And if anything, I'd expect machines to have faster reflexes than humans. The Medium article is walled off, but I found another source[1]:
"The child reported minor injuries and did not require transportation to a hospital. ... Waymo said at the time that the child ran into the street from behind a double-parked SUV and that the vehicle braked hard before contact, reducing speed significantly before impact."
Edit: Waymo's blog[2] says it "reduc[ed] speed from approximately 17 mph to under 6 mph before contact was made", and that "our peer-reviewed model[3] shows that a fully attentive human driver in this same situation would have made contact with the pedestrian at approximately 14 mph".
> Braking distances exist for AI-driven vehicles just as much as human-driven ones.
Reaction times differ, though, and abilities to blend deceleration and turning and awareness of what else is around.
(Waymo's tendency to be a good defensive driver and bleed a few miles per hour at anything odd help too... though it is worth noting that if Waymo was 1MPH slower, that 6MPH collision wouldn't have happened at all).
