The non-DUI accidents you're talking about eliminating are the ones where cars are running into eachother. The problem is, even though regulations would be created to try to prevent those things, similar regulations being in place do nothing to prevent cars in 2-d from running into eachother, pedestrians (I've been hit three times, once on the sidewalk, twice in a parking lot while standing still in plain sight, wearing an orange and yellow vest since I worked there), and non-mobile obstacles like trees, buildings, and rivers. The problem isn't with regulations and planning, it's with people not paying attention to those regulations, or to what they're doing at all.
Added to that is maintenance - right now, airplanes are the safest way to travel, but that's partly because they get maintenance and checks done on them every single time they land, and right before every time they take off. Cars, not so much - as evidence for this, I would point out the street I used to live on, which was littered with car parts that had fallen/flown off of cars as they went over the bump from the local train tracks. Most often hub caps, occasionally a mirror or door handle, once an entire fender, which the owner of just left, laying in the middle of the road where it fell. You want these people going over your head? Are you completely insane? The first bit of turbulence they hit, and they'll be dropping a wing strut into your pool, then wobbling off like it's not important, and trying to sue the maker of their flying car when they fall out of the sky and crash on a school playground.