Flatiron, as managing partner of a joint venture, was responsible for approximately $700 million worth of contracts in Phase 1 of the Exposition Light Rail Line project commissioned by the Exposition Metro Line Construction Authority. The project runs from downtown Los Angeles to Culver City, California.

The project consists of 9.6 miles of twin track light rail line, including construction of ballasted/imbedded track, passenger stations, a parking structure, cast-in-place bridges with elevated guideway, a cut and cover tunnel, traction and power and signaling and communications. Trains run at-grade along the majority of the alignment, with the exception of one under crossing at Figaro, and two elevated stations over La Brea Avenue and La Cienega Boulevard.

Flatiron crews often worked adjacent to busy streets and freeways, as the Expo Line parallels the heavily congested I-10 freeway. The new line is expected to cut travel time from downtown Los Angeles to Culver City to less than 30 minutes. Within two years of completion, ridership of 30,000 had surpassed the projected ridership of 27,000 by 2020.

Flatiron provided design review and constructability assessments during the design phase. Pre-construction activities began in early 2006, and construction began in early 2007. The project was open to passengers in April 2012. This is the sixth line in the Los Angeles County Metropolitan Transportation Authority rail system.