Because these tasks take attention away from driving, older drivers' slow performance puts them at greater risk of being involved in accidents. To help keep all motorists safe, developers of high-tech navigation systems products must be sure to include older subjects in safety and usability evaluations of the devices, says senior research scientist Paul Green. Green reviewed the results of several UMTRI studies on age and driver performance at the Association for the Advancement of Automotive Medicine Conference on Aging on Driving.
 

Even the basic task of "plain old driving" is more difficult for older drivers than for younger ones, UMTRI studies show. "However, much larger differences are often found when common electronics tasks are added-such as responding to warnings, reading complex displays, and entering data," says Green. "This difference is of particular concern because the time older drivers take to complete some tasks is on the order of minutes, and distractions of that duration can expose drivers to unacceptable levels of risk."

Many of the UMTRI studies were done using the institute's driving simulator . To study the demands of ordinary driving, for example, the researchers had subjects "drive" straight and curvy roads in the simulator, keeping their eyes closed as much as possible and pressing a button whenever they felt they needed a 0.5 second glimpse of the road to continue driving safely. The rationale for this experiment is that the more demanding the driving situation, the more often the driver needs to look at the road. By recording the amount of time subjects keep their eyes open, researchers can assess the visual demand of driving. In experiments of this type, visual demand generally increased with age, with the value for older drivers being 15 percent-50 percent greater than for younger drivers. The higher visual demand means that older drivers have much less time to take their eyes off the road and pay attention to gadgets inside the car.
 

In other experiments, drivers in a mock vehicle watched a typical expressway scene, with road signs, passing cars and flashing brake lights. While scanning the road as they would in normal driving, the drivers also had to watch for a triangle-shaped warning icon on a windshield display and press a key whenever they noticed the icon. On average, older drivers took 40 percent longer to respond to warnings than younger drivers.

UMTRI researchers also studied drivers as they used electronic maps and entered and retrieved destinations into a navigation system. They found that:

Older drivers took 33 percent-100 percent longer than younger drivers to perform map-reading tasks while driving in the simulator. They also made more errors in map interpretation. The more difficult the task, the greater the difference between older and younger drivers.

In an actual vehicle on the road, the difference was even greater, with older drivers taking 40 percent-70 percent longer than younger drivers to complete the same map reading tasks. Again, the difference increased as tasks became more difficult.

Even when parked, older drivers took almost 80 percent more time than younger drivers to enter information in a navigation system.
 
"As these studies have shown, older drivers experience considerably more difficulty in completing telematics tasks," Green notes. The solution is not to keep older drivers off the roads, because the resulting loss of mobility and independence can be as devastating as a serious illness. Instead, "it is critical that motor vehicles and telematics products for vehicles be designed so that they are safe and easy to use for elderly drivers," Green says. "If the older drivers are able to complete a task safely and easily, then other drivers will be able to as well."