Silver Line (MBTA)

MBTA Silver Line

200px
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
Chief executive	Beverly A. Scott
Website	MBTA Silver Line

Silver Line route diagram
Legend
SL3 City Point (closed 2009) SL3 East 1st Street and M Street (closed 2009) SL3 Summer Street & Power House Street (closed 2009) SL2 88 Black Falcon Avenue SL2 25 Dry Dock Avenue SL2 Design Center SL2/3 21 Dry Dock Avenue SL2/3 Northern Avenue & Tide Street SL2/3 Northern Avenue & Harbor Street SL2/3 306 Northern Avenue Newburyport/Rockport Line SL6 Chelsea (opening 2017) SL6 Bellingham Square (opening 2017) SL6 Box District (opening 2017) SL6 Eastern Avenue (opening 2017) Chelsea Creek | Chelsea Street Bridge SL6 Airport (starting 2017) SL1 Airport Terminal B East SL1 Airport Terminal C SL1 Airport Terminal B West SL1 Airport Terminal E SL1 Airport Terminal A Boston Harbor | Ted Williams Tunnel SL1/2/3/6 Silver Line Way SL1/2/3/6 World Trade Center SL1/2/3/6 Courthouse Orange Line Green Line SL5 Park Street | Downtown Crossing SL5 Boylston Green Line SL1/2/3/4/6 South Station Red Line Commuter Rail and Amtrak SL4/5 Chinatown SL4/5 Tufts Medical Center Orange Line SL4/5 Herald Street SL4/5 East Berkeley Street SL4/5 Union Park Street SL4/5 Newton Street SL4/5 Worcester Square SL4/5 Massachusetts Avenue SL4/5 Lenox Street SL4/5 Melnea Cass Boulevard SL4/5 Dudley Square

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, 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.

Service routes

File:MBTA Silver Line map.svg

Schematic of Silver Line service

Waterfront: SL1 and SL2

File:Silver Line (MBTA) 1297.jpg

Dual-mode bus departing South Station to serve the SL2 Waterfront Line.

Two Silver Line services operate in a dedicated tunnel from South Station to Boston World Trade Center, then in a reserved surface right-of-way for another two blocks farther east to Silver Line Way station and beyond there in mixed traffic:

• SL1 Logan Airport – South Station
• SL2 Design Center – South Station

During rush hours, a few additional buses turn around at Silver Line Way and head back into the tunnel to augment the service between South Station and Silver Line Way.

SL1 buses operate in a loop at Logan Airport and only serve the terminal buildings (A, B1, B2, C, E), stopping at the arrivals level. Other free shuttle bus services connect the terminals with other airport destinations, including the Blue Line's Airport station, hotels, the rental car center, and the water taxi dock. A system of moving walkways connects Terminals A and E, the Hilton Hotel, and the central parking area. See the Logan Airport article for lists of which airlines serve each terminal.

Fares

Passengers traveling on SL1 and SL2 pay the standard MBTA subway fare: $2.10 when using a CharlieCard, $2.65 when using CharlieTickets or cash. Ticket vending machines that accept cash and credit cards are installed in the Logan Airport terminals and World Trade Center, Courthouse and South Stations. A faregate-free and cost-free transfer to and from the Red Line is available at South Station for all SL1 and SL2 riders, but only CharlieCard users get free transfers to other bus lines and reduced fare on Express Bus. CharlieCard and CharlieTicket users, but not cash users also get a free transfer to SL4 service, at its terminus outside South Station at street level.

Passengers boarding at Logan Airport do not have to pay any fare as part of a program to speed up service by allowing passengers to board using all three sets of doors. This fare-free boarding began as a pilot program on June 6, 2012; Silver Line ridership both to and from the airport has increased while Blue Line ridership held steady, indicating that the program was increasing transit usage at the airport. Massport reimburses the MBTA for all lost fare revenue, subject to FAA approval (as airport revenue cannot normally be used for outside projects).

Rolling stock

From South Station to Silver Line Way the Neoplan USA AN460LF dual-mode 60 foot articulated buses on these services operate as trolleybuses, powered by overhead electrical wire, to avoid generating internal combustion fumes in the tunnel, and continue on thereafter on diesel power, which is converted to electrical power to run the same electric motors used when running on overhead power. These buses provide higher capacity than standard 40-foot buses. Both the rear and center wheels are powered by electric motors, which permits these buses to continue operation even through snow.

