OBJECTIVE. The purpose of this study was to validate a laboratory-based driving simulator as an off-road screening tool for older adult drivers by measuring their visual attention skill, and to determine how the visual attention skill changes across time in a 45-minute simulated driving test.

METHOD. One hundred and twenty-nine community-dwelling older drivers volunteered to take part in the study. A range of driving scenarios was devised and implemented in a simulator setting to assess the driving skills of the participants. Visual attention skill, an important contributing factor to motor vehicle crashes, was assessed by the participant's reaction times to a sequence of 14 visual stimuli during the primary task of sustained driving. Repeated measures of analysis of variance (ANOVA) were undertaken to determine the effects of age and gender on the visual attention skill. Trend analysis was performed to investigate how repeated exposures to the visual stimulus affected the reaction time.

RESULTS. The visual attention skill of older drivers was found to decline with age (F_(1,126) = 42.52, p value = 0.002), whereas the effect of gender was not significant. Participants increased their speed of reaction times for the first half of the testing then slowed down during the second half.

CONCLUSION. That visual attention skill declined with age was consistent with the literature, and validated the driving simulator as an effective screening tool for older adult drivers. With rapid advancements in computer technology, the driving simulator will likely play an important role in assisting occupational therapists with off-road assessment of older drivers.