ANTIOCH -- Highway 4 drivers can expect some road closures next week as traffic is shifted to a recently constructed road bridge at Somersville Road.

Westbound traffic will be shifted onto the new bridge over several nights next week, forcing closures to all westbound lanes and several ramps in the area, according to a Caltrans news release.

All westbound lanes between Lone Tree Way and Somersville will be closed from 12:01 to 3 a.m. Friday, Aug. 17 and 1 to 5 a.m. Saturday, Aug. 18, along with on ramps at Contra Loma Boulevard and Lone Tree Way.

Once all the traffic on Highway 4 is shifted to the new lanes, work will begin on a new eastbound bridge.

Eastbound traffic will be temporarily shifted to the new westbound bridge, meaning there will be two eastbound and two westbound lanes on it, Caltrans said.

While the detour is in place, the old eastbound bridge will be demolished and construction will begin on bridges for the new eastbound lanes and eBART.

Other closures next week include all eastbound lanes at Loveridge Road in Pittsburg from 12:30 to 5:30 a.m. Tuesday to Friday. The eastbound on-ramp from southbound Loveridge will be closed from 10 p.m. to 6 a.m. Monday to Thursday, and northbound from 6 to 11 a.m. Monday to Friday.

Updated road closure information is available at http://widensr4.org.