IRI deterioration model for asphalt concrete pavements: capturing performance improvements over time

Abstract

Pavement deterioration models are an essential component of performance-based management of transportation infrastructure. This study aims to improve existing techniques by developing a deterioration model that captures the effect of pavement performance improvement across time. By using an iterative reweighted least squares approach, the model is applied to publicly available roughness data of asphalt concrete pavements collected as part of FHWA’s Long-Term Pavement Performance (LTPP) program. The results of the case study demonstrate that pavement performance has significantly improved over time. The parametric model suggests that the expected serviceable life of a typical asphalt pavement built in 1970 is only 22 years whereas a section with identical structural capacity and traffic loading built in 2000 achieves a 31-year serviceable life. These discrepancies highlight the importance of incorporating the construction year of a pavement as another explanatory factor within pavement deterioration models. The proposed model accounts for biases in existing approaches and will allow decision-makers to improve their current deterioration models and produce more optimal resource allocation strategies for existing pavement assets.