The California Highway Patrol calls the night before Thanksgiving "Blackout Wednesday," in reference to one of the busiest drinking nights of the year.
It's the first official night of the holiday celebration, and it often means drivers are so drunk, they've blacked out.
One suspect already had been arrested by the CHP on Wednesday evening.
"Less than an hour after our maximum enforcement started, we got a 911 call following a suspected DUI driver," the CHP said. "As soon as we had all the officers in position, we made the arrest."
Traffic was far more nightmarish than usual on Bay Area roads, jammed with cars leaving and coming to town for the holiday.
"Real busy and congested," Uber driver James Glenn said. "A lot of people in a hurry,"
Linda Leblanc sure was.
"We are on our way rushing to the mall because they told us today is better than Thursday," she said.
Firefighters, too, were at the ready, expecting the usual Thanksgiving spike in house fires. They warn to keep an eye on the stovetop or the oven because it takes mere seconds for something to go wrong.