But therein lies the problem. Any system that tries to apply a blanket policy WILL run into these very real problems. Regardless of what the actual intent was (blocking drunk drivers in this case), the unintended consequences of this will be severe.

I completely agree with you on this.

But again, my comment wasn't about this system, but drunk driving in general.

I acknowledge that situations exist where drunk driving is the only option (like with the flood/tornado/vulcano examples mentioned in other posts). But for most scenarios there is often a better solution that doesn't involve drunk driving.

My very real problem of being trapped in a car while being attacked a bear?!?!

Picking out one particular extreme case and making fun of it is a pretty good technique in a debate, but it rather misses the point in an authentic conversation. The point is that the sum total of all exceptional use-cases for cars (including, but not limited to running from bears) is actually large enough in practice that this kind of rule may not be worth its opportunity cost.

If we eliminate drunk driving (10k deaths per year, many more injured) in exchange for every single person in those fantastical scenarios dying, lives will be saved by many orders of magnitude. And that's granting that your drunk pregnant wife trapped in a blizzard wildfire with grizzly bears scenario actually happens.

Snowstorms happen across a lot of the USA for a good 3-4 months a year. If stop/start/slow/slide driving in winter conditions kills your car, you could wind up killing way more than 10k people, either through exposure, or because a snowplow or another vehicle didn’t see the killswitched, snow-covered car and rammed right into it.

I like living in snowy places. I could see this being a real problem, just like snowy conditions mean self-driving won’t work for me for many years in my only vehicle.

I tell my car how it drives. Not a computer.

I don't want a computer making the decision as to whether I can drive the car I paid for or not.

Maybe when society finally makes its final swirl down the toilet and we're finally not allowed to use private vehicles on public infrastructure, being forced to use government/corporate sponsored vehicles - maybe then they can tell me how to use _THEIR_ vehicle.

Well this is where they want it to go in the long run indeed. "You will own nothing and you will be happy". In this case something like Car As A Service.