Pavement Performance Measures: How States See Good/Fair/Poor
This paper reports on performance measures being considered for flexible and rigid surfaced pavements and the threshold values for these measures. A survey was sent to members of the Joint Technical Committee on Pavements and 14 of 20 responded. The performance measures for flexible pavements included International Roughness Index (IRI), rutting and cracking. The performance measures for rigid pavements included IRI, patching, cracking, popouts, faulting, and damaged joints. For each measure, states were asked to define good, fair, and poor both for interstates and other National Highway System (NHS) routes. They were asked to define their system’s performance for given thresholds and for some information about how they collect, process, and use the data. States use rutting and cracking to assess performance of flexible pavements. IRI was the third ranked measure, but it is the measure that is consistently applied to both flexible and rigid pavements. Rutting measurements vary among the states due to the differing methods used to gather the data. These methods include 3-point sensors, 5-point sensors, line lasers, and 3-D cameras. Use of cracking as a performance measure will require consensus building about definitions, measurement methods, and thresholds. The 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 are of this type. Additional work will be 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 will be required for other rigid pavement performance measures including patching, cracked slabs, and damaged joints.