A study by scientists at Nagoya University has found that elderly drivers are significantly more likely to express anger and aggression when they have to stop at a red traffic light, a discovery that may go some way towards explaining the soaring number of crashes caused by older drivers in Japan.
A team led by Nobuyuki Kawai, an associate professor of cognitive science, used a driving simulator to monitor levels of anger and annoyance among two groups of people when they had to stop at four consecutive red lights. One of the groups was aged between 19 and 31 and the second group from 65 to 74 years old.
In the study, published in the journal Japanese Psychological Review, the researchers noted that there were no changes in the level of irritation – determined by measuring increases in oxyhaemoglobin in the left frontal lobe – when the drivers encountered a series of green lights.
While the 22 younger drivers remained relatively calm when they had to stop at red lights, the 20 subjects in the older test group experienced significantly greater activity in the left frontal lobe and showed signs of frustration and anger.
Previous studies have suggested that age-related declines in cognitive abilities, such as selective and divided attention, contribute to road accidents in elderly people. The new study says older drivers are further irritated by being “restricted from driving freely”. That tallies with last year’s figures on car crashes caused by people over the age of 75.
The annual report on vehicle accidents in 2016 released by the National Police Agency in February revealed that there were 418 incidents involving a driver over the age of 75 causing a road fatality during the year. That translates as 7.7 road deaths per 100,000 drivers, more than double the number of road deaths caused by drivers under the age of 75.
Drivers aged 75 or older accounted for nearly 13 per cent of all road accidents throughout the year, while 168 of the 418 accidents in which someone died were single-vehicle incidents, such as a car being driven into a pylon. Among elderly drivers, single-vehicle accidents accounted for 40.1 per cent of the total, significantly higher than the 22.9 per cent of all other drivers.
The police statistics do not identify cases in which an elderly driver was involved in an accident involving traffic lights, although a number of cases have been reported.
In May this year, a 90-year-old woman drove through a red light in the town of Chigasaki, southwest of Tokyo, and hit a group of pedestrians on a crossing before swerving onto the pavement. A female pedestrian was killed and three others sent to hospital.
The elderly woman was arrested on charges of negligent driving resulting in death and injury.