Unified pavement distress index for managing flexible pavements

One of the innovative approaches for maintaining and rehabilitating the nation's highways is to develop and implement some form of pavement management system (PMS). This paper documents results of a survey on PMS use in the United States. In addition, a simple method for a PMS based on priority ranking is presented. The model uses the theory of fuzzy sets to process the information obtained from a typical pavement condition survey. An index, called unified pavement distress index (UPDI), is defined and used to measure the pavement distress condition. The new approach is presented in a few key elements: guidelines for rating of six types of distresses, weights among the different types of distresses, fuzzy-set representations of the linguistic grades and fuzzy mathematics, and the definition of UPDI and its use in a pavement data base. An example is presented to show how the new approach can be employed to analyze data bases generated from a pavement condition survey. While the proposed approach has shown its potential in the example application, more positive feedbacks from large-scale field tests are needed to demonstrate its reliability and ease of use.