Green Line (MBTA) - Description

Description

The modern-day Green Line has its northern terminus at Lechmere station in eastern Cambridge. From there it runs south over the Lechmere Viaduct and into the Tremont Street Subway under downtown Boston, then west in the Boylston Street Subway to Kenmore. Collectively, the Green Line tunnels through Downtown Boston and the Back Bay are sometimes called the Central Subway in planning documents. Along the way, the "E" Branch splits just west of Copley station, running southwest through the Huntington Avenue Subway, eventually ramping up to the surface, continuing along Huntington Avenue, and terminating at Heath Street.

The "B", "C", and "D" Branches all diverge west of Kenmore. From south to north, the "D" Branch surfaces onto the grade-separated Highland Branch, a branch of the Boston and Albany Railroad until 1958, running to Riverside. The "C" Branch surfaces onto Beacon Street, running to Cleveland Circle, and the "B" Branch runs along Commonwealth Avenue to Boston College.

The "A" Branch ran to Watertown until 1969. Although the route-letter scheme had been introduced two years prior to its closure, the "A" designation was never signed on streetcars operating to Watertown. It was, however, included in the destination signs on the Boeing-Vertol LRVs ordered in the mid-1970s, when reopening the Watertown service was still under consideration. The A line tracks remained in non-revenue service to access maintenance facilities at Watertown until 1994.

The elevated tracks north of the Central Subway near North Station were closed from June 2004 until November 12, 2005 for replacement of the Causeway Street Elevated with a new tunnel under Causeway Street, still connecting to the Lechmere Viaduct. The historic concrete Viaduct across the Charles River remains in service, although it was closed for a number of months in 2011 to allow a complete rebuilding of Science Park station.

The original Tremont Street Subway south of Boylston station has been closed since 1962, and the streetcar lines feeding into it were replaced by bus service. The Pleasant Street Portal at its southern end has been covered over, but there were plans to build a new portal and reuse part of the tunnel for Phase III of the Silver Line bus rapid transit project. As of 2011, all Phase III tunnel construction plans are on indefinite hold due to lack of funding and heavy community opposition.