The Impact of Directionality on Paint Pavement Marking Retroreflectivity

Abstract

This article addresses paint centerline pavement marking retroreflectivity. The authors collect yellow centerline retroreflectivity data on two-lane highways, taking measurements in two directions. A paired t test on the data shows that there are differences and they are statistically significant. A field study is initiated to investigate the relationship between the direction the marking is painted and the retroreflectivity direction. The key result of this study is that paint centerline retroreflectivity values measured in the direction of paint striping are significantly higher than values measured in the opposite direction. Findings indicate that it is the lower retroreflectivity values of yellow centerlines (measured in the opposite direction from paint striping) that should be used to compare with the newly proposed Federal Highway Administration minimum standard because the drivers in that direction experience lower marking retroreflectivity at night. The implications for safety, for policy making, and for transportation asset management are significant.