Thursday, December 07, 2017

SCVTA to continue analysis of tunnel options for BART extension

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SCVTA to continue analysis of tunnel options for BART extension SCVTA

The Santa Clara Valley Transportation Authority (SCVTA) has adjusted the project development timeline for the BART Silicon Valley Phase 2 extension in order to further evaluate tunneling options for the project.

In order to progress with state and federal environmental clearance, a defined project description is necessary. SCVTA staff originally identified a single-bore option to construct the five-mile subway portion of the extension as the viable option. However, a recent peer review panel, citing time constraints related to the current federal funding schedule coupled with the preference of BART, advised that a twin-bore tunnel would be the preferred option.

SCVTA says it is embracing the results of the peer review, but as the main reasoning behind preference of the twin-bore tunnel is based on time constraints, it is requesting an extension to the project development timeline by an estimated three months. The request was submitted to the Federal Transit Administration.

SCVTA says the timeline extension would allow it "to demonstrate more thoroughly how the single-bore configuration can satisfy BART's operational safety concerns in addition to further exploring construction impact mitigation strategies for the Downtown San José stations."

"As Santa Clara County's Transit Agency and Congestion Management Agency and as the owner and builder of the BART Silicon Valley Extension, [SCVTA] has a responsibility to fully explore options that will result in the safest and most efficient system being built with the least amount of impact on its customers, businesses and the community," the transit authority said.

The planned six-mile extension would extend BART from the Berryessa/North San José Station into downtown San Jose and then into the city of Santa Clara.