Speed limits in California are capped at 65 mph by state law (or 55 mph for undivided roads). Any agency wanting to set a lower speed limit has to conduct a speed study and cannot set the limit lower than the 85th percentile of measured traffic speeds.
Of course they can skip the speed study, or not repeat it every 5 years as required, but then tickets are effectively unenforceable on that road.
> Department of Transportation, with the approval of the Department of the California Highway Patrol, may declare a higher maximum speed of 70 miles per hour
Highways like the 101 are 55mph in some parts. Whats most dangerous about californian freeways are the people with ten feet of metal scrap in the truck bed going 40mph in the middle lane.
Of course they can skip the speed study, or not repeat it every 5 years as required, but then tickets are effectively unenforceable on that road.