Vehicle-Terrain Interaction Modeling - Terramechanics, the study of vehicle-terrain interaction, has been used for decades to model and predict off-road vehicle mobility performance on deformable terrains. We are currently investigating the accuracy of terramechanics models when applied to small-wheeled vehicles. The lab has introduced two new pressure-sinkage models which have been shown to significantly improve the accuracy of traction models for these vehicles. Current lab facilities for this research include a vehicle terrain testbed, geotechnical soil testing equipment (in the civil engineering dept.),simulation software and a pressure-sinkage testbed. We are now developing a fluidized testbed to investigate the effect of soil volume fraction of mobility metrics.