Actually, excessive speeding is the #1 cause of road deaths.
Distracted driving is hands down #2
THEN comes “impaired” driving.
You have noticed how the standard for “impaired” has been being forced ever downward, haven’t you?
The 2016 national data shows that:
Distraction-related deaths (3,450 fatalities) decreased by 2.2 percent;
Drowsy-driving deaths (803 fatalities) decreased by 3.5 percent;
Drunk-driving deaths (10,497 fatalities) increased by 1.7 percent;
Speeding-related deaths (10,111 fatalities) increased by 4.0 percent;
Unbelted deaths (10,428 fatalities) increased by 4.6 percent;
Motorcyclist deaths (5,286 fatalities the largest number of motorcyclist fatalities since 2008) increased by 5.1 percent;
Pedestrian deaths (5,987 fatalities the highest number since 1990) increased by 9.0 percent;
and Bicyclist deaths (840 fatalities the highest number since 1991) increased by 1.3 percent.
Mandating universal use of self-driving cars would greatly reduce fatalities on the road. However..
The more prevalent they become the slower they will all have to move to keep the control grid from crashing, so there will be a greater number of people dying while waiting hours for the self-driving ambulance to slowly roll up to the scene. And there will be a large number of increased suicides and other stress-related deaths from sleep-deprived people who just can't face another 6-hour jerk-start-travel five feet-jerk-stop-repeat-endlessly commute to get to their job 12 miles away.