Vehicle-induced ruts can cause severe adverse effects on soil and vegetation and reduce a vehicle's mobility potential. Vehicle turning factors including turning radius, velocity, and dynamic weight effects were integrated into the Vehicle Terrain Interaction (VTI) terrain mechanics model to predict rut formation during vehicle turning operations on yielding soils. In the modified VTI model, the resultant force on a single tire is a dynamic variable correlated with the vehicle's dynamic weight, velocity, and turning radius. Field tests using an eight-wheeled light armored vehicle (LAV) were conducted, and the results were analyzed and implemented in a modified VTI sinkage model for turning. The LAV was operated at varying velocities during spiral-pattern turn testing to obtain continuously decreasing radii rutting results. The results of the LAV field tests were analyzed with predictions from the modified VTI, and the conclusion shows that the modified model can be used to predict the influence of turning on soil rutting. Rut depths for both vehicle tracks were predicted for turning operations. Results show a tremendous improvement in prediction of rut depth using the modified VTI model, which includes the effect of turning.