These buses are wheelchair ramp–equipped, using kneeling bus technology and a flip-out ramp. (See MBTA accessibility for more information.)

Station listing

File:MBTA Courthouse Station.jpg

Courthouse Station

Dual-mode bus operating in electric mode on the Silver Line Waterfront.

Neighborhood	Station	Routes	Opened	Transfers and notes
Downtown Boston	South Station	SL1 and SL2	December 17, 2004	Red Line, Silver Line SL4, MBTA Commuter Rail, Amtrak, local and intercity buses
South Boston	Courthouse	SL1 and SL2	December 17, 2004	John Joseph Moakley United States Courthouse
South Boston	World Trade Center	SL1 and SL2	December 17, 2004	Boston Convention and Exhibition Center, seasonal ferry to Provincetown, Institute of Contemporary Art, Lenticular art on the lobby level of the station
South Boston	Silver Line Way	SL1 and SL2	December 17, 2004	Changeover between diesel and overhead electric power takes place here
East Boston	Logan Airport Terminal A	SL1	June 1, 2005	Massport and rental car shuttle buses; walkway to central parking and Hilton Hotel
East Boston	Logan Airport Terminal B south	SL1	June 1, 2005	See: Logan Airport for airlines and destinations at each terminal.
East Boston	Logan Airport Terminal B north	SL1	June 1, 2005
East Boston	Logan Airport Terminal C	SL1	June 1, 2005
East Boston	Logan Airport Terminal E	SL1	June 1, 2005	International arrivals, Hilton Hotel
South Boston	Seaport Hotel	SL1	N/A	World Trade Center, Boston Convention and Exhibition Center, transfer to SL2, next stop Silver Line Way
South Boston	306 Northern Avenue	SL2	N/A
South Boston	Northern Avenue & Harbor Street	SL2	December 31, 2004
South Boston	Northern Avenue & Tide Street	SL2	December 31, 2004
South Boston	21 Dry Dock Avenue	SL2	N/A
South Boston	25 Dry Dock Avenue	SL2	December 31, 2004
South Boston	88 Black Falcon Avenue	SL2	December 31, 2004	Cruise ship terminal
South Boston	Design Center	SL2	December 31, 2004

Washington Street: SL4 and SL5

File:Silver Line bus stop.jpg

Silver line bus shelter on Washington Street.

Two Silver Line services run between Dudley Square in Roxbury and downtown Boston along Washington Street in reserved bus lanes:

• SL4 Dudley Square – South Station
• SL5 Dudley Square – Downtown Crossing

These two services share most of their route from Dudley Square to Chinatown; SL5 continues northward to Downtown Crossing and Boylston stations, whereas SL4 heads east on Essex Street to South Station. Passengers can transfer to SL1 and SL2 buses at South Station; however, SL4 buses stop at a surface bus stop across the street from the station complex, whereas SL1 and SL2 buses stop at an underground stop within the station, so there is no direct transfer or capability for through service.

Fares

Passengers traveling on SL4 and SL5 pay the standard MBTA bus fare: $1.60 when using a CharlieCard, $2.10 when using a CharlieTicket or cash. At select stations, passengers can transfer from the Silver Line to the subway (Red, Green and Orange Lines) for an additional 50 cents when using a CharlieCard. At these same stations, passengers may transfer from the subway to the Silver Line for free.

Rolling stock

During the day, compressed natural gas (CNG) powered 60-foot Neoplan USA and diesel-electric hybrid New Flyer articulated buses are used on the SL4 and SL5 services for greater capacity than that provided by standard buses. At night, when the passenger load is less and the greater engine noise of the articulated buses is deemed more objectionable, standard (40-foot, non-articulated) CNG powered buses are used. During snowstorms, standard buses and sometimes a few articulated dual-mode buses from lines SL1 and SL2 (see above) are also used, because the articulated buses normally used on lines SL4 and SL5 have drivetrains only from the engine to the rear wheels and therefore do not work well on slippery roads (this is especially true for the Neoplan USA articulated buses, which are pulled from service even in case of light snow). The reverse substition is not allowed: for safety reasons, CNG vehicles are not allowed into the SL1/SL2 tunnel.

As with SL1 and SL2, these buses are wheelchair ramp-equipped, using kneeling bus technology and a flip-out ramp. (See MBTA accessibility for more information.)

