This year, news of traffic accidents involving elderly drivers have been much more frequent in Japan. According to the 2017 report by the National Police Agency Transportation Bureau’s “Number of deaths by age group”, elderly drivers who retain their driver’s license were around 1.9 times more for those over 75 years old, and 2.3 times more for those over 80 years old compared to 2007. Moreover, the number of fatal accidents and fatalities have also increased.
So what could be the possible causes?
According to the National Police Agency’s “Human factor comparison of deaths”, the most frequent accidents occurred due to operator errors such as wrong steering and brake/gas pedal mistakes, which accounted for 31%. In particular, wrong stepping of brakes and gas pedals only accounted for 0.8% of total drivers under 75 years old, but for drivers over 75 years old, it was 6.2%. When the latest “cognitive function test” for elderly drivers who caused the accident with fatalities were performed, “possible risk of having dementia (type 1)” or “possibility of cognitive function deterioration (type 2)” accounted for about half. Therefore, it can be inferred that cognitive decline significantly affects the occurrence of fatal accidents.
However, accidents involving the elderly are not only due to the decline in cognitive function but also the narrowing of vision, the decline in dynamic vision and the decrease in exercise capacity. These may culminate to cognitive mistakes such as oversights of pedestrians and vehicles at intersections, and errors such as wrong operation of steering wheel, brake and gas pedals.
To prevent accidents, one way is to encourage surrendering driver’s licenses voluntarily, and in order to reduce accidents, introducing the use of vehicles equipped with better safety controls such as preventing gas pedal mistakes.
The pie chart below shows data from the National Police Agency Transportation Bureau’s “Cognitive function test results” of elderly drivers 75 years old or older who caused fatal accidents in 2017.