My 92 year old dad thinks he can still drive. He recently had an accident (no one was hurt,only property damage). He is stubborn. My 92 year old mother says it is time for him to quit driving. The last time I rode with him (about a month ago) he had good command of the vehicle. He worked hard to get his drivers license renewed last year and passed the written and road test. But things have changed for him physically. I believe he does not want to admit this. The recent accident should be his wakeup call. It is for the family.
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.