No proof seniors drive less safely

The Jan. 3 Kyodo article “Traffic deaths down but not for seniors” reports that, for the first time, half of all victims of fatal traffic accidents in Japan during 2010 were 65 or older. The piece then opines that the imbalance in the distribution of fatalities “suggests a greater need for measures to prevent seniors from having accidents,” including workshops and a system that encourages the voluntary surrender of driver’s licenses.

I don’t believe that this conclusion is justified. When an overall population ages as rapidly and for as many consecutive years as Japan’s has, every year the number of nonsenior drivers shrinks and the number of senior drivers expands. Consequently, it is statistically inevitable that, at some point, more than half of virtually anything you’re measuring will be attributed to the population that has expanded rather than to the population that has shrunk.

The bottom line is that unless you include the proportion of the driver populations in your statistics, the fact that half of all victims of fatal traffic accidents in Japan during 2010 were 65 or older tells you absolutely nothing about who the safer drivers are. It could well be that, after we factor in the actual degree of their shrinking population, nonsenior drivers — although responsible for only slightly less than half of all traffic fatalities — are actually driving less safely than ever!

I do, however, wholeheartedly endorse the idea that senior drivers’ workshops can be particularly beneficial: first, to educate about the additional challenges that aging presents to the driver and then, perhaps more importantly, to introduce seniors to sound driving practices designed to mitigate those challenges.

james taylor