Station listing

Neighborhood	Station	Routes	Transit Time	Opened	Transfers and notes
Roxbury	Dudley Square	SL4 and SL5	0 minutes	July 20, 2002	1, 8, 14, 15, 19, 23, 25, 28, 41, 42, 44, 45, 47, 66, 170, and 171 bus lines
Roxbury	Melnea Cass Boulevard	SL4 and SL5		July 20, 2002
Roxbury	Lenox Street	SL4 and SL5		July 20, 2002
Roxbury	Massachusetts Avenue	SL4 and SL5		July 20, 2002	1 and CT1 (Not the same as Massachusetts Avenue station on Orange Line, 1/2 mile northwest)
Roxbury	Worcester Square	SL4 and SL5		Late 2002
Roxbury	Newton Street	SL4 and SL5		July 20, 2002
Roxbury	Union Park Street	SL4 and SL5		July 20, 2002
Roxbury	East Berkeley Street	SL4 and SL5	10 to 12 minutes	July 20, 2002	9, 11 (inbound buses only)
Roxbury	Herald Street	SL4 and SL5		July 20, 2002	9 (outbound buses only)
Chinatown	Tufts Medical Center	SL4 and SL5		July 20, 2002	11, 43 and Orange Line
Chinatown	Chinatown	SL4 and SL5		July 20, 2002	11 and Orange Line (inbound buses only)
Downtown Boston	Boylston	SL5		July 20, 2002	43, 55 and Green Line (outbound buses only)
Downtown Crossing	Downtown Crossing	SL5	16 to 21 minutes	July 20, 2002	Orange Line and Red Line at Downtown Crossing; Green Line at Park Street
Downtown Boston	South Station	SL4	13 to 22 minutes	Oct. 13, 2009	Silver Line SL1 (Logan Airport), SL2, Red Line, MBTA commuter rail, Amtrak, local and intercity buses

History

Subway and streetcar proposals

In 1948 a state study, Surging Cities, made proposals for transportation in Boston. It had four proposals and the second part proposed that the Washington Street Elevated (operational, 1901–1987) elevated train line be replaced by a subway line for the length of Washington Street through Dudley Square to the line's terminus at Forest Hills. While $19,000,000 was initially budgeted, the subway part of the four proposals was shelved. Prior to the Elevated's removal, area residents petitioned to retain the line until a promised light-rail vehicle line could be established. Light-rail proposals generally envisioned extending the Green Line by reopening the southern part of the Tremont Street Tunnel (operational from 1897 to 1961) and extending surface light-rail trackage along Washington Street to Dudley Square. After the elevated line was scrapped in 1987, the MBTA withdrew its streetcar promise.

Silver Line development

File:Silver Line.jpg

Silver Line service plans as of 2005, showing the SL3 (discontinued in 2009) and the SL4 (never implemented)

The collection of services under the Silver Line umbrella have varying origins. The first section opened, known as Silver Line Phase I, was the line along Washington Street now referred to as SL5; it is the product of community demands for restoration of local service after the Washington Street Elevated portion of the Orange Line was demolished in 1987. Proposals to build a new subway line under Washington Street or a new trolley line along Washington Street were deemed impractical, so the Orange Line was re-routed about 1/2 mile west onto the Southwest Corridor right-of-way, leaving many local residents without a rapid-transit option. BRT was chosen to provide this service, and the MBTA feels it meets the needs of the communities affected by the Orange Line relocation. The line started running July 20, 2002, replacing service provided by the 49 bus (which had existed as a feeder route before 1987).

File:Outbound MBTA Silver Line buses at Courthouse station.jpg

A Silver Line trolleybus at Courthouse station. This 40-foot model was used in the early days of the service, but has since been transferred to the MBTA's Bennett division.

The tunneled section extending east of South Station, known as Silver Line Phase II, was constructed in conjunction with Boston's Big Dig and was originally referred to as the South Boston Piers Transitway. Tunnel sections were fabricated in a nearby, World War II–era dry dock and floated into place. Phase II opened on Friday, December 17, 2004, with the first route (Silver Line Waterfront) running only to Silver Line Way, temporarily using new electric trolley buses borrowed from the trackless trolley routes that have their hub in Cambridge, as not enough dual-mode buses were available initially.

