A summary of the research of three aspects of the Superpave Level 1 mix design: volumetric mix design criteria for aggregates and mixes; compaction; and mix conditioning. A Delphi group process was used to select aggregate properties and specification values to be included in the Level 1 mix design procedure. Chapter 2 addresses the rationale for the election of the gyratory compactor, its relation to field control, and validation. The final chapter summarizes the research associated with the development and validation of laboratory conditioning procedures for asphalt concrete mixes. It describes the procedures used to simulate both long- and short-term aging, as well as moisture sensitivity under repeated loading.