The Association Between Visual Abilities and Objectively Measured Driving Space, Exposure, and Avoidance Among Older Drivers: A Preliminary Analysis

The objective of the study was to determine if there is a relationship between objective measures of visual function and objective measures of driving habits. The study used data from 2,131 drivers aged 65-79 enrolled in the United States based Longitudinal Research on Aging Drivers (LongROAD) study. Correlational analysis were conducted of three measures of visual function at baseline and six GPS-derived measures of driving averaged over the subsequent year. Results showed that participants had generally good visual function at the time of their enrollment. Analyses found that lower visual acuity and poorer visual perception abilities were related to a smaller driving space, lower driving exposure, and greater driving avoidance, although not for every measure. Poorer contrast sensitivity was associated with avoidance of nighttime driving and driving on high-speed roads, but was not related to driving space or exposure. This study provides evidence about how poor visual abilities can impact subsequent yearly driving. These results support other research evidence that the lower than expected crash-involvement of people with declining visual function may be related to the fact these drivers self-regulate their driving. A limitation of the study was that all significant correlations were relatively small, suggesting that other variables in addition to the ones analyzed may also be important for understanding the relationship between driving habits and visual function scores.