Silver Line (Boston)

MBTA Silver Line

MBTA Neoplan AN460LF CNG (left) and AN460LF dual mode trackless trolley (right) on Silver Line duty.
Parent	Massachusetts Bay Transportation Authority
Founded	2002 (Washington Street) 2004 (Airport/Waterfront)
Headquarters	10 Park Plaza, Boston, MA 02116
Locale	Boston, Massachusetts
Service type	Bus rapid transit
Routes	4
Stations	13 (Washington St.) 9 (Airport/Waterfront) 5 (proposed)
Fleet	20 (Washington Street) 32 (Airport/Waterfront)
Daily ridership	33,386
Operator	MBTA
Website	MBTA Silver Line

The Silver Line is the bus rapid transit (BRT) system of the Massachusetts Bay Transportation Authority (MBTA). It currently operates four routes in two sections that were built in separate phases.

The first section has two routes from Dudley Square in Roxbury, mostly via Washington Street, to Boston's Downtown Crossing (SL5) and South Station (SL4), using articulated buses operating in reserved lanes. The second section runs from South Station Under to South Boston (SL2) and to Logan Airport in East Boston (SL1). It runs dual-mode buses, partly in a dedicated bus tunnel and partly on shared roadway, including surface streets, the Ted Williams Tunnel, and airport roads. Riders can transfer between the sections and to other lines at South Station; transfers there between SL1, SL2, and the Red Line—but not SL4—are within fare control. At South Station, however, a transfer from SL1, SL2, and the Red Line to SL4 (and vice versa) can be made by walking alongside streets.

Speed and schedule performance have disappointed some transit advocates and the Silver Line routes fall far short of the minimum BRT Standard promulgated by the Institute for Transportation and Development Policy (ITDP). Some sections have an exclusive right-of-way, but other sections are bogged down by street running in congested mixed traffic. As of September 2014^[update], a contract has been awarded for the first phase of an extension to Chelsea, Massachusetts, largely in reserved right-of-way; other extensions of the Silver Line are being studied as well.