Visual Attention and Roadway Landmark Identification in At-Risk Older Drivers,

Driving is a complex task that makes high demands on visual processing capacity. Reduction of visual attention and processing speed are risk factors for car crash involvement in older drivers. Impairment of these visual functions can affect driver safety by impairing the ability to search for information in a cluttered panorama that includes traffic signals and road signs. The purpose of the current study was to examine the extent to which on-road landmark identification during the driving task is predicted by off-road measures of visual attention. The study shows that scores on a test of selective visual attention correlated with ability to identify landmarks (restaurants) on a commercial highway, yet visual processing speed and divided attention showed no significant correlation. Moreover, ability to identify safety signs did not correlate with any of the visual measures. Several factors may have affected the percentage of landmarks (signs and restaurants) identified. One factor is the variability of ambient traffic, which causes a variation of driver workload, which in turn affects the ability to search the roadway for visual targets. Also, some drivers tended to call out indiscriminately every landmark they encountered, which would tend to increase their percent correct responses. In future analyses, the theory of signal detection will be applied to address this response bias.