Greycliff Road station

MBTA Green Line B branch
Company type	Public transit line
Industry	Public transportation
Founded	1896
Headquarters	Boston, United States
Area served	Boston, Massachusetts
Products	Light rail transit service

Adapted from the English Wikipedia article Greycliff Road station, available under CC BY-SA 4.0Updated 7 August 2025

The B branch, frequently referred to as the Commonwealth Avenue branch or the Boston College branch, constitutes a portion of the MBTA Green Line light rail network that operates along Commonwealth Avenue west of central Boston, Massachusetts. This line extends from Boston College station along the median strip of Commonwealth Avenue until it reaches , where it proceeds through the Blandford Street portal into Kenmore station. At Kenmore, it converges with the C and D branches, continuing onward via the Boylston Street subway and Tremont Street subway toward downtown Boston. Since October 2021, service on the B branch has ended at . Distinct from other Green Line branches, the B branch runs entirely within Boston’s city boundaries. The notable Green Line Rivalry between Boston College and Boston University takes its name from this line serving both institutions.

As of , operations maintain an 8-minute frequency during weekday peak periods, with intervals ranging from 8 to 12 minutes during off-peak times, deploying between 9 and 15 trains (equivalent to 18 to 30 light rail cars).

Early Development

The foundations of what is now the B branch trace back to the former Watertown Line and Beacon Street Line. In 1889, the West End Street Railway inaugurated the Beacon Street Line, which included a spur running from Coolidge Corner to Oak Square through Harvard Avenue, Brighton Avenue, Cambridge Street, and Washington Street. This route served the expanding suburbs of Allston and Brighton; however, a more direct alignment was sought.

During the mid-1890s, enhancements were made to Commonwealth Avenue between Governors Square and the intersection with Brighton Avenue, featuring a 33-foot-wide median specifically designed for streetcar operations to stimulate real estate growth. Service commenced on May 18, 1896, operating from Governors Square to Brighton Avenue and linking with existing tracks at . By June 13, 1896, the line had extended westward close to Nonantum Square.

Further westward development included constructing a 25-foot-wide streetcar median between and the Boston–Newton boundary at Lake Street. Service between Lake Street and downtown Boston began on August 15, 1896, with streetcars running along Chestnut Hill Avenue, the Beacon Street line, Washington Street, and Huntington Avenue. At Lake Street, this line connected with the Commonwealth Avenue Street Railway, which had reached Auburndale in March of that year.

Eastward from Governors Square, the Beacon Street line originally followed Beacon Street, then proceeded via Massachusetts Avenue and Boylston Street to reach Park Square. When Commonwealth Avenue segments opened, streetcars continued along heavily trafficked Tremont Street tracks—electrified since 1891—to access northern railroad terminals. Both Nonantum Square and Lake Street routes were eventually rerouted into the newly constructed Tremont Street subway, terminating at Park Street station shortly after its inauguration on September 1, 1897.

On October 1, 1897, the Boston Elevated Railway (BERy) assumed lease control over West End Street Railway, facilitating further expansion. Subsequently, on May 26, 1900, BERy unveiled new tracks along Commonwealth Avenue stretching from Chestnut Hill Avenue to Brighton Avenue. This development enabled direct service from Lake Street into downtown Boston via Commonwealth Avenue. Although Commonwealth Avenue in Brighton was sparsely developed at that time, this new corridor attracted substantial ridership. The majority of these tracks laid in 1900 were not positioned within a central median but instead occupied a reservation located between southbound traffic lanes and carriage lanes; notably, between and Wallingford Road, this reservation was considerably wider than typical track areas.

Expansion of service

On June 17, 1897, the Commonwealth Avenue Street Railway inaugurated the well-known Norumbega Park. This line later integrated into the Newton and Boston Street Railway (N&B) in 1904 and subsequently into the Middlesex and Boston Street Railway (M&B) by 1909. Starting January 17, 1903, through service connecting Norumbega Park with Park Street station commenced, with BERy operating east of Lake Street. The Newton Street Railway, which also merged into N&B in 1904, began through service between Park Street and via the Watertown Line on February 23, 1903. Following the April 1912 opening of the Cambridge Tunnel, Waltham-bound service was redirected to Central Square station in Cambridge. Additionally, on May 1, 1912, M&B launched a second through service over Commonwealth Avenue reaching Newton Highlands.

The Boylston Street subway extension opened October 3, 1914, lengthening the Tremont Street subway eastward past Governors Square with stops at Copley Square and Massachusetts Avenue. (The station was added in 1921.) Service on Lake Street via Washington Street was truncated to , except during peak hours. Through service to Newton Highlands was reduced to Lake Street, requiring transfers to BERy streetcars. Because older M&B streetcars could not match BERy subway speeds, Norumbega Park service continued using surface routes; this service divided at Lake Street starting November 1, with a connecting BERy line shortened to Kenmore–Park Street by November 21.

