San Franciscans who venture out this weekend should brace for a traffic horror show, with drivers laying on their horns or obsessively checking their navigation apps.

Such chaos may be difficult to avoid as Caltrans officials plan to shut down the eastbound Interstate 80 Bayshore Freeway between 17th and Fourth streets, along with the northbound and southbound ramps to U.S. 101. The closure, necessary for workers to make ongoing repairs to the freeway’s viaducts, will begin at 11 p.m. Friday night, and last through 6 a.m. Monday. 

During that period, drivers heading from the South Bay toward the Bay Bridge will come to a halt after Hospital Curve and be forced to exit at Vermont Street. The line of cars will then snake through Potrero Hill and crawl into SoMa, bypassing 1.6 miles of freeway before re-entering at Fifth Street. Caltrans has provided maps for detour routes at sfhighwayprojects.com.

Above the sluggish mass of automobiles, workers in hard-hats and safety vests will mobilize on an empty stretch of freeway, tearing into the asphalt with heavy-duty machines. 

“This is a major rehabilitation,” said Caltrans spokesperson Lori Shepherd, explaining that crews will replace a joint across the full width of the freeway deck. After performing what’s essentially roadbed surgery, they will patch the area with durable polyester concrete. The material cures quickly, limiting disruptions to traffic.

Still, any East Bay resident who considered driving to Golden Gate Park this weekend may want to take the N-Judah train instead.

Scenes of Carmageddon are relatively uncommon in San Francisco, but this forthcoming crush of people and vehicles  could rival the nightmare traffic of a well-attended Dream Force conference or Warriors home game at Chase Center. Staff at Caltrans have urged people to take public transportation, which could help alleviate congestion or at least lower cortisol levels. 

Anyone landing Friday night at San Francisco International Airport and commuting home to an East Bay suburb has ample options, including SamTrans buses and BART.