Simple fix:
Require all cars to be fitted with speed limit governors set to 15 miles an hour, add 5-point aircraft style seat belts/restraints, and supply 50 mile an hour steel bumpers on all sides of the car, Further, require all existing cars be RETROFITTED up to the current safety codes within one year.
PRESTO! Near-zero fatalities on the road!
(Of COURSE, you could never actually DO this!!)
Wait. We can do this now!
And they are electric
Everyone gets a bumper car from the carnival