Pavement Performance Measures

Abstract

Performance measures considered for flexible and rigid surfaced pavements and the threshold values for these measures are reported. A survey was sent to members of the Joint Technical Committee on Pavements, and 14 of 20 states responded. Performance measures for flexible pavements included international roughness index (IRI), rutting, and cracking. Performance measures for rigid pavements included IRI, patching, cracking, pop-outs, faulting, and damaged joints. For each measure, states were asked to define “good,” “fair,” and “poor” for both Inter-states and other National Highway System routes. States were asked to define their system's performance for given thresholds and to provide some information about how they collected, processed, and used the data. States use rutting and cracking to assess performance of flexible pavements. The IRI was the third-ranked measure but was consistently applied to both flexible and rigid pavements. Rutting measurements varied with the number and types of sensors, and states used five-point sensors to line sensors to three-dimensional cameras. Use of cracking as a performance measure required consensus building about definitions, measurement methods, and thresholds. Survey responses for rigid pavements were limited to jointed plain concrete because 12 of the 14 states indicated that the majority of their rigid pavements were of this type. Additional work is required for a faulting measure, because the ability to detect the joint is a function of the distance between consecutive traces. Development of definitions, methods, and thresholds is required for other rigid pavement performance measures, including patching, cracked slabs, and damaged joints.