- Aggregate gradations for quality hot-mix asphalt (HMA) should be selected to minimize sensitivity to the variability in asphalt content and gradation during production. In this paper, Job Mix Formulas (JMF) of known performance were obtained from various agencies. These JMF were analyzed in an effort to establish relationships, criteria, and guidelines to facilitate the identification of high quality aggregate gradations, based on a demonstrated record of good in-service pavement performance on fairly high traffic highways. The results from this study provide a tentative approach for the selection of aggregate gradations for HMA. The coarse aggregate gradations for these asphalt mixtures were defined by a regression power law equation according to the effective maximum size of the aggregate blend. Similar analyses of fine aggregate gradations produced groupings according to the maximum size aggregate and percent passing the 4.75 mm sieve.