A true mechanistic pavement design procedure should be able to correctly predict pavement response and the development of pavement distress (such as rutting and fatigue cracking) under various traffic and environmental conditions. A three-dimensional (3-D) numerical simulation procedure with realistic material models would be an effective tool that could be used to achieve such an objective. The results of a 3-D numerical simulation at the Louisiana Accelerated Loading Facility are presented. A 3-D finite-element procedure with moving wheel loads was developed for such analyses. Rate-dependent viscoplastic models were incorporated into the 3-D finite-element procedure. A creep model was used to predict rutting of the asphalt pavement. The results indicated that the 3-D finite-element procedure with viscoplastic models is capable of reflecting the pavement responses and predicting pavement rutting with reasonable accuracy.