The California Department of Transportation will start evaluating bids today for work on the Caldecott Tunnel improvement project, saying construction on the long-awaited fourth bore could begin by the end of the year.
The call for bids means the $420 million project is finally on a set schedule after years of discussion and delays, Caltrans spokesman Jeff Weiss said. The first public meeting on the fourth bore was held in 1992, he said. Construction is scheduled to start in December or January and completed in 2014, he said.
"This is one of those projects almost everyone wants," Weiss said. "Especially people living in central Contra Costa County who commute through the tunnel to the western cities of the Bay Area."
Right now, three bores, or tunnel shafts, run beneath the Berkeley Hills to connect Oakland and Contra Costa County via state Highway 24. The central bore alternates between serving westbound and eastbound traffic. Eight highway lanes narrow to six at the tunnel, a configuration that invites fender-benders, according to Weiss.
Adding a two-lane, 3,390-foot bore will "balance the freeway," he said, eliminating tunnel reversals and lane reductions.
However, much has changed in the area since 1964, when the tunnel's third bore was added to the original 1937 configuration.
"Now the Bay Area is quite crowded and it's much more difficult to build a large-scale transit project," he said.
In 2007, a consortium of community groups known as the Caldecott Fourth Bore Coalition sued Caltrans over environmental concerns related to tunnel construction. In the resulting settlement, the agency agreed to use low-sulfur diesel fuel for its heavy machinery and take extra measures to buffer nearby residents from excessive light and noise during construction.
Real-time noise monitoring for the project will be available online, Weiss said, a first for Caltrans.