When dual-mode buses were placed in service on December 31, 2004, two routes, dubbed SL2 and SL3, began service. As still not enough dual-mode buses were available, some rush-hour service was provided by CNG buses, with transfers at Silver Line Way. Through service was suspended after January 5, 2005, and was not brought back until March 5, with all buses dual-mode starting on March 14. Beginning on March 26, late night and weekend trips ran combined, running both around the BMIP loop and to City Point. The SL3 service ran to City Point via the Boston Marine Industrial Park; however, its ridership was low due to competition from the parallel 7 bus. The 7 is frequent (with 6-minute headways during rush hour), cost less and runs to Downtown Crossing rather than just to South Station. SL3 service was canceled in March 2009.

SL1 service to Logan Airport began on an interim basis on January 2, 2005. CNG buses ran on a Sunday-only (4 pm–10 pm only) shuttle route between Silver Line Way and the airport terminals. The agreement with the Massachusetts Department of Environmental Protection had called for airport service by January, but the MBTA did not yet have enough dual-mode buses for full service. Full-time SL1 service began on June 1, 2005.

An SL4 route from South Station to Andrew station via the Boston Convention and Exhibition Center and D Street was planned to open in 2005, but was not implemented. The SL4 designation was used for another route in 2009:

File:SouthStationSL4shelter.agr.jpg

Stop at South Station for the SL4 bus service that connects the two halves of the Silver Line. Service began October 13, 2009. South Station is in the background, across Atlantic Avenue. Note the red "bus only" lane on Essex Street, in front of the bus shelter.

For nearly five years after the opening of Silver Line Phase II, the two segments of the Silver Line were disconnected from one another. The MBTA wanted to connect the two via an underground tunnel, however the construction of this section, dubbed Silver Line Phase III, is no longer included in the region's long term plan due to funding concerns. A partial solution that did not require a new tunnel opened on October 13, 2009, after fast-track construction using federal stimulus money. The new route, SL4, covers much of the same ground as the proposed Phase III in a dedicated bus lane on the surface that terminates across Atlantic Avenue from South Station, allowing a somewhat circuitous pedestrian transfer between Phase I and Phase II. When SL4 began operation, the existing Silver Line Washington Street service was rebranded SL5.

Route numbering

The Silver Line's four branches are known by their call numbers: SL1, SL2, SL4, and SL5. In addition to the public numbering system, the MBTA's rapid transit lines, including the Silver Line, have numbered designators for different services. The use of these designators dates back to the numbered streetcar lines of the early 20th century. Unlike the regular bus routes, however, the numbers for rapid transit services are only used internally for operations purposes. The SL5 is known as the 749 after the 49 bus it replaced, while the other routes have similar numbers:

Route	#	Notes
SL1	741
SL2	742
SL3	743	Discontinued in 2009
Shuttle	746	South Station—Silver Line Way
SL4	751
SL5	749

Ridership and service cost

The Silver Line services are among the most high utilized and least costly bus routes in the MBTA system. Three of the services—SL1, SL5, and the South Station to Silver Line Way shuttle—are the only bus routes that show a net profit. The median net cost among the 173 MBTA bus routes in 2012 was $2.13 per passenger.

Silver Line ridership and costs,
mid-2012

	SL1	SL2	SL4	SL5	Shuttle
Daily ridership	8,388	5,214	5,799	15,472	2,594
Ridership rank	10	21	19	1	52
Net profit/ passenger	$0.07	$-0.30	$-0.58	$0.03	$0.17
Profitability rank	2	4	6	3	1

Total daily ridership for all Silver Line routes was 37,467 in mid-2012.

Future development

Extension to Chelsea

Map of the planned Silver Line Gateway route to Mystic Mall in Chelsea

The MBTA and MassDOT are building a new Silver Line route to Chelsea via East Boston, the Silver Line Gateway project. An exclusive busway and four new Silver Line stations will be built in Chelsea—Eastern Avenue, Box District, Bellingham Square and Chelsea. A new $20 million Chelsea commuter rail station and transit hub will be constructed at the Chelsea station terminus of the new Silver Line route near the Mystic Mall, so that trains will no longer block Sixth Street. The new Silver Line and commuter rail stations will be fully handicapped accessible. The Silver Line extension and new commuter rail stop will be built in two phases. Construction is expected to begin in the Spring of 2015, with Phase I construction completed in December 2016 and Phase II in December 2017.

