Hi!
You are justifiably annoyed by some of the answers to you very convoluted question. Let's not go there, shall we?
Now, those who said the main cause of accidents are the ones who drive at excessive speed were right. This is a proven fact.
Age gets to us all but the arbitrary 70 is a misnoma. There are so many people who degenerate faster and so many who don't, that to quote an age is very misleading. However, I do know what you mean.
Doctors in the UK are very observant people when age takes a toll on people in general but more with drivers.
The majority of elderly people drive more responsibly that the young (mentioned earlier) and less accidents are recorded involving the elderly.
Your experience might be of an individual in you village or town because you see the driver regularly but not all are the same.
I would ask you to be a little more understanding, give way when this driver approaches and remember that, one day, we will all possibly be at the stage in life when others might consider us unworthy of a Drivers Licence.
Any delay to a journey cannot be more important than to arrive safely.
I am 66 years of age, a responsible driver, Police trained and observant of all motorists actions because I always think the other fellow is going to make a mistake and take care.