there is a big % of old people where i live,we call it gods waiting room, and alot of the time when there is a car accident it is nearly always the fought of an elderly driver, they drive too slow and never look at junctions, they definately need retesting as alot of the road sighns are new to them, when they started driving they didn't need to take a test as there was very few cars on the road, things have changed and i belief that when you reach 65 you should be retested then at 70 then every year after that.