In defense of older drivers

The notion that senior drivers have higher rates of crashes because they are poorer drivers is largely a misconception, according to a commentary in CMAJ (Canadian Medical Association Journal).

The overrepresentation of seniors in fatal crashes is mainly due to their "frailty" — "the age-related increase in the probability of dying as a result of a crash," writes Dr. Ezra Hauer, professor emeritus, Department of Civil Engineering, University of Toronto. "Frailty as a cause of overrepresentation should not be confused with the ability to drive safely."

The modest overrepresentation that remains after accounting for frailty is the result of several factors. First, seniors drive more on streets with many intersections where the crash rate is higher than on freeways.

Second, crashes with seniors tend to be more fully reported to the police because they are seldom single-vehicle crashes and because the crash often involves injury to the senior. "For these reasons, a larger proportion of seniors' crashes end up in the official statistics; this too contributes to the appearance of overrepresentation and has nothing to do with the ability to drive safely," writes Dr. Hauer. When seniors are compared with nonsenior drivers who drive the same amount, the overrepresentation disappears completely except among those who drive very little.

"More than four-fifths of those killed when the driver is 85 years or older are the drivers themselves; among drivers between the ages of 16 and 59 years, two-thirds of those killed are other people. Unlike younger drivers, older drivers are a danger mainly to themselves."

However, despite the data, many Canadians believe that older drivers are a significant threat to traffic safety. Physicians should base their recommendations about delicensing senior drivers on facts rather than on incorrect beliefs.