We're allowed to drive in California too - its supposed be for "essential" travel only, but that is pretty broad. I'd estimate in the Bay Area, traffic is only down by 50% or so (though certain commute routes are more dramatically impacted).
"Everyone is required to stay home except to get food, care for a relative or friend, get necessary health care, or go to an essential job... If you need to get into a car or on public transportation to go for a walk or run, you’re going too far."
