<p><p><strong>Reference(s):</strong></p><p><em>Christopher et al. (2010)</em></p><p><strong>Method Summary</strong></p><p>Documenting roughness, rutting, and other pavement distresses is a common procedure for determining the performance of a pavement system. Methods such as AASHTO PP 37-04 or equivalent state methods can be used to determine the International Roughness Index (IRI) of the pavement. Surveys of the pavement can be taken to observe and predict the performance of a pavement.</p><p><strong>Accuracy and Precision</strong></p><p>The accuracy and precision of the program will be determined by the thoroughness of the pavement management system program.</p><p><strong>Adequacy of Coverage</strong></p><p>Adequacy and coverage will depend on the frequency of tests. A conventional distress survey will not determine problems with the pavement system until there is a failure. Non-destructive structural tests (FWD and LFWD) in addition to the distress observations can identify problem areas (Christopher et al. 2010).</p><p><strong>Implementation Requirements </strong></p><p>Determining pavement serviceability with the Present Serviceability Index (PSI) or IRI method is a straightforward method that can be implemented easily. To get the full benefit of determining pavement serviceability, the use of a pavement management system is important. The actual implementation of a pavement management system is a laborious task; however it is assumed that most states have an established pavement management system.</p><p><strong>General Comments</strong></p><p>The Empirical Design Method incorporates the Present Serviceability Rating (PSR) and the PSI. The Mechanistic-Empirical Design Method incorporates the IRI into the damage predicted by the damage models, and is a well-accepted method of monitoring pavement performance. Both serviceability ratings (IRI and PSI) are important to determining the effectiveness and accuracy of a design.</p></p>