Reliability-based Model for Estimating Long Term Pavement Maintenance Contracts Under Performance Specifications

This paper presents a model through which the cost associated with pavement warranty in performance based maintenance contracts are analyzed and quantified. Performance based maintenance contracts are eventually getting popular among the Highway agencies.These are long term pavement warranty contracts where the contractors are responsible for maintaining the pavement condition upto a certain specified level over the period of warranty. The trend now is to award the maintenance contracts for a longer period of time, generally upto ten years or even more in some cases unlike the short warranty contracts. With the evolution of these new form of contracts, the challenge is to estimate the cost associated with these contracts for a specified performance period. Unlike the deterministic approach of cost estimation for new products, the maintenance contracts have probabilistic cost estimation approach. Since maintenance action is required when the performance threshold is exceeded, the time to failure of the product (when the performance threshold level is exceeded) is a random variable. This necessiates a different cost estimation approach for maintenance contracts of product (pavement) which is presented in this paper. The developed model can be used by the Highway Agencies as well as the contractors to estimate the cost of performing such long term pavement performance contracts based on stipulated performance criteria.