DEVELOPMENT OF SAFETY-BASED GUIDELINES FOR TREATMENT OF PAVEMENT RUTTING

The purpose of this study was to quantify how pavement rutting affects accident rates and to evaluate possible safety-based guidelines for the treatment of pavement rutting. A literature review was conducted to gain insight into the problem and to assist in developing an appropriate experimental design. Rut depth, traffic volume, and accident databases maintained by the Wisconsin Department of Transportation for undivided rural highways were then analyzed to identify statistical trends and relationships. Accidents were categorized as rut-related if the prevailing conditions could be potentially associated with the occurrence of hydroplaning. Rut depth measurements were average values for both directions of 0.15 km (0.1 mi) segments, and represent the average elevation difference between the tire paths and the high point between them. Results of the statistical analyses indicated that the defined rut-related accident rate begins to increase at a significantly greater tate as rut depths exceed 7.6 mm (0.3 inches).