On November 21, rush-hour Washington Street service was cut back to Reservoir, leaving Chestnut Hill Avenue tracks used exclusively by Beacon Street cars. Beacon Street service was reduced to Reservoir on November 6, 1915, while Washington Street extended again to Lake Street. Beginning February 6, 1922, Washington Street operated as a shuttle between Brookline Village and Lake Street due to changes on the Huntington Avenue line. This shuttle transitioned to bus operation on April 24, 1926; it was rerouted to Brighton Center in June 1928 and ultimately became route 65.

Two prominent baseball venues were served by the Commonwealth Avenue line: Fenway Park, opened in 1912 near Governors Square, and Braves Field, which opened in Allston in 1915. In 1915, BERy introduced a prepayment surface station at Kenmore Street within Governors Square. Braves Field featured a loop track between Gaffney and Babcock Streets with a prepayment station that allowed streetcars direct entry into the ballpark. This loop also facilitated train turnarounds for Fenway Park games and rush-hour short-turn services; after November 1945, these short turns also operated midday and on Saturdays. The loop experienced heavy utilization during events; for instance, during the 1948 World Series, streetcars ran every 45 seconds between Park Street and Braves Field.

Subsequent modifications

Around 1916, BERy constructed a streetcar storage yard north of Commonwealth Avenue at Lake Street. By 1930, remaining M&B service to Lake Street was replaced by buses; that September, BERy enhanced the old transfer station by adding a new platform and waiting area within the yard. An expansion of Reservoir Yard completed in May 1940 supplemented Lake Street Yard operations and eliminated the necessity of housing some Commonwealth Avenue streetcars at Bennett Street Carhouse in Cambridge.

In June 1922, BERy proposed transforming the inner Commonwealth Avenue line into rapid transit using three-car center-entrance trains designed for greater capacity and reduced dwell times with headways as short as two minutes during peak periods. A terminal station near Linden Street close to Harvard Avenue was planned to facilitate transfers between subway trains and surface streetcars; however, local opposition led to abandonment of this proposal. Meanwhile, Lechmere Square station opened in East Cambridge that July.

Delays caused by congestion at Governors Square prompted state legislature action in 1924 directing plans for an expanded rapid transit network that included extending the Boylston Street Subway beneath Governors Square. A report issued in 1926 recommended reorganizing Boston’s streetcar tunnels into two rapid transit lines utilizing high-floor vehicles: one connecting East Boston to Brighton via a junction with the Tremont Street subway near Park Street; another extending the Boylston Street subway westward along Commonwealth Avenue with a new station under Governors Square. The plan included a transfer station at Warren Street near Brighton Center with intermediate surface stops along Commonwealth Avenue. It also called for removal of several busy grade crossings and anticipated future rapid transit expansion toward Lake Street due to growth in Brighton.

Estimated at $5 million (in 1926 dollars), construction of the Governors Square subway began after legislative revisions lowered BERy's rental expenses. Although a $1.4 million flyover ramp alternative was proposed by BERy and city officials, the tunnel option was ultimately selected. The new subway segment along with Kenmore station—branching out at portals on Saint Mary's Street (Beacon Street) and Blandford Street (Commonwealth Avenue)—opened on October 23, 1932. This extension laid groundwork for potential future conversion of Commonwealth Avenue line to rapid transit including additional underground development.

Interest in converting Commonwealth Avenue line fully to rapid transit diminished as priorities shifted toward expanding suburban subway lines. The Coolidge Commission reports from 1945 and 1947 advocated constructing a parallel rapid transit corridor along the Boston and Albany Railroad tracks while maintaining local streetcar operations on Commonwealth Avenue. Nonetheless, incremental improvements occurred: a siding opened at Washington Street in 1926 enabling short-turn operations; Beacon Street and Commonwealth Avenue lines extended to Lechmere in 1931 replacing shuttle services; a pocket track west of Blandford Street replaced an older crossover used for temporary storage; route number 62 was assigned around 1940 to the Lake Street line during systemwide renumbering; finally, on May 6, 1940, operations shifted from Bennett Street Carhouse near Harvard Square to Reservoir Carhouse reducing non-revenue moves along Cambridge Street.

Postwar period

During the early 1940s, the BERy initiated the replacement of its aging streetcars with PCC streetcar models, debuting them on the Lake Street route in May 1944 and completing the transition from center-entrance cars by December 10, 1945. Track modifications for the PCC vehicles involved refurbishing the short Chestnut Hill Avenue segment, which had been out of use since 1926, and establishing a connecting wye between Commonwealth Avenue and Chestnut Hill Avenue on May 31, 1947. Reflecting Boston College's growth, the BERy renamed the "Lake Street" line to "Boston College" on May 21, 1947. On August 29, 1947, the publicly owned Metropolitan Transit Authority (MTA) took over operations from the private BERy.

