What about an AI that refuses to start for a drunk driver? Boom, problem solved at the fraction of complexity and no innocent people get butchered up in the testing phase of a software that simply can’t reliably work with current tech.
Personally I like the ability to drive myself to the ER or away from an abusive spouse not being dependent on the false-positive rate of some device built by a notoriously shoddy car manufacturer, but to each their own I suppose.
As everything, it is a tradeoff. I would personally prefer not to have neither drunk drivers, nor overhyped smart-vacuums going around the roads.
But as for the very specific emergency case while you are drunk, it could be overridden with some visible sign turning on notifying other drivers - but it would need some law background, so eg. a cop can escort you in that case, etc. But tesla’s fake self-driving doesn’t help anyone.