Traffic deaths are surging in Japan because of all the seniors behind the wheel

As people age, they tend to lose sharpness when it comes to reaction time, spatial awareness, and vision.

In Japan, where the elderly population has been swelling for the past two decades, that shift has led to an alarming trend on the road.

Recent data from the country's National Police Agency show that 13% of traffic deaths (459 fatalities) were caused by a driver 75 years and older in 2016. That's up from 7.4% in 2006. What's more, senior-caused traffic accidents, fatal or not, have been increasing since the late 1990s.

Two factors seem to be at play. The first is that the rate of traffic fatalities overall has actually been going down - the 2016 figure was a 67-year low for Japan. But the other is that Japan's elderly population keeps growing, which means more older drivers are on the road.

As a result, the elderly are keeping the traffic death count higher than it would be if they were to hand over their keys.

Private industry and local governments have tried to persuade them to stop driving. At least 10 years ago, Japanese banks started offering higher interest rates to seniors who gave up their drivers' licenses. Department stores started offering free delivery to senior customers. Recently, one town began awarding seniors one year of free bus rides, at which point taxi services began pushing discounts of their own.

Such strategies may be necessary, since Japan isn't getting any younger.

Census figures from 2015 show that 26.7% of Japan's population is at least 65 years old. At the current pace, estimates suggest the proportion will rise to 33% by 2035 and 40% by 2060.

Japan's aging population has led to other consequences as well. Millions of older people have put an enormous strain on Japan's social security system, burdening younger generations that are increasingly deciding not to start families.

Economists have observed that this trend of low fertility, rapid aging, and low consumer spending make for a vicious cycle. As couples spend less, the economy tightens, which gives them even less incentive to bring a baby into the world, which means there are fewer consumers. And the cycle continues.

In the case of traffic deaths, Hiroshi Takahashi, a former professor at the International University of Health and Welfare Graduate School, told Bloomberg that the Japanese government could curb the growing fatality rates by giving seniors more ways to get around.

"The government is restricting their movements without giving alternative mobility options, which makes it really difficult for them to stop driving," he said.

If Japan's elderly do hand over their keys, their best options are public transportation - which can be hard for those unable to walk long distances - or recruiting a family member to drive them around.

Faced with those two imperfect options, many Japanese seniors have opted to stick with their own wheels for the sake of independence, no matter the risk.