This paper presents two test procedures, the constant load and haversine load, for determining the viscoelastic properties of asphalt concrete using the indirect tension (diametral compression) test. Equations for calculating the creep compliance and complex compliance from test result are derived. Locations of change in length measurements are recommended. Details of data reduction algorithms and the pros and cons of the two procedures are discussed. A series of laboratory tests were conducted on two groups of specimens to illustrate the methodology and verify the analysis.