The preliminary engineering phase was completed at the end of 2009. This project is an extension of the MUNI Third Street Light Rail Project, which was completed in 2007. It involves a new MUNI tunnel line connecting the existing Caltrain Station at 4th and Townsend all the way into Chinatown. The project includes four new stations: 4th/Brannan, Moscone, Union/Market, and Chinatown.