This paper presents the results of a comprehensive simulation study that investigated the effects of infinite elements in pavement models, eigenvalue analysis, and damping. The results provide useful insight into pavement structural responses. This is not possible from traditional static linear elastic analysis and two dimensional?finite element models developed for pavement analysis and design. A three dimensional finite element half model of an asphalt highway pavement?subgrade system was created with optimum size and boundary conditions. The model was used for simulations of the load?time history of a falling weight deflectometer impact test. The half model was validated by the results of the Green's function and showed the limitation of the use of infinite elements for pavement models. The fundamental natural frequency of 8 Hz for the an asphalt highway pavement was determined by the eigenvalue analysis using the implicit finite element code. The results of a parametric study are presented to evaluate the effects of both system damping and Rayleigh damping on pavement deflection response and backcalculated modulus values.