Optimal Thresholds for Pavement Preventive Maintenance Treatments Using LTPP Data

Abstract

One obstacle to the optimal time for pavement maintenance treatments based on the expected performance or cost-effectiveness is the lack of posttreatment performance models at different timings. This study first summarized the current effectiveness/cost-effectiveness evaluation methods. Then, the posttreatment performance model was established based on the pretreatment performance model and other factors such as traffic and environment. By incorporating the incremental posttreatment performance models into the effectiveness evaluation, an optimization method was developed to calculate the dynamic effectiveness/cost-effectiveness and to select the optimal performance threshold. Investigation of 243 sections from the long-term pavement performance (LTPP) database showed that when the pavement deteriorated very fast, an early age treatment was recommended, whereas when the pavement condition was good and the deterioration rate was not fast, a higher optimized international roughness index (IRI) threshold was recommended. In addition, the optimal IRI thresholds for fog seal and crack seal are lower than those of thin overlay, chip seal, and slurry seal, indicating that it is more effective or cost-effective to apply fog seal and crack seal treatments at a relatively early age.