Aging population and driving

This story in today's San Diego Union Tribune, about a fatal accident involving a 71-year-old driver, prompted me to post a piece I've been working on for a couple of weeks...

Six months ago the first wave of Baby Boomers turned 65, prompting questions about how the nation's transportation system will adapt to an aging population. There are some benefits that may arise from having an older population, and there will undoubtedly be challenges.

As the population ages we may care less about our cars. A Gallup poll in 1991 found that 20 percent of Americans found driving to be a chore. The same response in 2006 got a 40 percent boost to 28 percent. When you drill down into the details of the survey, likelihood of taking a ride “just because it’s fun” decreases substantially with age. In short, an older population is less likely to enjoy driving.

And, contrary to most road-rage induced stereotypes, older Americans also drive more safely. (However, there are some limitations to that trend, as described below.)

In their 2009 study of aggressive driving behavior, AAA found that at age 16 nearly 60 percent of drivers show aggressive behavior. By age 35 aggressive driving falls to 35 percent and by age 60 is below 27 percent.

With an already aging population, safer driving is beginning to show up in accident statistics. According to the U.S. Department of Transportation:

“in 2010 the number of traffic fatalities in America fell to the lowest levels since 1949...despite a sharp increase in the number of miles Americans drove last year - 21 billion additional miles. In addition, the rate of road fatalities in the U.S. has also dropped to its lowest level since 1949. Over the last five years, traffic deaths have declined by 25 percent…And the rate of fatalities per million miles traveled fell to 1.09 from 1.13 in 2009.”

Transportation Secretary Ray LaHood credits this to “the combined efforts of DOT, states, law enforcement, safety organizations, and America's drivers who are taking personal responsibility for their driving habits.” But I also see a demographic shift at play, much as there was a demographic influence on falling crime rates, beginning in the mid-1990s.

However, as opening article implies, there are also substantial health issues that may impair the driving of older Americans.

For example, the likelihood of reporting some form of disability DOUBLES between the age groups 65-74 and 75 and older (from 25 percent at age 65 to fully half the population age 75+). Similarly, according to data from the U.S. Centers for Disease Control and Prevention 10 percent of older men and 15 percent of older women reported cutting back on driving due to a physical problem in the past year. And, for a combination of reasons, older drivers are likely to avoid driving in certain conditions. Older drivers tend to avoid driving at night, driving in bad weather, and (to a lesser extent) driving in heavy traffic.

All of this adds up to some very complicated issues facing the nation's transportation system. Fortunately, research is underway to better understand the implications of age-related health issues on transportation at institutes such as the Age Lab at MIT.