There are two widely-held stereotypes of elderly drivers: that as a group, they are more at risk of accident, and that this stems primarily from their defective eyesight. There is some truth in the first assertion, but what I want to argue is that the second stereotype is incorrect - elderly driver's difficulties do not stem so much from visual defects, but rather from problems with attention and generalised "cognitive slowing". Moreover, these difficulties apply only to a minority of elderly drivers, because they tend to be the result of age-related health problems rather than due to normal, healthy ageing. Many studies of accident statistics show a U-shaped pattern. The greatest risk of an accident is for the under-25's. The risk decreases during middle age, and then increases again for the over-65's. Evans (1988) used data from the U.S. Fatal Accident Reporting System: compared to 40 year-olds, 65 year-old males had 33% more fatal crashes per unit distance travelled, and 65 yearold females had 77% more fatal crashes. One of the many problems in assessing risk is to know what the exposure rate is of the population concerned (see Hakamies-Blomqvist 1998 for a discussion of this and other related issues). There are some indications that the elderly drive less miles and confine their driving to undemanding, highly familiar conditions during daylight hours. If this is correct, then the elderly's risk of an accident might be even higher than it might at first sight appear, because the elderly on the road for less time in which to have their accidents! The problem is in adequately assessing the exposure risk of different age-groups of drivers. Author/publisher)
Samenvatting