B Branch (MBTA)

B Branch (MBTA)
Name	B Branch
Type	Light rail
System	MBTA subway
Status	Operational
Locale	Boston, Massachusetts, U.S.
Start	Park Street
End	Boston College
Stations	22
Open	0 1896
Owner	Massachusetts Bay Transportation Authority
Operator	Massachusetts Bay Transportation Authority
Character	At-grade, grade-separated, and subway
Stock	Kinki Sharyo Type 7, Kinki Sharyo Type 8
Linelength	8.8 mi

B Branch (MBTA). The B Branch is one of the four surface-level branches of the MBTA Green Line, a light rail system serving the Greater Boston area. It operates from the downtown Park Street station through the Boston University campus area to its terminus at Boston College in the Brighton neighborhood. The branch is known for its street-running section along Commonwealth Avenue, which presents unique operational challenges and serves a dense residential and student population.

History

The line's origins trace back to the late 19th century with the opening of the Boston and Albany Railroad's Highland branch in 1886. This route was later electrified and converted for streetcar use by the Boston Elevated Railway, with service to Boston College beginning in 1900. The branch was integrated into the Green Line subway system following the construction of the Boylston Street subway and the later Kenmore Square portal. Major changes occurred in the 20th century, including the replacement of the Pleasant Street Incline with the current connection at Kenmore station. The Massachusetts Bay Transportation Authority assumed control in 1964, overseeing subsequent modernization efforts.

Route description

The B Branch begins in the Tremont Street subway alongside the other Green Line branches, sharing tracks from Park Street station through Boylston Street and the Arlington portal. It emerges to the surface at the Kenmore Square portal, entering the Kenmore station area. From there, it travels west on a dedicated, grade-separated right-of-way alongside the Massachusetts Turnpike before transitioning to street-running tracks in the median of Commonwealth Avenue. This at-grade section runs through the Allston neighborhood and the core of Boston University, featuring numerous grade crossings. The route concludes on a private right-of-way just west of Boston University leading to the terminal at Boston College.

Station list

The following stations are served from east to west. Stations from Park Street to Blandford Street are shared with other Green Line branches. * Park Street * Boylston * Arlington * Copley * Hynes Convention Center * Kenmore * Blandford Street * Boston University East * Boston University Central * Boston University West * Saint Paul Street * Pleasant Street * Babcock Street * Amory Street * Griggs Street * Allston Street * Warren Street * Washington Street * Sutherland Road * Chiswick Road * Chestnut Hill Avenue * South Street * Boston College

Rolling stock

Service is provided by Kinki Sharyo Type 7 and Kinki Sharyo Type 8 low-floor light rail vehicles. These vehicles are part of the standardized fleet used across the Green Line, maintained at the Riverside carhouse and the Southampton Street Yard. The Type 9 vehicles, part of a future fleet expansion, are also expected to operate on the branch. The street-running section of the B Branch imposes specific operational requirements on the rolling stock, including robust braking systems for frequent stops at grade crossings.

Operations

The B Branch operates as part of the Green Line's frequent surface service, with headways varying based on time of day. Due to the at-grade section on Commonwealth Avenue, it is the slowest of the four branches, with traffic signals and pedestrian crossings significantly impacting travel times. Operations are managed from the MBTA Operations Control Center. The branch interfaces with several MBTA bus routes, including the 57 bus which runs a parallel route along Commonwealth Avenue, and connects to the Framingham/Worcester Line at the Boston Landing station.

Future plans

Long-term proposals within the MBTA Capital Investment Program have included potential upgrades to the street-running section to improve speed and reliability, such as signal priority or dedicated lane improvements. Studies have also examined the feasibility of consolidating some station stops to reduce travel time. The branch is a key component of the Green Line Transformation project, which aims for overall system modernization. Future service patterns may be adjusted as part of regional transit plans developed by the Central Transportation Planning Staff.

Category:MBTA Green Line Category:Railway lines in Boston Category:Transportation in Brighton, Boston