right-side doors, enabling passengers to board without crossing traffic lanes. Diesel buses, however, do not have doors on the left side, which necessitates passengers crossing the roadway at the westbound stop. In 2004, the MBTA introduced new low-floor trolleybuses manufactured by Neoplan USA to replace the 1976 Flyer E800 models; these newer vehicles complied with Americans with Disabilities Act requirements (refer to MBTA accessibility).
Operations
Vehicles operating from Harvard were stored and maintained overnight at North Cambridge Carhouse, which serves as the northern endpoint for route 77A. Trackless trolley service was suspended on Sundays, with diesel buses covering those routes since 1963. To expedite boarding through left-side doors in the southbound Harvard tunnel, routes 71 and 73 permitted free outbound boarding, collecting fares upon exit.
Silver Line
The Silver Line consists of two distinct segments: a surface-level diesel-powered section along Washington Street and a Waterfront segment operating through a dedicated tunnel beneath the South Boston Waterfront. Due to ventilation limitations and restrictions against overhead wiring on interstate highways such as the Ted Williams Tunnel, dual-mode buses are utilized in the Waterfront section. These vehicles operate as trolleybuses within the tunnel and for a short distance on surface streets before switching to diesel power beyond Silver Line Way, then reverse direction for inbound trips. Motor buses are prohibited inside the Waterfront tunnel. Four routes run through the electrified tunnel: SL1 (Logan Airport), SL2 (Design Center), SL3 (Chelsea), and a shuttle service terminating at Silver Line Way.
Prior to February 2006, twelve standard-length Neoplan trackless trolleys temporarily served Silver Line operations until articulated dual-mode buses were fully deployed; these trolleys featured Silver Line’s silver livery over MBTA’s traditional yellow-and-white colors. At opening, only three out of 32 dual-mode buses were accepted; this number increased to 28 by February 2006. In late 2005 and early 2006, the twelve Neoplan trackless trolleys were reassigned to Harvard routes to replace remaining Flyer trolleybuses.
Following battery electric bus trials beginning in July 2019, MBTA placed an order for 45 articulated extended-range diesel hybrid buses in November 2020 to succeed the dual-mode fleet. These hybrids entered service in January 2023 and progressively replaced dual-mode vehicles. The final day of dual-mode bus operation and overhead wire usage occurred on June 30, 2023, marking the permanent discontinuation of Boston's trolleybus system—the first such closure in the United States since Chicago ended its trolleybus service in March 1973.
Fleet
Boston’s initial trolleybus fleet was manufactured by Pullman-Standard starting in 1936, with Boston Elevated primarily procuring Pullman vehicles until 1950. By 1952, Boston operated the largest Pullman-built trolleybus fleet in North America, totaling 438 units. Apart from a small series of five Twin Coach trolleybuses introduced in 1937 and twenty-five ACF-Brill units delivered in 1950, Pullman vehicles dominated until 1976. Route closures in 1964 led to retirement of older Pullmans and Twin Coaches, leaving only Pullman models from 1947–51 active.
Between 1976 and 1977, these were replaced by fifty Flyer E800 series trolleybuses (fleet numbers 4000–4049), with initial deliveries beginning in February 1976 and entry into service by April. The last Pullman vehicles were retired by August 1977. Flyers remained operational until 2006, with limited use continuing sporadically through March 2007; their final deployment occurred on December 21, 2007, performing ice-clearing duties.
Near the end of network operations in Cambridge and surrounding areas, a fleet of twenty-eight low-floor trolleybuses was introduced. Ordered in December 2000 alongside Silver Line vehicles, deliveries started in 2003 with full deployment completed by 2004. These units (numbers 4101–4128) were North America’s first low-floor trolleybuses, improving accessibility and operational effectiveness.
The Silver Line operated a fleet of thirty-two low-floor articulated dual-mode buses (numbers 1101–1132), manufactured by Neoplan USA with electrical components supplied by Škoda, delivered between 2004 and 2005. Eight buses (1125–1132), funded by Massport for Logan International Airport service (route SL1), were equipped with luggage racks and had fewer seats (38 compared to standard 47). In January 2011, four additional buses (1121–1124) received similar modifications to accommodate luggage racks.