Monday, September 25, 2017

SCVTA staff makes Phase 2 recommendations for BART extension

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The Santa Clara Valley Transportation Authority (SCVTA) Board will review staff recommendations at an October meeting regarding Phase II of the BART Silicon Valley Extension.

The six-mile, four-station extension from the Berryessa BART station into downtown San Jose and the city of Santa Clara, Calif., has been the subject of several workshops held to study the complexities of delivering the project.

SCVTA has been in project development for Phase II for almost two years. SCVTA has been considering station location options for the planned Downtown and Diridon stations, as well as two different tunneling methods.

Following environmental review and public feedback, SCVTA is recommending the station locations as Downtown West and Diridon North. SCVTA says a Downtown West Station would provide long-term revitalization of the downtown core and provides excellent transit connectivity to existing transit. Additionally, the transit authority says the Diridon North Station would maximize development potential in the area where there are great interest and growth.

The preferred tunnel option is a single-bore tunnel that would contain tracks for both directions in a 45-foot diameter tunnel versus two 20-foot diameter tunnels. Passenger boarding platforms, cross passages used for emergency passenger egress and other facilities would be constructed within the single-bore tunnel underground for all three underground stations. SCVTA says this tunnel configuration allows the construction work to be done out of the public right-of-way and without having to open up the street to do the excavation. This less disruptive, single-bore method would tunnel deeper underground, which would also avoid much of the risk associated with encountering unknown utilities

SCVTA, BART and consultant teams will return to the SCVTA Board on October 5 to bring back further feedback on the tunnel recommendation for the board to consider and approve. The board must then certify the environmental document by January 2018 to submit the project to the Federal Transit Administration to be considered for federal funding.