How are performance-related specifications (PRS) used to ensure the long-term performance of pavement construction projects?

Performance-Related Specifications (PRS) are a type of construction specification that focuses on the desired long-term performance of the pavement, rather than simply specifying the materials and methods used to build it. They directly link payment to the predicted performance of the pavement, incentivizing contractors to build high-quality pavements that will last longer. PRS typically include performance indicators that are directly related to pavement performance, such as smoothness (measured by IRI), rutting resistance, cracking resistance, and durability. These indicators are measured during and after construction to assess the quality of the work. Payment adjustments are based on the measured values of the performance indicators. If the performance meets or exceeds the specified targets, the contractor receives full payment or even a bonus. If the performance falls below the targets, the contractor receives reduced payment or may be required to take corrective action. PRS often incorporate mechanistic-empirical (M-E) design principles to predict long-term pavement performance based on measured material properties and traffic loading. M-E design methods use engineering mechanics to calculate stresses and strains within the pavement structure, which are then related to performance indicators such as rutting and cracking. By focusing on performance, PRS give contractors more flexibility in choosing materials and methods, encouraging innovation and cost-effectiveness. They shift the risk from the agency to the contractor, as the contractor is responsible for ensuring that the pavement meets the specified performance requirements. Effective PRS require a well-defined quality control/quality assurance (QC/QA) program to ensure that the performance indicators are accurately measured and that the payment adjustments are fair and equitable. In summary, PRS are a powerful tool for ensuring the long-term performance of pavement construction projects by linking payment to predicted performance and incentivizing contractors to build high-quality pavements.