Older drivers at high crash risk are 'more distractible'

Older drivers who show limitations on the "Useful Field of View" (UFOV) test make more driving errors when distracted, suggests the new research, led by Joanne M. Wood, PhD, FAAO, of Queensland University of Technology, Brisbane, Australia. "This finding provides a basis for predicting those older adults who will be more distractible on the road, and therefore also those who might benefit most from minimizing distraction while driving," the researchers write.

UFOV Predicts Driving Problems Related to Distraction The study included 92 drivers, average age 74 years, who underwent the computerized UFOV test. Useful field of view is defined as "the area over which a person can extract information in a single glance without moving his or her head or eye." Drivers with limitations in UFOV are more likely to have problems in demanding driving situations, with an increased risk of crashes.

After the UFOV test, the drivers performed a closed-course driving test three times. On two occasions, they did the driving test with in-car visual or auditory distracters, consisting of simple math problems presented on a video screen or audio speaker.

Drivers who had limitations in UFOV were most likely to have problems on the driving test related to both visual and auditory distracters. They also took longer to complete the driving test -- possibly reflecting slower driving speeds, which are common among older drivers.

In particular, drivers who scored lower on the "selective attention" subtest of the UFOV had decreased performance on the driving test in the presence of distracters. Drivers with lower scores for selective attention were also more likely to be rated at high crash risk on the UFOV. "This finding suggests that the driving problems elicited in the presence of visual or auditory distracters are greatest for those who are rated at most risk for crashing overall," the researchers write.

In contrast, older drivers who did better on the selective attention subtest had better overall performance on the driving test, even with distracters. The selective attention subtest was a better predictor of performance on the driving test than the other two UFOV subtests (visual processing speed and selective attention).

Older Drivers at Risk Should Minimize Distractions Previous research has shown that the UFOV test is highly effective in predicting crash risk among older adults, with or without vision problems. The new study suggests that distractibility is an important contributor to problems in driving performance and to crash risk predicted by the UFOV test. That's consistent with recent research on the effects of increased distraction while driving -- especially for auditory distractions and cell phone use in cars.

"Our results have important implications for the design of in-vehicle devices, such as satellite navigation devices and mobile phones (even when hands free)," Dr Wood and coauthors write. "The effects of distracters are likely to be exacerbated as the driving environment becomes increasingly complex." They believe that older drivers with "more extensive constriction" of their UFOV should be warned of their possible increased risk of driving errors -- and perhaps especially to minimize distractions while driving.

"The result is consistent with the observation that many have made that as you age you find in-vehicle distractions (like a radio or noisy conversation) to be more annoying," comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science. He adds, "It certainly raises even more questions about the wisdom of in-vehicle screen displays and cell phone use!"