Quibbling... 28% in 2016 (https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/...), but this is after decades of awareness campaigns and enforcement. Then there's the ~70% of fatal accidents that happen with sober drivers. There might not be more to be had by addressing human factors (though I personally believe graduated licenses with more rigorous testing and much higher investments in public transit would help) so the focus on self-driving vehicles may not be misguided.