> Per vehicle mile traveled (VMT),
does scale matter at all though?
do crashes stay constant per miles driven
does scale matter at all though?
do crashes stay constant per miles driven
What other divisor makes sense to you?
let me ask you the opposite, what divisor(if any ) would make you question it.
As for bad divisors, accidents per car? Accidents per paint color? Accidents per average number of donut shops in the area? I dunno, tons of things.
It's always how vehicle safety data is calculated.
With human drivers it matters--high mileage drivers are more likely to be driving tired or in poor conditions, low mileage drivers often are losing their abilities. Thus you see elevated risk on the ends of the curve. That doesn't apply to machines, though.