Safe Driving

by Miriam Karmel

Illustration: Belle Mellor

Drinking and driving don't mix. But what about aging and driving? That question is the focus of a growing public health debate that has the American Medical Association (AMA) and the American Automobile Association (AAA) talking. The issue has taken on greater urgency since last summer, when an 86-year-old man plowed his car through a crowded California farmers' market, after he reportedly stepped on the gas instead of the brakes. Ten people were killed, dozens injured, and the driver faces 10 felony counts of vehicular manslaughter.

While the media questioned the role that age may have played in this tragic incident, most experts agree that safe driving is a matter of function, not age. As AMA President-Elect John C. Nelson puts it: "A woman in her 80s in good health may be a safer driver than [her] 20-year-old grandson who happens to be on pain medication for an injury."

Still, functional measures—motor ability (including reaction time), cognition, and visual sensory ability—do diminish with age. In fact, an AAA Foundation for Traffic Safety study released in February 2004 found that drivers older than 65 are more susceptible to automobile accidents than other age groups—except for teenagers—due to declining perception and motor skills. The report also stated that drivers over 65 are more likely to die in crashes than drivers under 64, who are less fragile and more able to withstand injuries.

Visual acuity—how much detail you see—remains the standard measure for driving safety in most states. If vision is a yardstick, then contrast sensitivity is every bit as important, says Lylas Mogk, MD, medical director of the Henry Ford Visual Rehabilitation and Research Center in Detroit. The loss of contrast diminishes with age, making it difficult, for example, to distinguish a white car on a snowy roadway.

To increase contrast, Mogk advises wearing yellow tinted lenses on gray days and at dusk and dawn; and amber tinted lenses on bright, sunny days for glare control. For night driving, she suggests the kind of yellow glasses that hunters wear in the woods. Clip-ons work fine, she says, and adds that a tennis-style cap with a visor provides better screening than a car's visor. Most people with really poor vision are aware of the problem and take themselves off the road or limit their driving, Mogk says.

"Vision clearly plays a role, but it's so much more than vision," says Mogk. "We need to be testing for other things." She cites loss of movement, cognition, and judgment as factors that impair driving safety. "You can have 20/20 vision, but if you can't turn your head, you are dangerous."

Driving assessment clinics that test these other factors have sprung up in recent years across the country to provide expert assessment of a person's total competence as a driver.

While some drivers seek out such clinics, most referrals come from health care providers or concerned family members, says Cynthia Owsley, director of the driving assessment clinic at the University of Alabama at Birmingham.

For a typical first visit, patients take a battery of performance tests to measure vision, memory, visual perception, attention, and cognition.

Those who pass then get behind the wheel with a specialist, who observes the driver's various driving skills, such as the ability to stay within the lane, see lights, steer clear of parked cars, and merge with traffic.

Owsley's clinic may suggest that the patient refrain from driving, though it's up to the referring physician to report that recommendation to the state licensing bureau, which has the ultimate authority to withdraw driving privileges. A visit to a driving clinic "is not necessarily a step toward not driving," Owsley says, adding that almost half her clients are determined fit to drive.

In many cases, a specialist will approve driving under certain conditions, such as using familiar roads and driving during daylight. Other modifications may include equipping the car with larger rear and side mirrors, larger and brighter dashboard displays, pedal extenders, and easy-locking seat belts.

Such compensations, says Owsley, are usually something a client can live with. It's usually better than not driving at all and many people have only a few specific places they need to drive to, she says.

Owsley says that the farmers' market tragedy may have unfairly tarnished the image of older drivers. "If we look at all the older drivers and the many miles they drive, that accident was a rare occurrence," she says.

Miriam Karmel has written about medical issues for Utne Reader, Self, and other publications.

What's Your Driving IQ?

If a driving assessment clinic feels like too big a step, try a self-test to determine whether you're a danger to yourself or others on the road. Lylas Mogk, who also chairs the American Academy of Ophthalmology's vision rehabilitation committee, poses eight questions for you to ask yourself:

When you're driving, do objects, like parked cars or pedestrians, catch you by surprise?
Do you have difficulty seeing another car before the driver honks? Do other drivers honk at you for reasons you don't understand?
Do you have a stiff neck or limited neck rotation?
Are your reflexes slower and reaction time longer than they used to be?
Do you ever feel momentarily confused, nervous, or uncomfortable while driving?
Has a family member ever suggested that you stop driving?
Do you have low-contrast sensitivity? For example, do you have trouble seeing a gray car at dusk, a black car at night, or a white car on a snowy roadway?
Is your visual acuity on a 20/20 scale below the minimum level required by your state?

You can find the phone number of your state motor vehicle agency at www.highwayhome.com. If you answered yes to any of these questions, Mogk suggests:

Consider public transportation or share rides with friends.
Take a safe driving course designed for older drivers, like AARP's Driver Safety Program (www.aarp.org/drive or 1-888-AARP-NOW).
Drive strategically. Plan your route ahead of time, avoid left turns (which are more challenging), and avoid driving at rush hour.
Wear blue-blocking sunglasses on bright days to reduce glare. -MK