The McClure Tunnel, which connects the 10 Freeway to Pacific Coast Highway in Santa Monica, will be closed Friday night and into Saturday morning.
The closure will continue for seven hours, beginning at 10 p.m., so workers can perform maintenance, Caltrans announced. The 4th/5th Street onramp to the westbound 10 Freeway also will be closed, said Tim Weisberg of Caltrans.
Traffic heading west on the 10 Freeway to northbound PCH will be diverted to the 4th/5th Street offramp. Traffic traveling on southbound PCH to the eastbound 10 Freeway be diverted to Ocean Avenue.
The closures will enable crews to conduct a "swarm" maintenance operation that includes clearing drains, washing the tunnel, repairing guardrails and landscaping.
Signs alerting drivers of the closure will be posted. Drivers can check on closures and traffic conditions using Caltrans QuickMap at quickmap.dot.ca.gov or the free QuickMap app on Google Play or the App Store.