but if waimo is opting out of difficult days, leaving the human to pick up that part, it will severely bias the safety comparisons because then of course humans

but if waimo is opting out of difficult days, leaving the human to pick up that part, it will severely bias the safety comparisons because then of course humans will have more crash per mile then any 'same period comparison' are destined to just measure this first-pick bias. they are going to need to compare with the driver data from the period before waymo introduction (while accounting for other constraints, so excluding rides on freeway, etc)