The new route, likely to receive the designation of SL6, will begin at South Station and run through the Waterfront Tunnel, along with the SL1 and SL2 routes, to Silver Line Way, continuing with the SL1 through the Ted Williams Tunnel. The new route would then diverge to meet the Blue Line at Airport Station, and follow the Coughlin Bypass Road (a half-mile commercial-use-only road which opened in 2012) to the Chelsea Street Bridge. After the bridge, it will run up the abandoned section of the Grand Junction Railroad right-of-way, with stops at Eastern Avenue, Box District (at the end of Highland Street), Bellingham Square (at the former Chelsea commuter rail station), and Chelsea (at Mystic Mall), next to the new Chelsea commuter rail station. There will be no direct service to the Logan Airport terminals, which already are served by the SL1 route. Passengers from Chelsea will be able to access the airport via Massport shuttle buses from Airport Station. In addition to serving Chelsea, the new line will provide Blue Line riders a direct connection to the waterfront area and South Station.

The replacement Washington Avenue bridge over the commuter rail line, which was scheduled for construction in 2014, will be modified to include sufficient clearance for two bus lanes. A $3 million, 0.75-mile (1.21 km) shared use path greenway will be constructed along the Grand Junction next to the busway from Eastern Avenue to Broadway, with possible future connection to the East Boston Greenway.

One potential issue with Chelsea service is the need to expand the MBTA's fleet of dual mode buses to accommodate the new route.

Studies

In 2013, MassDOT conducted a Silver Line Gateway study of the new route. Public meetings began in March 2013 and continued for the remainder of the year. The route was previously studied as a preliminary section of the Urban Ring, a more-comprehensive project which has been suspended for lack of funding. Three possible alignments were studied. All followed the same route from South Station to Chelsea, but diverged after crossing the bridge to Chelsea.

The first alignment was essentially the version that is being constructed. The second alignment would have followed the Grand Junction to just short of the commuter rail station, then diverged onto surface roads to Bellingham Square. The third alignment would have run entirely on surface streets, serving two stops on Central Avenue and four stops along a loop serving Chelsea station and the MGH Chelsea healthcare center.

In September 2013, the MBTA indicated that it would pursue the first alternative despite potential issues with bridge clearances and rebuilding Chelsea station.

On October 30, 2013, MassDOT announced $82.5 million in state funding for the new Silver Line route to Chelsea. The MassDOT Board of Directors awarded a $33,752,196 construction contract on September 17, 2014 to McCourt Construction Company for the first phase of the project. A 1.3-mile long dedicated BRT bus-way will be built from just west of the Mystic Mall to Eastern Avenue, with two 12-foot travel lanes and two 3-foot shoulders. The Washington Avenue Bridge over the Commuter Rail Tracks and the new Silver Line right-of-way will be replaced and a shared use path will be constructed parallel to the bus-way from Eastern Avenue Station to downtown Chelsea.

After completion of the first phase, the MBTA will solicit bids for a new Chelsea Commuter Rail Station at Mystic Mall and a fourth Silver Line station at the site of the old Commuter Rail station.

New Silver Line stations

Station	Transfers and notes	Status
Chelsea	Mystic Mall 112, 114 bus lines, Newburyport/Rockport commuter rail line	Phase 1, Rail Phase 2
Bellingham Square	Downtown Chelsea 111, 112, 114, 116, 117 bus lines	Phase 2
Box District		Phase 1
Eastern Avenue	112 bus line	Phase 1
Airport Station	Blue Line subway, shuttle to Logan International Airport	Existing

Note: The above Silver Line Gateway project phases are unrelated to the phases of the original Silver Line, including the suspended Phase III discussed below.

Silver Line Phase III (suspended)

File:Silver Line Phase III alternatives.svg

Silver Line Phase III alternatives as of 2008, showing the original 4 alignments from 2005 plus the 2006 Charles Street modified alignment. The preferred alternative at the time of the project's cancellation was the Charles Street modified alignment (pink) feeding into the core tunnel (lime green).

Even before the first sections were opened, the MBTA planned to connect the Washington Street and Waterfront sections with a downtown tunnel. This proposed Phase III would consist of an underground busway running from Washington Street to South Station via Boylston station on the Green Line. The tunnel would allow run-through service and remove buses from downtown traffic, as well as connecting the Green Line to South Station apart from crowded Park Street station. The core tunnel from Boylston to South Station via Chinatown was to run under Essex Street, while four possible routings under downtown streets were considered for the section connecting Boylston to Washington Street. Capital cost was originally estimated at around $780 million, depending on the route chosen for the southern section, with completion in 2013.

