A major factor in pavement performance is the quality of the subgrade soil. Clay soils in particular can present great problems in pavement design due to uncertainty associated with their performance. Clay soils tend to swell and become soft when wetted and may shrink and become stiff when dried. Additives, including lime, fly ash, Portland cement, and more recently synthetics are available to successfully address these problems when mixed in the proper amounts with problem soils. These additives may be used separately or in combination, and each has construction issues related to its performance. The purpose of this study was to evaluate the quality of mixing achieved in Kansas with current construction procedures for lime-modified subgrades. Results of this study may be used to improve construction procedures to optimize performance.