Pavement in cold region are subjected annual freeze-thaw cycles. During the spring thaw, pavement structures can become saturated and can deform considerably under normal loading. A full-scale study was conducted in the Frost Effects Reserach Facility (FERF) to quantify the rate amount of rutting of four pavement structures during thaw. Two of the sections were full-depth asphalt concrete over subgrade, and the remaining two were first frozen and then thawed. During the thaw they were loaded using a standard 80-kN axle load. Surface ruts and falling weight deflection (FWD) measurements were taken periodically. The falling weight data were used to compute the Impulse Stiffness Modulus (ISM). The measured rut depth was found to be a function of the number of load applications, the pavement cross section, the thaw depth and the ISM. A multiple regression equation was developed to predict rut depth as a function of the ISM and load applications