Muni's newest light rail line, the T Third St. began service in 2007. Phase I runs from southeast SF along the Bayshore Corridor to the Caltrain (commuter rail) Depot (where it joins existing tracks to go downtown. See current route). Phase II will run from the Caltrain Station for several blocks and then enter a "new Central Subway" to cross under Market St. and continue to Chinatown. The $1.6 billion Phase II now appears to be fully funded, though legal obstacles remain. Opening date is set at 2019, the same year that electrification of the Caltrain line is expected to be completed.
"U.S. Secretary of Transportation Ray LaHood, Democratic Leader Nancy Pelosi, U.S. Senator Dianne Feinstein, Congresswoman Jackie Speier, Federal Transit Administration (FTA) Administrator Peter Rogoff, Board of Supervisors President David Chiu and other federal, state and local officials joined San Francisco Mayor Edwin Lee at a ceremony at the future site of the Central Subway's Union Square/Market Street Station to announce the approval of the New Starts funds.
The Central Subway's Full Funding Grant Agreement (FFGA) was approved by FTA Administrator Peter Rogoff on October 11."
Michael Cabanatuan, transportation reporter for the San Francisco Chronicle, writes that a "lawsuit, filed by subway critics Save Muni, is the latest, and so far most aggressive, effort to stall or kill construction of the 1.7-mile subway from Caltrain to Chinatown. The suit contends that the Municipal Transportation Agency's plans to build an entrance to the Union Square/Market Street station in the square violated a City Charter prohibition of nonrecreational uses in city parks."
The transit advocacy group prefers bus-based surface and 'shallow subway' alternatives to improve one of the most heavily used transit routes along Stockton St. into Chinatown. Electric trolley buses currently service this corridor.