TRB Transportation Research Circular E-C105: Factors Affecting Compaction of Asphalt Pavements includes invited papers that were presented at a January 2005 workshop that explored asphalt practitioners’ concerns related to specifying and achieving density during hot-mix asphalt (HMA) pavement construction. Issues covered by the papers include optimizing HMA construction temperatures, advances in compaction equipment, longitudinal joint density, and incentives and disincentives for construction quality.