One day they'll be safer than human drivers. But billionaires cutting corners with safety to move fast developing their fancy tin cans and getting people killed seems to be theme this week.
That'll be the time when computers have developed sentience and an understanding of the outside world. Driving is a cooperative effort, it requires intelligence, and a theory of mind.
A few years ago there was that video where a Tesla kept slowing down because it identified the Moon as a yellow traffic light, and there was this other occasion where it drove behind a truck that had loaded traffic lights and kept identifying those. That would need to stop first.
You can see that at the point where the Tesla busts through the stop sign - any normal person would associate a stop sign with danger and proceed with caution, except of course the teenager with L plates.
Current AI is better than a drunk teenager, but that's too low a bar. Driving sober, well-rested and in daytime (driving during the day also keeps you away from all the other drunkards) is actually remarkable safe. Remember that the safest mode of travel per journey is not the airplane, it's the motorcoach.