What's your source for this? Most sources I'm finding say alcohol-impaired driving is involved in about 30% of US traffic deaths.
https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/...
Regardless, the numbers are very good for the US, compared to the rest of the world. iihs.org[1] indicates the US is averaging somewhere around 1.5 fatalities per 100 Million miles traveled.
Compared to the rest of the world... that's pretty decent. Most of the places with significantly high fatality rates are not the places that will be purchasing self driving electric vehicles anytime soon...
[1] https://www.iihs.org/topics/fatality-statistics/detail/state...
2021: 42,915
2020: 38,824
2019: 36,355
2018: 36,835
2017: 37,473
According to https://en.m.wikipedia.org/wiki/Motor_vehicle_fatality_rate_... the last time the US had fewer than 30,000 traffic fatalities was 1945
If every single driver were legally drunk at all times, poorly designed vehicles will still result in more and worse accidents then well-designed.
The point is that the design of the vehicle, or anything, needs to be as good as possible regardless of anything else, and there is no overriding excuse not to.
It's not like the poorly designed controls are necessary for some other even more important reason.
If both roads and drivers were all excellent, the vehicle still needs to be as excellent as possible. If all other factors are so good that only 10 people die each year from car accidents, there is still no excuse for making vehicles less safe and make that become 20.
Alcohol, lack of alcohol, good roads, bad roads, speed limits, none of that matters.