Volumetrics describe the relationship between the mass of matterand the volume it occupies. Density, a quotient of mass to volume,is the most commonly used parameter for HMA mix design, qualityassurance, and quality acceptance. The proper use of density measurementsdepends strongly upon the ability to accurately and preciselymeasure both the desired volume and mass of the mixture. Threeindependent studies were conducted to investigate the variabilityof density measurements (i.e., various measurements of bulk specificgravities), control of volumetric proportions during construction,and the influence of in-place densities on pavement performance.