Abstract
Visual search patterns and motor control movements were measured on the road, and curve psychophysics, information processing abilities and susceptibility to visual illusions were studied in the laboratory. The major results of the study were traditional measures of curve length and central degree were unrelated to accident statistics, drivers perception of curvature, and drivers tendencies to decelerate before the curve. Two driver-performance indexes of curvature were developed and were found to de significantly related to accidents on curves.