When my Grandmother gave up driving, she used it as an opportunity. In a Sampiro-esque bit of maternal manipulation, she had a huge leash to bring her “keepers” to heel. Grandma had always liked doing her shopping in one big load. But once she had a legitimate reason to yank family members over to her place at whim, she liked shopping for each little thing separately. She would “forget” things on shopping trips and remember it later that day, requiring another trip. She quickly learned not to say what it was she needed on the phone because the keeper might have it at their place and drop it off or go to the store and get it and then drop it off.
So for my grandma, losing the license was an improvment in her life rather than a liability.
The best chart that I have found ( http://www.dmv.ca.gov/about/profile/rd/resnotes/revised_teen_trends.html ) does agree that there is a difference in per capita and per mile. On a per mile basis elderly (75+) look as bad as youth (25-) [btw: oh gawd! I’m not in that category any more? Damn I’m gettin old…]. However, the middle is quite flat. ~30 to 65 is pretty much the same thing.
OTOH, testing people over 80 is not the end of the world for them. Yes, we would have to re-evaluate how we deal with them, and I am sure that there would be a huge increase in retirment communities, but that’s not necessarily a bad thing. Fer’ex: I honestly believe my dad’s parents are a perfect example of this. My grandfather got a speeding ticket one month before he died, at age 96. I’m quite certain he would have retained his license throughout extra examinations. My grandmother OTOH, who really only started driving after her husband died, should not be allowed to touch the stearing wheel of a car.
However, The Real Message[sup]TM[/sup] of the figure above is that we (as a society) are doing a horrible job in training our youth to drive safely. I see this every day when I’m out on parking lot duty after school.