Horizontal Curve Driving Performance and Safety Affected by Road Geometry and Lead Vehicle

Abstract

To help enhance safety and reduce crashes occurred on horizontal curved roads, it is important to understand their potential causes. The study reported in this paper aimed to examine the effects of road geometry (i.e., road curvature and curve direction) and lead vehicle on horizontal curve driving performance. Twenty-four participants performed two driving tasks (i.e., car-following and free- flow conditions) in simulated driving scenarios including curved roads in both right and left directions to measure their driving performance (e.g., speed, lane position, steering wheel angle, and time and distance headways). The results showed that road curvature affected driving performance, especially in mean speed, variability of lane-keeping performance, and headway. Moreover, the mean speed was affected by both road curvature and whether a lead vehicle existed. Findings from this study provide empirical data that can be used for driving safety on horizontal curved roads.