The Snow Belt?
One aspect that they might be missing out in California is driving in a snowstorm, especially at night. It really changes everything when most of your vision is filled with an almost opaque wall of snowflakes flowing toward you. I'm not sure exactly how I see where I'm going in the snow. I follow the tire tracks or tail lights ahead of me if there are any. Otherwise I try to distinguish between the drifts and the bar ditch as best as I can. If there are phone poles I try to remember how far away from the road they are. I once had to turn around leaving a small northern plains town in a snow storm because once the phone poles ran out, there was nothing at all to drive by. Another thing that an autonomous car might have trouble with is getting around a break down or accident where someone is directing traffic by hand. I hope that they program the cars to not close off side driveways when approaching a traffic light. The car should stop short and flash the lights to let a car out, not close up the gap and block them in. For some reason, when I read about autonomous cars, I always flash back to the movie Airplane, with Otto the Autopilot.