In San Francisco, crews are busy digging caisson shafts as deep as 262 ft for the $325-million 181 Fremont, a combo office and residential tower next door to the massive Transbay Transit Center and office tower construction site. Several other large projects are within a stone’s throw in the neighborhood. “You can come in to work some days and see concrete trucks queuing up on the off ramp of the freeway because they have nowhere to go” due to the congestion, says Steve DeWees, project executive with Level 10 Construction of Sunnyvale. The firm is also the general contractor on another Bay Area office complex on the top starts list —the Facebook West Campus in Menlo Park.