It's a vehicle that can easily kill other people. It often does. It's reasonable to require drivers to be in good enough shape before trusting them with lives of random innocent people.
I'm not against enhancing safety, but I have serious concerns about whether auto manufacturers can implement such a feature securely, reliably, and without leaving it vulnerable to misuse by third parties. That said, I would support mandatory breathalyzers in all new cars. While this idea is likely too controversial and complex to become reality, I believe it could significantly reduce fatalities.
It's a vehicle that can easily kill other people. It often does. It's reasonable to require drivers to be in good enough shape before trusting them with lives of random innocent people.