The Superpave volumetric mix design system, developed by SHRP in the 1990s, has continued to gain widespread acceptance across the United States. Although it is widely believed to be an improvement over past mix design systems, it does have an inherent flaw. It does not include a performance test to assess HMA's resistance to rutting, fatigue, or low temperature cracking. With the development and implementation of newer performance test specifications, it is an appropriate time to work on integrating a performance based test for construction specifications. Rather than being based on material properties or construction practices, the payment for an HMA pavement could then be based primarily on the performance based specification. The results of this study indicate that although the APA works well as the pass/fail criterion used by state agencies, the variability of APA cycles to failure make it impractical to base a rut prediction model on data obtained from it.