The results of a study to determine the effects of intersection geometrics on driver performance are presented in this paper. The specific geometric features evaluated were: (1) the offset between opposing left-turn lanes, (2) the degree of right-turn lane channelization, and (3) the right-turn curb radii. The study involved the observation of left-turn and right-turn maneuvers of 200 test subjects at 11 signalized intersections with differences in the geometric features of interest. The 200 subjects were nearly equal numbers of male and female drivers in three age groups: (1) 25 to 45 years, (2) 65 to 74 years, and (3) 75 years and older. The results of the research indicated that left-turn lane offsets of zero or larger are particularly beneficial to older drivers. Also, the right-turn performance of older drivers was found to be less sensitive than that of younger drivers to the differences in right-turn lane channelization, and the effects of right-turn curb radii was similar for all age groups. Therefore, the performance of older drivers at signalized intersections would be benefitted most by increasing the offset between opposing left-turn lanes.
Samenvatting