Age concerns

Driving means manipulating a dangerous piece of machinery at speeds beyond anything for which evolution has prepared you, reacting to a multitude of visual signals and warnings, calibrating and recalibrating velocity, distance, direction and stability, all the time guessing the intentions and anticipating the possible actions of unnumbered others performing the same tasks in the same places at the same times. And this while talking, listening, daydreaming, trying to work out where you are and where you should be. Yet we know that as we get older we get worse at most things. Surely age affects this too?

It does, but the relationship is not as straightforward as it is in the golf performance of a friend of mine who makes himself miserable by measuring his age-related decline in terms of how far he can hit the ball. Driving, and most measurements of it, is more complicated (though not necessarily more demanding) than golf. We should keep pointing this out because every so often there are government mutterings about restricting older drivers — which means all of us, eventually.

Age-related accident statistics generally show a U-shaped pattern, with the under-25s at highest risk, a decrease through middle age, then an increase in old age — although even octogenarians have only a fraction of the number of accidents sustained by the young. But concealed within most studies are complicating factors and reporting bias. Frailty, for instance, means that the physical consequences of accidents are often more severe for the elderly, which in turn means that their accidents are more likely to be reported and so enter the statistics. Therefore, the old could be over- represented in accident figures. On the other hand, such figures usually do not take into account the numbers of drivers in each age category nor the mileage driven.