Subgrade soil characterization in flexible pavement design is necessary for estimating the structural capacity of flexible pavements and then determining tbe pavement layer thicknesses. Several non-linear and linear models have been used to characterize the subgrade soils. The current bulk and deviatoric stress models have limited applications since they are essentially developed for a particular soil type. Few other models are restricted by the multiple collinearity problems in the regression analysis. A regression model with confining and deviatoric stresses as attributes is adopted in this paper to analyze the repeated load triaxial test results. This model is simple, easy to analyze the repeated load triaixial test results and does not have any structural type collinearity problems. This paper presents the regression model analysis results on different subgrade soils including mixed soil types. The repeated load triaxial tests conducted on granular, cohesive and mixed soil types at various moisture content levels are first analyzed to determine the model constants. The model constants are then correlated with the basic soil properties. The correlations are evaluated in their reliability in predicting the resilient properties of the same subgrade soils. This evaluation, which is fairly successful, showed that this approach can be used to predict the resilient properties of similar type soils. This approach will save significant project costs since core sampling and resilient modulus testing tasks can be averted.