Welcome to the Contra Costa Transportation Authority, a public agency formed by Contra Costa voters in 1988 to manage the county's transportation sales tax program and to do countywide transportation planning. The Authority is also the county's designated Congestion Management Agency, responsible for putting programs in place to keep traffic levels manageable.

    Projects

• [Caldecott Tunnel]
• [Route 4 Bypass]
• [e-BART]
• [SR 4 East]
• [I-680/SR 4 Interchange]
• [I-680/Norris Canyon HOV Ramp]
• [I-80 Central Avenue Interchange]
• [I-80 San Pablo Dam Road
     Interchange]
• [I-680 HOV Lane Gap Closure]
• [Other Ongoing Projects]
• [Measure J Projects]
• [Completed Projects]