The Asphalt Pavement Analyzer (APA) has been widely adopted as a straightforward method to evaluate HMA rutting potential in mix design and QC/QA applications. However, the APA test does not yield a fundamental material property that can be used with appropriate materials characterization and distress prediction models to predict rutting performance. A key issue with the APA (or with any other method intended for this purpose, including other types of loaded wheel testers and simple strength tests) is the degree to which the relationship between the APA's test results and actual field performance depends on specific project-associated factors such as aggregate properties, mix design type, traffic level, and traffic speed.

The objectives of this project were to (1) evaluate the Asphalt Pavement Analyzer to determine its suitability as a general method of predicting rutting potential and for use in field quality control and quality acceptance operations and (2) compare the effectiveness of the Asphalt Pavement Analyzer with that of other loaded wheel testers and a simple strength test, such as the one identified through Task C of NCHRP Project 9-19, Superpave Support and Performance Models Management.

The final report has been published as NCHRP Report 508, Accelerated Laboratory Rutting Tests: Evaluation of the Asphalt Pavement Analyzer.