What doesn't matter is who wins in average conditions. Because averages are just that: averages. But actual driving is full of non-average situations, whether they are created by weather, other human participants in traffic, animals, whatever...there's millions of surprising non-standard situations happening each day in traffic, and current technology isn't even able to reliably detect when it's facing such a situation, much less capable of handling them entirely on its own.

And yet autopilot is doing millions of miles a year with fewer incidents than humans, and expanding in capability (for example taking lane changes and turns), all while constantly lowering the level of accidents.

I think average conditions do matter, and supervised computers will continue to take over driving until humans are simply not required. Of course they will not replace humans this year or next, but at some point humans will be passengers, not drivers.

Right. And that's why it's not rolled out everywhere yet. But it's clearly getting closer and closer. It's probably less than 20 years away.

As someone who works in insurance, I can tell you that the vast majority of accidents occur in adverse conditions.

Creating an AI that only functions on dry sunny days is basically useless from a safety perspective.

...though it does save people time since they can be doing something else while in transit!

The stats aren’t good enough to be sure yet. They’re encouraging, and if you’d asked me in 2010 I absolutely would not have guessed that a few billion miles of experience wasn’t enough to know for sure, but turns out we need more data.