Project Overview
The existing Caldecott Tunnel consists of two tunnels (or bores) constructed in 1937 and a third tunnel built in 1964. Each tunnel has two lanes which causes State Route 24 to reduce from eight lanes to six lanes through the Caldecott Tunnel. To maximize the capacity of the existing tunnel, the traffic direction in the center bore is reversed to accommodate peak direction demand. The construction of a fourth tunnel will help alleviate congestion and improve travel times along State Route 24.
Planning for this project began in summer 2004, when a joint Caltrans, Contra Costa Transportation Authority and consultant team was formed to prepare technical studies, the Project Report, and the Final Environmental Assessment/Environmental Impact Report. The Final EA/EIR, released in fall 2007, identified the Preferred Alternative for the project as a two-lane tunnel north of the existing tunnels. The team is currently in the process of developing the final roadway and tunnel design. Please visit the Environmental Analysis and the Project Design and view the project timeline pages for more information.
Project Location Click to Enlarge | Project Limits Click to Enlarge |
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