Response to the plan was mixed. Some residents were in favor of the tunnel since it would allow a faster one-seat ride from the South End and Roxbury to downtown and the Waterfront, with a direct fare-controlled connection to three of the subway lines. Others objected to the placement of a portal on busy streets, while others were opposed to the plan as it would cement use of the bus-based Silver Line to replace the Washington Street Elevated instead of the subway line that was originally promised.

The Boston Regional Metropolitan Planning Organization rated the project as "high priority" in its May 2003 Program for Mass Transportation, citing its high estimated ridership, low operating cost and service to environmental justice neighborhoods. However, in November 2003, the Phase III project received a "not recommended" rating from the Federal Transit Administration (FTA), which expressed skepticism that the MBTA's operating cost estimates were reliable. In August 2005, the MBTA put the Phase III project "on hold" in order to avoid a second such determination, and to build community consensus on a locally preferred routing.

In February 2006, State Transportation Secretary John Cogliano proposed a $94 million plan that would eliminate most of the tunneling and cost of the original proposal while still connecting the two phases of the service. Under Cogliano's plan, the Silver Line would run on the surface via Kneeland Street and Surface Road to a new tunnel portal on Essex Street near South Station. A fare-controlled shelter would be added at Downtown Crossing. The plan also included expansion of surface Silver Line service, with a new branch running from Copley Square into the Essex Street portal to provide a one-seat ride from the Back Bay area. The southern branch would be extended from Dudley to the Red Line stations at Mattapan via Blue Hill Avenue (replacing the #28 bus) and Ashmont via Washington Street (replacing the #23 bus), with additional connections to the Fairmount commuter rail line at the then-planned Blue Hill Avenue and Four Corners/Geneva Ave stations. The plan was popular with Bay Village residents who had been worried about the full-length tunnel, but attracted criticism because it would not substantially speed travel times to downtown.

A third plan was put forward in March 2006, with support from most transportation leaders including Cogliano. The plan involved a variation of the Charles Street tunnel alignment, with the portal moved south and west onto Tremont Street between Charles Street and Marginal Road. This "Charles Street Modified" (CSM) alignment remained the preferred alternative for the remainder of the project. Contra-flow dedicated bus lanes, already in place on Washington Street, were to be extended onto Marginal Road and Herald Street to allow buses to reach the portal from the surface section. By mid-2008, environmental review and preliminary engineering were expected to be completed by the end of the year, with federal funding sought in 2010 and construction lasting from 2011 to a 2016 opening.

By May 2009, the estimated price of the tunnel plan, dubbed the "Little Dig," had risen to $2.1 billion. The (FTA) assigned it a Medium Low overall rating, making it ineligible to move into the final design phase for federal New Starts funding. The Boston Region Metropolitan Planning Organization removed Phase III from the list of recommended projects in its long range plan because of funding limitations – a rapid turnaround from its "high priority" rating in 2003. In April 2010, the Massachusetts Department of Transportation (MassDOT), concluding that it could not successfully compete for more than one New Starts grant, informed the FTA that MassDOT was no longer seeking New Starts money for Phase III. All New Starts funds available would instead be directed to the legally mandated Green Line Extension project. In a July 2010 report to the Department of Environmental Protection, the MBTA declared that Phase III was on indefinite hold and no further funds would be spent on the project.

Other future corridors

File:Pleasant Street Branch.png

Southern branch of the Tremont Street Subway near the former Pleasant Street Portal. This tunnel was briefly considered for use in the Phase III tunnel and is the likely connecting route for a proposed conversion of the Washington Street section of the Silver Line to a branch of the Green Line.

Several other Bus Rapid Transit and express bus projects have been proposed in Boston, many under the Silver Line banner. The first two phases of the Urban Ring Project were to be BRT, with light or heavy rail for the final phase. The Urban Ring was considered a separate project, although it would have shared the SL1 route between Silver Line Way and Logan Airport. Like the Phase III tunnel, the Urban Ring is on long-term hold for financial reasons.

