What is the kindest way of appealing to an elderly parent to give up the privilege of driving?

Take the car away and tell him it is in for extensive work. Unfortunately, that is what I had to do with my mom and had to keep things going until she stopped asking about the car. If you feel things have changed, then they have. You wouldn't want him to get into an accident and would not want him responsible for someone else's injury or death. I agree also with what others have said here.

You can ask your doctor to order an evaluation by an occupational therapist. this will tell you and his doctor loads about his reaction time and ability to safely control a vehicle. It's ALWAYS much better when someone with credentials is the one who tells the elder that they can no longer drive. Find out what transportation alternative for elders are available in their area.

What caused the accident? How far away from home was he? Does he use a cellphone while driving? It is so very difficult to take away this freedom from anyone, young or old.... it's their lifetime, so to speak.

Depending on what type of accident, don't forget that if you take away something from a elder you need to replace it with something else. You may become your parents full-time chauffeur, I had to do that with my parents but it got out of control after a couple of years and I had to set strict boundaries.... I wasn't going to drive them 2 or 3 times PER DAY because it was their routine back when Dad was driving.

The replacement has to be something they like, such as a senior bus if your area offers such transportation... or a cab company where you could set up just one driver to help them. Otherwise, you Dad may threaten to start driving again... my Dad threatens at least once every couple of months which gets me very upset. Then I tell him if only he and Mom would have moved to that nice retirement village, they could go daily on the community bus.