This subject came up at the time of the last kid getting hit by a car on a bike because the driver was 81 years old. But it wasn't talked about much because the police said age was not a factor it was a blind corner and there was nothing she could have done. I was recently reminded why retesting drivers is a good idea at any age.
I met a very cute woman who has gone partially blind in one eye. She warned her passenger, my friend, that she isn't a very good driver, especially at night. There was a little bit of driving on the sidewalk involved with there commute. This isn't just an age thing, this woman is probably younger than me or about the same age. She is a very nice person from the one time I met her but her ability to drive safely has changed. She had a tumor removed from her brain in the the process lost considerable amounts of vision in one eye. Not trying to say anything bad about this wonderful person I'm just using her as an example of why retesting drivers is not just an age issue and should not be thought of as one. People change and just because they knew the rules when they were 16 doesn't meant they are still capable of driving in a safe manner. Plus anyone who claims age discrimination is forgetting that we already discriminate based on age when it comes to driving, but apparently age discrimination is only acceptable when discriminating against those who can't vote, which is also age discrimination.