Older Drivers Have Unique Challenge
Would you put yourself in this picture?
You and a friend are driving downtown. You stop at an intersection, wait for the traffic light to change, engage in small talk, your thoughts turning to other, more-urgent matters on your mind.
The light changes. You step on the gas. Brakes squeal. Tires skid. Horns blare. “STOP!” shrieks your friend.
Whoops.
That wasn’t the traffic light that changed. What your reflexes responded to was the blink of a lighted advertising display in a store window that caught your eye as you sat waiting for the signal to change.
How aging affects the ability to cope with competing demands on the attention is receiving increased recognition as a major contributor to traffic accidents among older motorists.
Everyone knows that vision and reflexes tend to deteriorate with age. But the latest research places increased emphasis on impaired depth perception, cognitive malfunction and inability to spot traffic signals, with so-called “night vision” skills and slowed reflexes being less important factors.
An extensive new study by researchers at the University of Utah found absolutely no statistical evidence to support the commonly held concept that older drivers see poorly at night, and thus cause an inordinate number of accidents. Nonetheless, many states, Washington included, restrict many seniors to daytime driving.
The Arizona research also casts doubt on the widely held notion that older drivers lose control of motor vehicles at higher speeds. “The odds ratio for a serious crash at highway speed vs. other speeds was no different for older drivers than for younger drivers,” said statistician Larry Cook.
Older drivers are more likely to cause crashes in crowded intersections, making left-hand turns, and failing to yield the right of way. They are almost four times as likely as younger drivers to cause a crash by failing to yield. They are one and a half times as likely to cause accidents by running a stop sign or red light.
“The study suggests older drivers have trouble spotting traffic signs and signals in a cluttered visual field at any time of day,” said Cook.
“Depth perception may also be a factor,” he said, “because we found many T-bone-type collisions (one car broadsiding another) caused by turning left and running into oncoming traffic. These are usually caused when drivers fail to judge the speed of oncoming traffic.”
Analysts concluded that testing older drivers’ depth perception and ability to see traffic signals would be a better test of skills than judging them on night vision.
In Washington, however, a state Highway Commission study last year yielded conflicting results. It found older drivers are involved in more accidents per miles traveled than other age groups. Also, analysts say that by restricting high-risk drivers to daylight hours and limiting their travel to specific destinations, the accident rate per older driver is being held to roughly the same rate as the general populace.
Dick Doane, statistical analyst for the Washington commission, told me that research on drivers over 70 showed their visual field shrinks.
Not only older drivers, but pedestrians as well, are less able to gauge distances and velocities, he said.
Certain reflexes may be diminished.
“There is some evidence older drivers may not adapt their skills to compensate for slowed reaction times and the time it takes to perform driving tasks,” said Doane.
“Older drivers may have more difficulty dividing their attention, exercising selective attention and switching attention.
“They may experience attention-based cognitive difficulties. They may have difficulty paying attention to two or three or more streams of information - this seems to be age-related in many cases.”
In Spokane, a number of the senior centers offer driver training courses designed specifically for older people. The Inland Automobile Association (AAA) also has classes. Phone 358-6921. The American Association of Retired Persons has scores of instructors statewide. Call 1-800-424-3410 or 1-206-526-7918.