A number of Silver Line expansion corridors were considered in the 2003 Program for Mass Transportation (PMT); most were given brief consideration but not acted upon. One, a BRT express overlay for the #28 bus route (which runs from Ruggles Station to Mattapan via Dudley), was revived in 2006 as part of Phase III plans. In 2009, the state proposed to replace the 28 bus entirely with a BRT route called 28X, including the installation of dedicated bus lanes, bus signal priority, and on-platform fare collection. However, the application for federal stimulus funding was withdrawn due to local opposition, as the plan would have taken parking along Blue Hill Avenue and reduced the number of bus stops along the route in order to speed up service. This rejection, plus the 2009 failure of the SL3 City Point route (which had been rated a medium-priority and "very cost-effective" project in 2003), tempered remaining enthusiasm for BRT in Boston. (However, in 2012, the Roxbury-Dorcester-Mattapan Transit Needs Study recommended the 28X bus to be implemented with no new infrastructure as an express bus adding additional trips to the corridor.)

Several other corridors were considered in the 2003 PMT. These included a Dudley-Ashmont route replacing the #23 bus (also revived in 2006 in Phase III planning, but not during the 28X proposal), as well as a new BRT tunnel to Kenmore with surface branches to the Longwood Medical Area via Brookline Avenue and Allston via Commonwealth Avenue, the Mass Pike, and Cambridge Street. The City of Boston proposed an alternate western Silver Line branch using buses along the Mass Pike without a new tunnel, similar to existing express buses.

The 2003 PMT included the possibility of converting the Washington Street section of the Silver Line to light rail (as had originally been promised) using the abandoned southern section of the Tremont Street Subway. The project was estimated to cost $374 million; ridership was estimated to be 34,000 daily riders almost entirely diverted from the Silver Line service. The project was given low priority, with the Phase III tunnel recommended instead. In 2012, the Roxbury-Dorcester-Mattapan Transit Needs Study recommended the conversion to light rail as a long-term project, with the additional possibility of extending the line down Blue Hill Avenue to Mattapan along the #28 bus route.

Criticism

BRT quality

A comparative rating from the Institute for Transportation and Development Policy (ITDP) determined that the Boston Silver Line was best classified as "Not BRT" after local decision makers decided not to implement most BRT-specific features, such as enforced exclusive bus lanes, high level platforms, off-vehicle fare collection and sheltered, comfortable stations. The gradual erosion during the design process of features called for by the ITDP's international BRT Standard has been called "BRT creep".

Community groups in the Roxbury and South End neighborhoods, along with the Sierra Club, have presented findings that supported the criticisms. In addition, some groups have maintained that a light-rail line would be both cheaper and more effective than BRT, and that part of the tunnel required for this already exists.

There have been some improvements since the ITDP report. For example, the institution of free service from Logan Airport means that on-board fare collection occurs at only one stop (Silver Line Way) on the SL1 line. Also, the free service allows all-door boarding, reducing curb time spent waiting for luggage-carrying passengers to board or alight.

Route

The Silver Line's SL1 route from the World Trade Center stop to the Ted Williams Tunnel is considered by critics to be unnecessarily convoluted. Despite the fact that the Silver Line's portal is less than 100 yards (91 m) from the eventual entry ramp to the Williams Tunnel, the line must cross D Street at grade and proceed to the Silver Line Way stop to change over from overhead electric to diesel. This requires a loop back towards downtown on several surface streets before it can enter the tunnel, adding several minutes to the ride. The inbound route makes a stop above ground at the entrance to the World Trade Center stop, then proceeds eastwards to Silver Line Way and then goes underground for a second stop at the World Trade Center. For some time after the Big Dig ceiling collapse in 2006, the SL1 temporarily used a closer entrance ramp normally reserved for the Massachusetts State Police. However, use of this shortcut was stopped after the affected sections of roadway were reopened for Silver Line use.

Art and architecture

See also: Arts on the Line

The MBTA maintains an online catalog of the over 90 artworks installed along its six major transit lines. Each downloadable guide is illustrated with full-color photographs, titles, artists, locations, and descriptions of individual artworks.

See also

• BRT Standard
• Bus rapid transit creep
• Trolleybuses in Greater Boston

External links

• Silver Line—MBTA
• Boston Transit: The Silver Line—nycsubway.org
• A High-tech Keep Out—MBTA press release about security barriers at South Station tunnel
• Sierra Club report on Silver Line service