But they already have cars that drive themselves, without human interference. Google (and other companies') engineers have been driving them all over the country on test runs. Obviously if the car will drive itself to a specified destination autonomously, the physical state of the occupant is no longer an issue.

> Ie. the ninety-ninety rule.

Yes, fair enough -- I'm sure there are still edge cases, but the OP said, with respect to this technology, "... we won't see that kind of thing even within the next few decades, if ever."

The turning point will be when the technology's edge cases are less dangerous than a human driver's edge cases. That won't take very long.

This isn't the fantasy of "get wasted, get driven home, no matter what," but it seems good enough to ensure people are safe. Maybe you can get home, or maybe you sleep it off on the side of the road, or maybe your car drives you to a motel.