Drivers crossing the Richmond-San Rafael Bridge face nightly lane closures starting Monday, Aug. 31, and running through Friday, Sept. 4.

Caltrans maintenance crews will shut down lanes on both decks of the I-580 bridge each night from 7 p.m. to 5 a.m., according to a Caltrans District 4 traffic advisory. The work is for bridge maintenance and repairs, though the agency did not specify the scope of the project.

The closures hit eastbound traffic harder. On the lower deck heading toward Richmond, two lanes will close, leaving one lane open. On the upper deck heading toward San Rafael, one lane will close, also leaving one open.

Caltrans advised motorists to expect delays and to allow extra travel time or seek alternate routes. The advisory did not name a specific detour. Freeway message signs will alert drivers approaching the work zone, and the agency urged motorists to reduce speed and watch for merging traffic near the closure areas.

The bridge connects San Rafael in Marin County with Richmond in Contra Costa County.

Cyclists and pedestrians who use the bridge's separated path should note it operates on a limited schedule. The path is open Thursdays at 2 p.m. through Sundays at 11 p.m., according to the Metropolitan Transportation Commission. On days when the path is closed, a free bike shuttle runs from a stop near 2186 Francisco Blvd. East in San Rafael. Shuttle hours are 6 a.m. to 8 p.m. Monday through Wednesday and 6 a.m. to 2 p.m. Thursday.

511 SF Bay, the Bay Area's traffic information service, posted a reminder of the closures on X on Sunday, Aug. 30.

Drivers can check real-time conditions at quickmap.dot.ca.gov or follow @511SFBAY on X for updates throughout the week.