Analysis of overweight vehicles on asphalt pavement performance using accelerated failure time models

Vehicle overweighting has been one of the key driving forces of deteriorated pavements. The overweighting characteristics that dominate the pavement performance deterioration have been inadequately investigated. This study filled such a gap by analyzing the survival time of pavement under different overweighting scenarios. The survival model was based on the accelerated failure time (AFT) formulation. For improved predictivity, an implementation of the AFT using the gradient boosting tree method was employed. All data concerned were collected from the Long-Term Pavement Performance (LTPP) program. Fatigue cracking and rutting were selected as the pavement performance indicators. Each indicator had three levels of failure thresholds to investigate the impact of overweighting on short-term, mid-term, and long-term pavement performance. The predictive performance of AFT models showed that long-term pavement performance was more dependent on overweighting than short-term pavement performance. Compared with the volume and weight of overweight vehicles, the overweighting percentage described the overweighting situation the best. Fatigue cracking was more sensitive to the overweighting percentage than rutting. Without overweighting, the average pavement fatigue life and rutting life would be extended by about 43% and 29%, respectively.