GOTSU, Japan — Before Atsumu Yoshioka, 81, decided to give up driving, there were signs it might be time.
During a visit to a shrine in rural Shimane Prefecture in western Japan, Mr. Yoshioka, a retired furniture maker, forgot to set the parking brake, spooking his wife, Kazuko, when the car drifted backward.
Then one morning as he backed out of the driveway, he rammed into a large urn in front of their home. Haunted by television news reports of fatal accidents caused by older drivers, Mr. Yoshioka called it quits.
“Before I caused any serious accidents,” he said, “I decided to give up driving.”
As Japan’s population ages, so do its drivers. Japan has the oldest population in the world, with nearly 28 percent of its residents above 65 years old. One in seven people are over 75. In the United States, by comparison, that figure is closer to one in 16.
According to data compiled by Japan’s national police agency, drivers between 16 and 24 are more likely to cause traffic accidents than any other age group. But last year, drivers over 75 caused twice as many fatal accidents per 100,000 drivers as those under that age. Among drivers over 80 years old, the rate was three times as high as for drivers under that age. The news media regularly features grisly reports of deaths caused by older drivers, some of whom are later discovered to have Alzheimer’s disease.
Since 2009, all drivers 75 and older must submit to a test of their cognitive functioning when they renew their licenses, typically once every three years. Under a new traffic law that took effect in March 2017, those who score poorly are sent to a doctor for examination, and if they are found to have dementia, the police can revoke their licenses.
More than 33,000 drivers who took the cognitive test last year showed what the police deemed to be signs of cognitive impairment and were ordered to see a doctor. The police revoked just over 1,350 licenses after doctors diagnosed dementia.
An additional 460,000 older drivers showed slight impairment of their cognitive functions, based on their performance on the test, but were allowed to keep their licenses if they took a three-hour traffic safety course.
Many more, for a variety of medical or psychological reasons, have voluntarily decided they are no longer safe to drive and have given up their licenses. The police and local governments, along