The MBTA and the Massachusetts Department of Transportation (MassDOT) released the results of the Silver Line Extension Alternatives Analysis (SLXAA), which recommends extending Silver Line 3 (SL3) service from its current terminus in Chelsea to Sullivan Square Station on the Orange Line.

“Extending the SL3 to Sullivan Square will have a profound impact on thousands of riders, expanding access to our rapid transit system and a dozen more bus routes, amplifying more opportunities for jobs, education, and recreational activities,” said MBTA GM/CEO Phillip Eng. “We appreciate the efforts of the MBTA team and our partners at MassDOT for their work on the Silver Line Extension Alternatives Analysis and look forward to reviewing the upcoming design.”

MBTA’s SL3

Opening in 2018, the SL3 connects Chelsea with Logan Airport, East Boston, the Seaport District, and South Station, making quick, easy connections to many area bus routes, the Blue Line, the Red Line, and the Commuter Rail.

The SLXAA’s recommended extension to Sullivan Square would continue SL3 service through Everett and into Boston, connecting Chelsea directly with the Orange Line and a dozen more MBTA bus routes.

Approximately 80% of the six-mile-long extension through Chelsea, Everett, and Boston includes exclusive bus-only lanes, with the SL3 serving eight new stations. Bus routes that already operate in these areas would also have the added benefit of operating within these dedicated bus-only lanes for faster travel times outside of mixed traffic.

By extending SL3 service to Sullivan Square, Chelsea, and Everett, residents will benefit from increased service frequency outside of traditional morning and evening peak commuting hours and expanded access to 345,000 jobs via a 45-minute transit commute. Extending the SL3 is projected to increase daily SL3 ridership by over 15,000 riders.

The SLXAA also included an analysis of extending the SL3 beyond the Orange Line to Kendall Square or downtown Boston, ultimately determining further study is required. Extending the SL3 to these locations would also require the MBTA to further expand its Silver Line vehicle fleet and maintenance facilities.

In the near-term, the MBTA’s Bus Network Redesign team plans to implement high-frequency bus service from Chelsea to the Orange Line and from Sullivan Square to Kendall Square, creating multiple new connections in service.

Next Steps

The MBTA and MassDOT partnered with area municipalities to determine the potential alternatives and benefits of extending the SL3, and the SLXAA follows previous recommendations by the Lower Mystic Regional Working Group and the Everett Transit Action Plan.

Following the release of the SLXAA, the MBTA and MassDOT are exploring funding opportunities to advance the SLX design and engineering phase.

The preliminary cost to extend the SL3, including all associated roadway reconstruction, is anticipated to be approximately $95 million.