In January 1953, the rarely utilized siding at Washington Street was dismantled, leaving only a crossover in place. The Worcester Line stations between and were closed in April 1959 due to Massachusetts Turnpike Extension construction, resulting in the Watertown and Boston College lines becoming the exclusive rail transit options for Allston and Brighton. After acquiring Braves Field in 1953 following the Braves' relocation to Milwaukee, Boston University aimed to redevelop the loop area; consequently, the MTA decommissioned the loop on January 15, 1962.

In 1960, to create additional travel lanes, Commonwealth Avenue’s streetcar reservation between Warren Street and Wallingford Road was narrowed, with tracks repositioned into a median separating traffic lanes. On November 25, 1961, service on the Boston College line was truncated to Park Street station as the Riverside Line extended service to Lechmere. Between 1963 and 1965, reconstruction of the Commonwealth Avenue bridge over the Boston and Albany Railroad took place to accommodate the Turnpike Extension; during this period, streetcars operated via a temporary parallel bridge.

MBTA era

In August 1964, the Massachusetts Bay Transportation Authority (MBTA) succeeded the MTA. As part of a comprehensive system rebranding effort, all remaining streetcar routes serving the Tremont Street subway were unified under the Green Line designation on August 26, 1965. By 1967, branches were assigned letter designations: the Boston College line became known as the B branch; meanwhile, Watertown and Beacon Street lines were designated as A and C branches respectively. The MBTA tested various downtown terminal arrangements for Green Line branches; notably, in November 1964, B branch service was extended to a new loop at , marking its first regular use. Over more than twenty years, the B branch’s downtown endpoint shifted among Park Street, Government Center, , North Station, and Lechmere before settling at Government Center from 1983 until 2004.

On June 21, 1969, streetcar service east of Packard’s Corner was halved when the A branch was replaced by Watertown–Kenmore buses. In 1970, trackbed adjustments were made between Chestnut Hill Avenue and Lake Street; westbound lanes were lowered near Greycliff Road with corresponding stop relocations. Around 1975, University Road stop was eliminated and Alcorn Street stop shifted eastward to .

The downtown terminal extended to North Station on June 25, 2004 but reverted back to Government Center on January 1, 2005. It was further shortened to Park Street in March 2014 during Government Center renovations; Park Street remained as terminus after reopening in 2016. On October 24, 2021, B branch service was re-extended to Government Center ahead of the Green Line Extension launch to enhance Blue Line connectivity and balance downtown operations. From June 20 to July 1, 2022, B branch trains were replaced by buses for track maintenance and installation of a train protection system.

Stop consolidation and accessibility improvements

The deployment of low-floor light rail vehicles (LRVs) in 2000 marked the beginning of accessible Green Line service. In the early 2000s, the MBTA enhanced several surface stops by installing raised platforms as part of the Light Rail Accessibility Program. Around 2000, portable lifts were made available at and . Between 2002 and 2003, four surface stops—, Boston University Central, , and —were upgraded with raised platforms, with Boston College following suit in 2009.

The B branch has faced criticism for its slow pace, attributed to the high number of stops and frequent level crossings. Prior to 2004, it featured 22 surface stops, significantly more than other branches. In late 2003, the MBTA suggested removing five closely spaced stops with low ridership—Greycliff Road, , Mount Hood Road, Summit Avenue, and —to enhance travel times. After gathering public input, Chiswick Road was spared due to its proximity to housing for seniors. On April 20, 2004, the remaining four stops were closed on a trial basis; a subsequent survey revealed that 73% of riders supported these closures, which were then permanently enacted in March 2005.

In 2014, plans were unveiled by the MBTA to merge four non-accessible stops near Boston University's West Campus—, , , and —into two fully accessible stations as part of a Commonwealth Avenue reconstruction project. A contract valued at $17.8 million was awarded in March 2020. Construction took place from February 2021 through early 2022, necessitating bus replacements during much of 2021. The newly constructed stations, Babcock Street and , officially opened on November 15, 2021.

Track maintenance conducted during 2018–19 prompted accessibility enhancements at various stops. By December 2022, design progress for , , Chiswick Road, , and had reached approximately 30%. In March 2024, new designs proposed merging Chestnut Hill Avenue and South Street stations. Subsequently, in May 2024, the Federal Transit Administration granted $67 million to support accessible platform construction at fourteen B and C branch stops. Later that year, five additional stations were included: Blandford Street will be closed; Griggs Street rebuilt; Allston Street and Warren Street consolidated; and Boston College relocated. As of February 2025, the MBTA intends to issue a $74 million design-build contract by May 2025, with construction scheduled from fall 2025 through mid-2027.

In 2021, the MBTA revealed a long-term strategy involving replacing side platforms with broader island platforms at select or all surface stops. This extensive initiative encompasses station consolidation, upgrades, track realignment, and traction power improvements with an estimated cost of $221 million. Additionally, plans for a reconstruction and expansion of Lake Street Yard are underway to accommodate new Type 10 LRVs in the late 2020s.