This activity provides continued funding for the development of a performance-based specification for hot-mix asphalt. A cooperative agreement for this effort was awarded to North Carolina State University in February 2008. This effort addresses the topic of performance specifications by closing the gap of how well we can test and evaluate mixes to quantify expected future performance. This project will result in the testing and analysis methodology needed to set up a performance specification for asphalt mixes. A subsequent project (awarded in Sept. 2013) will incorporate this methodology into PaveSpec, a performance related specification software for pavements. A specification that allows agencies to specify expected performance and provides the ability to reliably quantify how well that expectation is met can help move pavement construction toward an emphasis on long-term performance. The development of performance specifications reside on a continuum from performance-related specifications to performance-based specifications. Performance-related specifications describe the desired levels of key materials and construction quality characteristics that have been found to correlate with fundamental engineering properties that predict performance. Performance-based specifications describe the desired levels of fundamental engineering properties that are predictors of performance and that appear in primary prediction relationships. Over the past 10 years, the National Cooperative Highway Research Program 9-19 and the Federal Highway Administration have funded the development of hot-mix asphalt performance prediction models based on a viscoelastoplastic continuum damage theory that is based on fundamental engineering properties. The viscoelastoplastic continuum damage models are to the point where they have been validated and are now being refined and applied for use in a performance-based specification. This project is taking these advanced, fundamentally based models and applying them within a framework for a hot-mix asphalt performance-based specification. While the National Cooperative Highway Research Program 9-22 has a similar goal, the National Cooperative Highway Research Program effort was based on the Mechanistic-Empirical Design Guide models, which have significant limitations. The specification from this project will be based on three related levels of testing/analysis: (1) Comprehensive laboratory testing with rigorous analysis.(2) Simplified testing and analysis using the asphalt mixture performance tester.(3) Inexpensive and quick impact resonance testing on a project to give maximum flexibility to specifying agencies. The performance prediction capabilities of the underlying viscoelastoplastic continuum damage model are being validated with materials from the 2009 National Center for Asphalt Technology (NCAT) Test Track construction and warm-mix asphalt experimental sections in Canada, as well as materials from in-service pavements in NY, South Korea and China. This project will also evaluate materials from the asphalt project in Louisiana that will demonstrate specifications from the Second Strategic Highway Research Program (SHRP2) R07. It is expected that this specification should also work for predicting the long-term performance of warm-mix asphalt.