TRB’s National Cooperative Highway Research Program (NCHRP) Report 573: Superpave Mix Design: Verifying Gyration Levels in the Ndesign Table examines the gyration levels in the Ndesign table (Table 1) of American Association of State Highway and Transportation Officials’ Standard Practice R 35, “Superpave Volumetric Design for Hot-Mix Asphalt,” in order to determine if they are correct for the four stated 20-year design traffic levels--less than 0.3 million; 0.3 million to 3 million; 3 million to 30 million; and greater than 30 million equivalent single axle loads. Appendixes to NCHRP Report 573 are online as NCHRP Web-Only Document 96.