Life-cycle cost analysis of rehabilitation strategies for asphalt pavements based on probabilistic models

Optimal applications of pavement rehabilitation are critical for highway agencies to allocate limited budgets. This study applied life-cycle cost (LCC) analysis, combined with probabilistic pavement performance models based on survival analysis, to evaluate the cost-effectiveness of different overlay strategies. Survival models were developed using the international roughness index (IRI) as the pavement performance indicator and considering the impact of terminal IRI values, discount rates, precipitation, and traffic volumes. The results showed that there was a significant difference in survival probabilities between thin (2 in.) and thick (5 in.) overlays, while the pavement service life was not significantly related to the overlay material type (virgin or recycled) or whether it was milled. A sequence of thin overlays was more cost-effective than their thick counterparts when traffic was not considered. However, for pavements in wet areas with annual traffic exceeding 500,000 equivalent single axle loads, thick overlays were more cost-effective.