While I understand your idea that people should get retested every 5 years, I am growing quite weary of the "teenagers are bad drivers" statistics and arguments. Of course they are; they are just learning how to drive. A baby learning to walk does not walk with the ease or comfort of a five year old, because it takes time and practice to walk effectively. The same argument can be made for teenagers driving, they will get better with time. Not many people question the driving priveleges of the 25-50 age group because these people have honed their driving skills. However, it is beyond unlikely that the elderly's driving skills will improve, and in my experience, the elderly take far less accountability for their actions on the road than young people.