Drivers headed west through Antioch and Pittsburg on Highway 4 late Friday and early Saturday morning should prepare for delays, or find alternate routes.

Three separate closures of all westbound lanes of the freeway between Hillcrest Avenue in Antioch and Pittsburg's Railroad Avenue are planned from midnight to 5 a.m., according to the Caltrans news release.

Despite the overlapping closure hours, the three full closures will not occur concurrently, except for a very minor overlap during a transition from one closure to the next, Caltrans said.

Work between Contra Loma Boulevard/L Street and Railroad Avenue will be to restripe and shift the existing two lanes -- an initial step toward opening additional lanes.

Drivers will be detoured off Highway 4 and down city side streets to the next on-ramp.

For information on all Highway 4 closures, visit http://4eastcounty.org.

Contact Paul Burgarino at 925-779-7164. Follow him at Twitter.com/paulburgarino.