The Silver Line is the Massachusetts Bay Transportation Authority's (MBTA's) sole Bus Rapid Transit Line, running from Dudley Square in Roxbury, Massachusetts to downtown Boston, Massachusetts, with planned extensions to South Boston and Logan Airport in East Boston.

The Silver Line is planned to be built in three phases; only phase I and part of phase II have been completed as of December, 2004.

Phase I

Phase I of the Silver Line runs between Dudley Square, Roxbury, and downtown Boston (with free transfer connection to the Green Line at Boylston and to the Orange Line at Downtown Crossing and Chinatown, although these connections are intended to be temporary).

Phase II

Phase II of the Silver Line instituted a separate tunnel from South Station to Boston's World Trade Center and 1/2 mile further east to Silver Line Way. (This section was originally referred to as the South Boston Piers Transitway.) This section opened on Friday, December 17, 2004.

When dual-mode buses are delivered in 2005, service will be extended on three new routes:

• To terminals of Logan Airport (via the Ted Williams Tunnel)
• To the Boston Convention Center and down "D" Street
• To the Marine Industrial Park

Today, service on the second and third lines is provided by two diesel bus lines designated SL-2 and SL-3; transfers are provided at the Wolrd Trade Center Silver Line station.

Phase III

Phase III comprises the connection of the two halves of the Silver Line via an underground busway from Boylston station on the Green Line to South Station. It has not been funded yet and is not expected to be completed until after 2010. At this time, three possible routings are being debated.

Future BRT options

In addition to the Silver Line, BRT is being considered as a means of implementing the Urban Ring Project and providing improved cross-town service.

Silver Line critiques

In MBTA nomenclature, BRT lines are named by colors, not by number. This system is intended to equate BRT lines with subway lines as equivalent services. There are historical reasons for this equation. The Silver Line is the result of a court order mandating restoration of local service after the Washington Street Elevated portion of the Orange Line was demolished and the Orange Line was re-routed onto the Southwest Corridor right-of-way. Proposals to build a new subway line under Washington Street or a new trolley line along Washington Street were deemed impractical (for the same reasons that the Orange Line was moved), which is why BRT was chosen as a solution.

Detractors of Silver Line service insist that BRT is still a bus, not a high-speed transit line, and provides equivalent quality and speed to other buses. Logically, it is therefore undeserving of the dignity of equality with Boston's subway lines. These groups sometimes refer to the Silver Line as the "#49 bus" (this being the bus line with an identical routing that the Silver Line replaced) and the "Silver Lie" (used because of concerns from groups that the MBTA has reneged on a promise of real rapid transit.)

Silver Line buses are wheelchair ramp equipped using a kneeling bus and a flip-out ramp. See MBTA accessibility.

External link: MBTA's allaboutsilverline.com (http://www.allaboutsilverline.com/)