State Route 4 East Widening (Somersville Road to State Route 160)

The State Route 4 East corridor serves as the only major east-west transportation link joining the communities of Antioch, Pittsburg, Oakley and Brentwood with central Contra Costa County and the Bay Area. This corridor provides access to major industrial facilities (including refineries) in both northern and western Contra Costa County.

The project will widen State Route 4 East to eight lanes (three mixed flow lanes and one High Occupancy Vehicle (HOV) in each direction) from Somersville Road to Hillcrest Avenue including a wide median for transit, and to six lanes (three mixed flow in each direction) from Hillcrest Avenue to State Route 160.

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