San Francisco, California: Weekend Closures Shut Westbound I-80 and Highway 37 From Friday Night

Bay Area drivers face two full freeway closures this weekend, one in San Francisco and one in the North Bay, and both start on Friday night, October 23. KTVU reported the pair of closures on Friday, and Caltrans advisories confirm both sets of times and detours.

In San Francisco, Caltrans will close westbound Interstate 80, the Bayshore Freeway, from 5th Street to 15th Street from 11 p.m. on Friday, October 23, until 6 a.m. on Monday, October 26. Crews will place polyester concrete on the freeway deck. Caltrans said in its October 20 update that the work completes a broader I-80 Bayshore Freeway viaduct project that began on the eastbound lanes earlier this year.

How to get around the I-80 closure

During the San Francisco closure, drivers must use the Fifth Street exit, which Caltrans called the last exit before the closure. A detour map shows options to get back onto westbound I-80 or onto Interstate 280, and Caltrans posted more detour resources at sfhighwayprojects.com. KTVU reported that Caltrans strongly advises drivers to avoid using the Bay Bridge to enter the city and to use public transit or other bridges instead, including the San Mateo, Dumbarton and Richmond-San Rafael bridges.

Caltrans said the Central and Bayshore viaducts are 71 years old and carry thousands of vehicles a day near the Bay Bridge corridor. Doing the work now preserves the viaducts, improves ride quality and improves safety, the agency said.

Highway 37 closes for 55 hours in the North Bay

The second closure hits State Route 37 between Mare Island in Vallejo and Sears Point in Sonoma County. Caltrans will close both eastbound and westbound lanes from 10 p.m. on Friday, October 23, until 5 a.m. on Monday, October 26, a 55-hour closure. The work follows two westbound-only overnight closures on Wednesday, October 21, and Thursday, October 22, from 7 p.m. to 4 a.m. each night.

Crews will demolish the center median and install K-rail barriers to shift both eastbound and westbound traffic onto the westbound lanes. Once the shift is complete, crews will focus on the eastbound lanes to raise portions of the roadway by 3 feet to improve resilience and address flooding concerns, Caltrans said in its October 13 advisory. The agency described the work as emergency preparation for El Nino storms.

Caltrans spokesperson Bart Ney told KION that water stayed in Vallejo for much of the summer, damaging the roadway and cracking the pavement. He said the detour is about 40 miles and can add more than an hour.

For eastbound Highway 37, the detour sends drivers onto northbound State Route 121, then onto State Route 12 and State Route 29, before rejoining eastbound Highway 37. Westbound drivers use northbound State Route 29, then westbound State Route 12 and southbound State Route 121, past Sonoma Raceway. The City of Sonoma warned on October 20 that the closure will raise travel times and add traffic to alternate routes into Sonoma and Sonoma Valley. Caltrans said all work is weather dependent, and a second set of overnight closures on Highway 37 is scheduled from 10 p.m. on Friday, November 13, to 5 a.m. on Sunday, November 15.