The research was based on the hypothesis that some property of the asphalt mixture available during compaction in the Superpave Gyratory Compactor (SGC) was related to rutting resistance of the mix. The research found that properties during SGC compaction, such as compaction slope, appeared to be somewhat related to aggregate characteristics (gradation, particle shape/texture, and angularity) but were insentive to asphalt binder characteristics such as asphalt binder content and grade (stiffness). In a separate study discoverd that the indirect tensile strength of an asphalt mixture was related to mixture cohesion in the Mohr-Coulumb failure theory, and was related to rutting potential. Unlike the SGC properties, the indirect tensile strength was sensitive to asphalt binder stiffness.