How do visual status and age impact on driving performance as measured on a closed circuit driving track?

The aim of this study was to determine the effects of age and visual impairment on driving performance as measured on a closed circuit course. Sixty two subjects were tested, including young (< 30 years) visual normals, old (> 60 years) visual normals and old (> 60 years) subjects with early visual impairment. All subjects had a binocular visual acuity of 6/12 or better and were legally eligible to drive in Australia. Driving performance was assessed for sign detection and recognition, driving reaction times, speed estimation, and driving time. Age and early visual impairment had significant (P < 0.05) effects on sign detection and recognition, peripheral reaction times and driving time. This is of significance because all of the drivers drove regularly and were legally eligible to do so. The results also demonstrate that high contrast visual acuity is a poor predictor of the driving performance skills measured for this range of licensed drivers.