SUNDAY, Oct. 26, 2003 (HealthDayNews) -- The car accidents, both in July, occurred thousands of miles apart but bore stunning similarities.
In the first, an 86-year-old driver ploughed through a farmers' market in Santa Monica, Calif., killing 10 shoppers and injuring at least 35.
Weeks later, a 79-year-old Flagler Beach, Fla., man lost control of his car and injured three people, also at a local farmers' market.
The tragedies immediately re-ignited the national debate about elderly drivers -- and probably triggered much discussion within families. Is Dad too old to drive? Should we persuade Grandma to give up her car?
People 70 and older make up just nine percent of the U.S. population, but account for almost 14 percent of all traffic fatalities annually, according to the National Highway Traffic Safety Administration.
By 2020, one of five Americans will be over age 65, according to the National Institute on Aging, and most of them will probably hold a driver's license.
Yet age alone isn't a reason to take away the privilege of driving.
"It's really your functional ability that matters," says Cynthia Owsley, a researcher at the University of Alabama at Birmingham, who has studied the effects of aging.
"If you are 90 and have very good functional capabilities -- your vision and your thinking and memory and physical functioning are in good shape -- there is no reason to take away your license just because you are 90," she says.
Geriatric experts say the wide variation in the general health and fitness of seniors makes it impossible to suggest a cut-off age for driving fitness. A variety of conditions play a role, including vision, motor skills, reaction time, the use of medications, and cognitive functioning -- with a lack of the latter perhaps to blame when older drivers mix up the brake and the gas pedals.
But families no longer must act alone when it's time to decide whether an aging relative should give up his keys.
The American Medical Association is strongly encouraging its doctors to take a more aggressive role in helping to decide when patients are too old or infirm to drive. This should take some of the onus off family members -- and perhaps reduce resentment from older drivers who would hear the suggestion from a physician they respect.
To help doctors make that decision, the AMA has posted on its Web site a new 226-page guide, which includes a checklist to test a patient's vision and motor skills.
The doctors also get tips on how best to persuade unfit drivers to give up the wheel.
Evaluations to determine fitness for driving are offered at rehabilitation centers across the country, including the Rehabilitation Institute of Chicago. While the program there isn't designed specifically for older drivers, it tests for potential problems that may plague older drivers, such as memory, vision and decreased strength, says Janet Bischof-Rosario, an occupational therapist affiliated with the program.
It also includes a two-hour road evaluation of the driver's skills.
While some of the signs that an aging motorist should quit driving are fairly clear, such as severely impaired eyesight, it's still a tough call, Bischof-Rosario concedes.
Family members should pay attention to certain clues, such as someone who's having too many fender-benders, or taking too long to complete what should be a brief errand, suggesting she may be getting lost.
Enlisting outside help -- like a family doctor -- can make it easier to determine if an older person is no longer capable of driving, says Melvin Shipp, an optometrist and researcher at the University of Alabama at Birmingham, who has studied the link between aging and driving.
"It's sometimes easier if you have a professional, someone independent, tell the person" he needs to stop driving, he says.
Other geriatric experts have studied the effects of age-related problems, such as cataracts, and whether correcting them helps.
Drivers with cataracts "may not see the lane demarcations, so they drift to another lane," says Owsley.
She led a study that followed 277 older people for up to six years and found that the 174 people who had cataract surgery had a 50 percent reduction in crashes, compared with the 103 who didn't have cataracts removed.
"The reason it is an important finding is that by the time you are 75, about half the population has what we call a clinically significant cataract that can interfere with vision," she says.
Some groups, including AARP, suggest driving refresher classes for older motorists.
But Owsley says research about the benefits of such programs is less than encouraging, with many studies showing no decline in crashes among those who take the courses.
But she wouldn't recommend against the classes if they are available, because drivers may gain a greater awareness of safety and avoid crash-prone settings, such as rush-hour traffic.
The National Institute on Aging says there are certain features that can make it easier for an older person to drive a car. They include power steering, power brakes, an automatic transmission, and larger mirrors.
The institute also suggests keeping the headlights on at all times and making sure they're clean and aligned. Also, check windshield wiper blades often, and use a rear-window defroster to keep that window clear at all times.
For details about how age affects driving, see the National Institute on Aging. For tips for older drivers, see the National Highway Traffic Safety Administration. And check with the American Medical Association for more on the recommendations for optimizing safety for older drivers.