Boylston Street subway
| Company type | Rail tunnel |
|---|---|
| Industry | Public transportation |
| Founded | 1914 |
| Headquarters | Boston , United States |
| Products | Rail transit tunnel for MBTA Green Line |
The Boylston Street subway is a rail tunnel situated mainly beneath Boylston Street in Boston, Massachusetts. Since its opening in 1914, it has served all four branches of the MBTA Green Line, running from Kenmore Square beneath the Back Bay area into downtown Boston, where it connects with the older Tremont Street subway. Initially, the tunnel terminated just east of Kenmore Square but was extended beneath the square to new portals at and in 1932.
History
In 1907, the Massachusetts General Court approved plans for what would become the Boylston Street subway, originally known as the Riverbank subway. The design was intended for rail vehicles and matched the specifications of the recently developed Cambridge Connection (Red Line).
The legislation entitled 'An Act to Provide for the Construction of an East and West Tunnel and Subway in the City of Boston' set forth a route beginning at Park Street station and ending near Massachusetts Avenue and Governor's Square.
Prior to construction commencing in 1911, new legislation modified the tunnel’s alignment to run beneath Boylston Street—a decision backed by the Boston Elevated Railway Co., then operating the city's rail system, due to perceived superior commercial opportunities.
Work on the tunnel began in 1912 within the Commonwealth Avenue median close to present-day Kenmore Square. By mid-1913, construction had advanced to Arlington Street amid ongoing discussions about extending the eastern terminus toward Post Office Square.
The Boston Transit Commission proposed a temporary connection linking the new tunnel with the existing Tremont Street subway for streetcar operations until a definitive plan was finalized. The General Court sanctioned this provisional connection without altering the officially designated endpoint.
By 1914, most streetcars on Boylston Street utilized this temporary link.
Merchants located between Boylston and Copley Square stations advocated for an additional stop to help restore customer foot traffic. Consequently, in 1915, legislation authorized an 'infill' station at Arlington Street despite opposition from transit officials.
A 1926 map from a regional planning agency suggested connecting Boylston Tunnel with the East Boston Tunnel, which had transitioned from streetcar to train service.
By 1932, the tunnel had been extended through Governor’s Square with new portals on Commonwealth and Beacon Streets. A pre-paid station was established at Kenmore Street designed to accommodate both trains and streetcars, promoting smooth transfers—a concept that remains relevant today.
Route
The tunnel's eastern terminus is located at the Tremont Street subway, just to the west of Boylston station, near the intersection of Boylston and Tremont Street adjacent to Boston Common. From there, it extends westward beneath Boylston Street. Arlington station is positioned at Arlington Street, while Copley station is found at Dartmouth Street within Copley Square. Just west of Copley, the Huntington Avenue subway diverges southward. The primary route proceeds west under Boylston; at Hereford Street, it turns northward into Hynes Convention Center station located at Massachusetts Avenue, then continues west beneath Newbury Street and crosses the Muddy River to reach Kenmore station in Kenmore Square.
The tunnel's depth fluctuates depending on the street and surrounding terrain. Stations such as Arlington, Hynes Convention Center, and Kenmore are situated significantly below street level and feature underground fare mezzanines that provide access to both platforms. In contrast, Copley station is positioned more shallowly, with fare gates located directly on the platform and lacking a free crossover. The tunnel reaches its greatest depth as it passes under the Muddy River within Boston's Fenway area.
See also
- Boylston Street Fishweir – archaeological discovery uncovered during excavation of the Boylston Street subway