Effects of longitudinal pavement edgeline condition on driver lane deviation

Single vehicle crashes, particularly those classified as run-off-the-road, are very common on two-lane rural highways. One method to potentially reduce such crashes is to provide additional driver information in the form of wider longitudinal edgeline pavement markings. However, since these markings deteriorate over time, the primary objective of this research was to study the effects of longitudinal edgeline pavement markings with varying deterioration levels and widths and to assess a driver's ability to maintain lane position. The University of Idaho's driving simulator was used to examine these effects by incorporating different marking deterioration percentages and roadway geometries on a two-lane rural highway environment. Two different pavement marking widths (4 and 6 inch) and four different deterioration levels (0%, 25%, 50%, and 75%) were assessed in daytime and nighttime conditions as part of this study. The results determined that while wider 6-in longitudinal edgeline pavement markings compared with standard four inch edgeline markings did not cause any significant changes in driver lane deviation during the day, statistically significant differences were observed in nighttime driving conditions. Drivers consistently maintained a lane position that slightly favored the edgeline side throughout the study and increasingly shifted away from the centerline as edgeline deterioration worsened.