Urban Ring Project (MBTA)

Transportation advocates in Boston have complained that rail transit riders cannot travel from one outlying area to another without first traveling to the downtown hub stations, changing lines, and traveling outbound again. Some of the radial transit lines, notably the Green Line, are so overcrowded that service is very slow and limited in capacity because of rush-hour "crush loads". There are several crosstown bus lines, such as the #1, #66, CT1, CT2, and CT3 routes, but they are slow, unreliable, and subject to bus bunching because they must operate in mixed street traffic.[4]

A circumferential rapid transit line was proposed by the City of Boston as early as 1923, and circumferential transit has been studied as early as 1972, in the Boston Transportation Planning Review.[5] Detailed proposals were not studied until the late 1990s.[6]

The proposed project has three phases. The first phase has been partially implemented. Phase 1, as it is commonly called, involves expanding "crosstown" bus lines serving the entire corridor and "express commuter" lines connecting to suburban locations. Phase 2 would create six overlapping Bus Rapid Transit lines forming a complete ring around downtown Boston. Phase 3 includes the implementation of rail service on the most heavily traveled portion of the ring, from Assembly Square in southeastern Somerville to Dudley Square in the Roxbury neighborhood of Boston, via East Cambridge.

Phase 1[7] as recommended in the Major Investment Study, would expand the "crosstown" (CT) bus system by extending and increasing frequency on the three existing lines, and by adding eight new lines. It also adds "express commuter" (EC) lines for connections to locations outside the corridor. Estimated ridership according to the Phase 2 DEIR would have been 40,000 for 2003, at a capital cost of $100 million, for low-floor, low-emissions buses.

The MBTA determined that Phase 1 of the Urban Ring project did not meet the threshold requirements for an extensive environmental review, and so can be implemented as a part of its normal service planning process. However, of the eleven CT routes and three EC routes proposed, only CT1, CT2, and CT3 were running as of 2014.[8]

Phase 3[13] would add a rail line on the most heavily traveled portion of the corridor, from Assembly Square in Somerville to Lechmere, Kendall Station, crossing Massachusetts Avenue near MIT, and connecting at Longwood Medical a, Ruggles, and Dudley Square. The exact alignment would be determined through further environmental review, and included possible stops in Union Square Somerville, Cambridgeport and/or Kenmore Square, and a possible new tunnel under the Charles River.

There were three alternatives being considered for Phase 3, which differed from the alternatives described in the Major Investment Study (MIS) and Draft Environmental Impact Review (DEIR). Employment growth projections have also changed since those documents were written. The three proposed options for what type of rail service to build were:

• A light rail branch of the Green Line, mostly on the surface
• A light rail branch of the Green Line, entirely subway
• A heavy rail branch of the Orange Line, entirely subway

Estimated ridership is 282,000–293,000 passengers per day in 2025; about 47,000 would be diverted from cars, and most of the rest would be diverted from trips on congested radial lines, reducing the need to travel through downtown Boston.

Since the suspension of the overall project, a segment of the original route was constructed, completing in 2018. The "Silver Line Gateway" service (route SL3) has commenced, connecting Downtown and South Boston to the inner-core city of Chelsea, with an intermediate stop serving Logan Airport. The route is a mix of dedicated right-of-way and shared street traffic segments, using articulated buses.

• Interstate 695 (Massachusetts) – a 1960s proposed but cancelled highway involving many of the same communities

• Massachusetts DoT Website for the Urban Ring Project
• Phase 2 plans
• GRAND JUNCTION FEASIBILITY REVIEW, December 22, 2016, City of Cambridge