The SFMTA's Board of Directors is expected to move forward with a contract for this project sometime in the next few months.

The scope of work for the project includes construction of three underground subway stations located at Union Square/Market Street, Chinatown and Yerba Buena Gardens/Moscone Center, a surface-level station at 4th and Brannan Streets and trackwork and systems from the 4th and Brannan Station to the Chinatown Station. Work on the project is planned to begin in the third quarter of 2013 and substantial completion is expected in the first quarter of 2018.

"We are very excited to be identified as the low bidder for construction of the next phase of San Francisco's Central Subway system," said Ronald Tutor, chairman and CEO of Tutor Perini.