Estimation of the Safety Effect of Pavement Condition on Rural, Two-Lane Highways

Abstract

The condition of the pavement surface can have a significant effect on highway safety. For example, skidding crashes are often related to pavement rutting, polishing, bleeding, and dirt. When transportation agencies develop paving schedules for their roadways, the agencies often base decisions on asset management condition targets but do not explicitly account for the role of pavement condition in roadway safety. The Virginia Department of Transportation began automated data collection of pavement condition with digital images and an automated crack detection methodology in 2007. Automated collection allows the department to track historical information on pavement condition; this tracking facilitates research into the effect of pavement condition on safety. Information on how pavement condition influences safety can inform paving decisions and the setting of priorities for maintenance. This study quantitatively evaluated the safety effectiveness of good pavement conditions versus deficient pavement conditions on rural, two-lane undivided highways in Virginia. The empirical Bayes method was used to find that good pavements could reduce fatal and injury crashes by 26% compared with deficient pavements, but good pavements did not have a statistically significant impact on overall crash frequency. Further analysis indicated that there was no statistically significant change in the safety benefit of improvements in pavement condition for fatal and injury crashes as the lane or shoulder width increased. The improvement of pavement condition from deficient to good offers a significant safety benefit in reducing crash severity.