I believe most people are inconsistent drivers. Usually they do a reasonable job, but some fraction of the time they're worried about a sick kid, or a job inter

I believe most people are inconsistent drivers. Usually they do a reasonable job, but some fraction of the time they're worried about a sick kid, or a job interview, or a recent breakup, or whatever, and they aren't paying attention. There are some truly consistently horrible drivers. But in general most people do ok most of the time. I think the real challenge is cutting of that really bad end of the distribution, which autopilot seems to be doing.