“This means that over the 7.1 million miles Waymo drove, there were an estimated 17 fewer injuries and 20 fewer police-reported crashes compared to if human drivers with the benchmark crash rate would have driven the same distance in the areas we operate.”
Waymo claims 0.41 injury crashes per million miles against 2.78 for humans, an 85% cut. Waymo wrote the comparison paper and also wrote the second paper that defines the human benchmark. Human data covers freeways, where Waymo does not carry riders. Seventeen fewer injuries over 7.1 million miles is a thin number to hang a safety case on.