Ah the Silver Line, the often overlooked and sparsely ridden segment of the MBTA's rapid transit system. Not quite a bus and not quite a subway. What's the deal with this oddball of a transit system?
An extremely new system by Boston's standards, the Silver Line Phase 1 first opened in the summer of 2002. At that time it only ran from Dudley Square to Downtown Crossing and was created to meet the needs of residents displaced by the relocation of the Orange Line Elevated system (the El) that used to run along Washington Street. The system uses bus rapid transit (BRT) vehicles, which are dual-mode buses that run on electric power from an overhead line and are considered trackless trolleys when running in the underground tunnels from South Station to the Waterfront. They also run on diesel fuel while on the street.
Phase 2 of the Silver Line, originally called the South Boston Piers Transitway, opened in December of 2004, running from South Station to Silver Line Way. In January of 2005, service to Logan Airport began. The Dudley Sq.-to-Downtown Crossing and South Station-to-Logan portions remained unconnected for nearly five years until October of 2009, when the Patrick-Murray administration announced that the new service connecting the two routes was to open, running from Dudley directly to South Station and constructed using funds from the American Recovery and Reinvestment Act.
The picture of the map at right shows the newest version of the Silver Line service. I've found that the maps in most stations still don't show this newest connection and still say that the line ends at City Point on the Waterfront. The service to City Point (SL3) was shut down in 2008 after the MBTA found the ridership of that portion to be insufficient.
Today, according to the same press release announcing the construction of the Dudley-South Station connection, the Silver Line averages a daily ridership of 29,670.
There are four routes that the Silver Line follows. SL1 runs from South Station to the Airport terminals. SL2 runs from South Station to the Design Center on the Waterfront. SL4 runs from South Station to Dudley Square and SL5 runs from Boylston Street to Dudley Square.
A Phase 3 has been proposed to create a tunnel running below street level from South Station to Tremont Street to connect that station with the Boylston Street and Chinatown stops underground. The estimated cost for this project stands at around $780 million. According to A Better City, Phase 3 could relieve congestion on the core downtown stations and bring the 265,000 residents living on this line access to the 491,000 jobs located within walking distance of stations with two-seat ride access to the Airport. These numbers are expected to increase exponentially by 2030.
Despite many other benefits though, the project has been on hold since 2005, due to the enormous cost and scale of it and lack of consensus with neighborhood residents. It is currently listed as an "illustrative project," but has not received funding in the September 2009 amended version of the Long Range Transportation Plan put forth by the Boston Regional Metropolitan Planning Organization.
A study looking into expanding the line to Chelsea is currently underway.
So although it may not be as heavily ridden or widely known as its heavy and light-rail brethren, the Silver Line still plays a major role in the daily commutes of thousands of passengers.