Visibility Effectiveness of Hemisphere and Corner Cube Retroreflective Pavement Markers on Curved Roads

Abstract

This study was conducted to investigate the visibility effectiveness of hemisphere and corner cube pavement markers on various curved road driving conditions. The study consisted of a field experiment to investigate visual threshold and an evaluation study to investigate visibility effectiveness. In the field experiment, a U-shaped test track with a curvature of 30 m radius was set up to investigate the visibility threshold. Two marker types, the hemisphere and the corner cube, and two directional driving conditions, right-turn and left-turn conditions, were considered. The results indicate that there is no difference between marker types, but there are differences between turning directions. The left turn has a significantly higher value and is therefore determined to be the resultant visual threshold. The resultant visual threshold is