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Ground tire rubber (GTR) stockpiles have been increasing across the state of Florida now that GTR use in hot mix asphalt design has reduced significantly over the past decade. Therefore, the Florida Department of Transportation (FDOT) is interested in finding possible reuse applications for this material. One possible reuse would be as a blend the GTR with FDOT approved subgrades soils for roadway construction. The objective of this research was to determine the changes in the common pavement subgrade engineering behavior as various GTR percentages were added. Three subgrades were chosen based on their respective Limerock Bearing Ratio (LBR), labeled Low, Medium, and High LBR material in relation to required specifications. The 1-inch, 3/8-inch, and #40 mesh GTR sizes were used throughout testing to determine how the size of GTR particle affected the key engineering properties. GTR blend percentages corresponding to 1/2, 1, 2, and 4-inch lifts in a 12-inch subgrade were chosen, producing blends of 4, 8, 16, 24 and 32 percent by volume of GTR to Subgrade material. LBR, Constant Head Permeability, and Consolidation Tests were performed on the GTR/subgrade blends to determine the key pavement engineering design characteristics. Sieve analysis and optimum moisture content results were provided with each subgrade material by FDOT State Materials Office (SMO). The addition of GTR in any percentage decreased the density and LBR of the blends. Density decreases could be advantageous if the materials were used as backfill behind retaining structures, however the LBR decrease would not be advantageous in pavement systems. Blends with the smallest GTR, #40 mesh, did show slightly increased compressibility throughout the range of testing, however the values obtained from testing indicate almost instantaneous settlement due to the granular grain size distribution of the blends. There was no significant change in permeability with increasing GTR percentages. Overall, the results indicate that adding any percentage of GTR to the three FDOT subgrade materials would adversely affect the density and LBR, and have very little effect on the consolidation and permeability. It is recommended that further research should be conducted to evaluate whether soil/GTR blends would be suitable for low-density fill applications.