Background 

The second phase of the Third Street Light Rail Project will extend service north from King Street along Fourth Street entering a tunnel north of Harrison Street, crossing beneath Market Street, and running under Stockton Street to Stockton and Clay Streets. A surface station will be provided near Bryant Street, and underground stations will be located at Moscone Center, Union Square, and near Clay Street in Chinatown. This alignment represents slight modifications to the locally preferred alternative adopted by the Board of Supervisors in June 2005, in that the subway portal was shifted two blocks north and the surface station was added. The changes were the result of recommendations arising from cost reduction workshops conducted in late 2005. Other changes resulting from the workshops include shifting the Union Square station south, closer to Market St., to facilitate a connection to the existing Powell St. station, utilizing two tunnel boring machines instead of one to reduce the construction duration by two years, and building shorter stations.

As 2006 came to a close, Preliminary Engineering for the Central Subway was 36% complete, and the project team continued developing various aspects of tunnel and stations design. Work was also proceeding with the supplemental environmental work in support of the new Locally Preferred Alternative (LPA). In parallel, the design team continued to conduct outreach meetings to share with the public the main project concepts. The primary funding source for the New Central Subway is anticipated to be Federal New Rail Starts dollars. In 2005, the project received a "medium-high" rating by the Federal Transit Administration.

To date, the project has received $16.8 million in Prop K funds and $45 million in federal funds.