Identification and Determination of Distress Levels and Rehabilitation Cycles

More resources are used to preserve and rehabilitate the existing pavements than to build new ones. In order for the Transportation Cabinet to maintain the Commonwealth's pavements in an acceptable condition of service, it is estimated by the pavement management section that a major increase in funding is necessary. The thresholds of pavement performance on which resurfacing and rehabilitation decisions are based have great impact on funding at the network level and proj ect prioritization. If treatments are applied too late, pavements may accelerate deterioration and result in more expensive rehabilitation later. On the other hand, if treatments are applied too early, the remaining capacity of existing pavements is not fully used. In Kentucky, the distress levels of pavements are reflected by their condition points, but they do not include the detailed information concerning the types and severity of different distresses. The new pavement design guide under way, the 2002 "Guide for Design of New and Rehabilitated Pavement Structures," aims to improve the current design practices. It allows the designer to change pavement design inputs and evaluate the resulting change in pavement performance. This predicted performance must then be compared to acceptable levels within an agency to evaluate the effectiveness of a particular design. In addition, it is desirable that the models used to predict specific distresses are calibrated to local conditions and materials. To use the new design procedure, the distress data in Kentucky need to be recorded in more detail, critical distress thresholds need to be defined, and pavement performance models need to be calibrated. Then, rehab cycles can be predicted for different treatments and an optimum one can be identified.