Self-driving cars being planned by Google Inc. and global automakers may help counter slumping demand from younger customers by tapping the fastest-growing demographic in the world’s largest vehicle markets: the elderly.

As baby boomers age in markets including the U.S. and Japan, rising numbers of older drivers being killed or injured in accidents may spur demand for autonomous vehicles. With as many as 90 percent of traffic accidents caused by human error, a key benefit of the technology is boosting safety, executives from automakers including General Motors Co. and Toyota Motor Corp. said at an industry conference in Tokyo last week.

“Seniors are often regarded as the victims of traffic accidents, Moritaka Yoshida, managing officer and chief safety technology officer at Toyota, said this month as the company announced plans for automated-driving systems. “However, recently an increasing number of accidents are caused by senior drivers.’’ 

Japan, the world’s fastest-aging major economy and the third-largest car market, is at the forefront of the accident trend: of the 4,411 people who died on the road in the country last year, more than half, or 2,264, were 65 or older, according to data from the National Police Agency.

“Driver-assistance and autonomous-driving technologies will definitely help stimulate demand among the elderly by assuring them driving can be very safe,’’ Zhou Lei, a senior manager and auto-industry consultant at Deloitte Tohmatsu Consulting Co. in Tokyo, said in a phone interview. “What’s happening in Japan will also occur in the U.S. and especially emerging countries like China, and the demand will be huge.’’

Carmakers are gradually introducing automated-driving systems that may ultimately lead to self-driving vehicles. Mountain View, California-based Google, operator of the largest Web search engine, has been testing driverless cars in the U.S.

Toyota, the world’s largest carmaker, said Oct. 10 it will introduce systems in about two years that will enable cars to communicate with each other to avoid collisions. Detroit-based GM, the largest U.S. carmaker, is planning vehicles by 2020 that will be able to drive themselves on controlled-access highways.

Nissan, Japan’s second-largest automaker, said last month it had obtained a permit to test autonomous cars on public roads in Japan. The Yokohama-based company plans to introduce a self-driving vehicle by 2020.

“Autonomous driving could be very helpful to people who have physical challenges, or the elderly,” Mitsuhiko Yamashita, executive vice president of Nissan, said at last week’s World Congress on Intelligent Transport Systems in Tokyo.

The rising proportion of accidents involving the elderly may have more to do with aging demographics than driving ability. People aged 65 or older accounted for 16 percent of licensed drivers and 17 percent of the 32,367 traffic deaths in the U.S. in 2011, the National Highway Traffic Safety Administration said in April. Total traffic deaths, including those among the elderly, fell 25 percent from 43,005 in 2002.

Once involved in an accident, older people are also at greater risk of dying because their bodies are more fragile. Per mile traveled, fatal crash rates increase starting at age 75 and rise notably after age 80, the main cause being greater susceptibility to injury and medical complications, according to the U.S. Centers for Disease Control.

The higher percentage of traffic deaths involving elderly in Japan ― 51 percent, versus 17 percent in the U.S. ― is mainly due to Japan’s older population, Kazunobu Nagaoka, a researcher at the Tokyo-based Institute for Traffic Accident Research and Data Analysis, said in a phone interview. (Bloomberg)