After accounting for miles driven, fatal crash rates start increasing around age 70, peaking at 85+ near a level equal to the rate of 16-19 year old drivers, based on a preliminary skimming of the data I could find.

Based on anecdotal evidence and experience, I absolutely believe that. Just a few weeks ago near me an elderly driver caused a crash that killed herself and a passenger in another car when she failed to follow a curve and drove head-on into opposing traffic on a road with a 40MPH speed limit.