My guess: they account for miles driven. If the elderly are driving less frequently and for shorter distances you can probably assume no long daily commutes dur

My guess: they account for miles driven. If the elderly are driving less frequently and for shorter distances you can probably assume no long daily commutes during rush hour, and less driving during evenings and inclement weather when accidents are likely to occur. Here's some data on the subject matter: https://www.fhwa.dot.gov/ohim/onh00/bar8.htm https://www.fhwa.dot.gov/ohim/onh00/bar8.htm 65+ drive roughly the same amount as 16-19 year olds. Driving peaks in the 35-54 cohort and drops sharply from there. I imagine drivers who are pushing 80 are driving significantly less than their cohort overall.