A big-rig overturned on eastbound Highway 4 in Antioch Tuesday morning, blocking multiple lanes near the Contra Loma Boulevard exit and snarling the commute. The truck reportedly tipped over around 8:50 a.m., leaving the three left lanes impassable and forcing traffic onto local streets. Motorists faced delays for several hours as crews worked to clear the wreckage.
CHP posts live updates on lane status
The Contra Costa office of the California Highway Patrol posted traffic updates on X, first reporting the left three lanes blocked and later providing updates as crews cleared the scene. One of the agency’s posts is available on X via CHP Contra Costa on X.
**TRAFFIC UPDATE** SR-4 EB at Contra Loma: Number 3 & 4 lanes (right 2 lanes) are open. ETO is within 2hours. Follow for updates. Time of this post is 11:33 AM. pic.twitter.com/iS0GUIXJwk
— CHP Contra Costa (@CHP_ContraCosta) November 4, 2025
Why the closure snarled the commute
State Route 4 is a primary east–west artery for commuters in eastern Contra Costa County, so closures quickly back up traffic onto parallel streets and local off‑ramps. For live maps and detour information, Caltrans District 4 directs motorists to QuickMap and 511 for real‑time conditions.
Latest: lanes reopened by midday
All eastbound lanes were reported reopened around 12:30 p.m., and drivers had been urged to use alternate routes during the closure, according to CBS News Bay Area. Officials did not immediately say what caused the big‑rig to overturn.
How to avoid delays this afternoon
Motorists heading through Antioch this afternoon should allow extra travel time and check live traffic before they go. Check 511 or Caltrans QuickMap for updates and follow the CHP Contra Costa feed on X for the latest on the scene.
