SR 4 Bypass (Now State Route 4)

The State Route 4 Bypass project was developed through a cooperative effort among Contra Costa County and the Cities of Antioch, Brentwood and Oakley for the purpose of easing traffic congestion in Brentwood and Oakley, and to provide access to the growing areas of southeast Antioch and western Brentwood. In February 2012 Caltrans adopted the Bypass as its new State Route 4, replacing the segment of State Route 4 that passes through the downtowns of Oakley and Brentwood.

Segments 1 and 3 (Completed) [PDF - 216 KB]