Proponents of self-driving cars commonly argue that, in general, they are safer than human-driven vehicles. According to the National Highway Traffic Safety Administration (NHTSA) human error is the cause of 94% of car crashes
, where human errors include drunk driving, speeding, distraction, and fatigue.
However, a recent report from RAND Corporation says autonomous vehicles would need to be tested “hundreds of millions of miles and sometimes hundreds of billions of miles”
to gain enough information to compare its safety to human-driven automobiles.