The Blast Event Simulations sysTem (BEST) is a synthesis tool that provides a seamless and easy-to-use coupling between existing and commercially available LS-DYNA solvers and Anthropomorphic Test Device (ATD) models for a complete sequence of explosive simulations. BEST driven simulations capture the soil/explosive/vehicle/occupant interaction. In this paper a blast simulation analysis conducted by BEST for a generic but representative vehicle is presented. The vehicle is subjected to the blast load created by an explosive buried underneath the vehicle. An ATD model is placed inside the vehicle in order to capture the loads created on the lower legs of an occupant due to the explosion. Technical details with respect to the various models engaged in the simulation are presented first. The results and the physical insight which can be gained by the analysis are discussed. A series of design modifications which add minimal weight are introduced in the vehicle structure, such as using rigid polyurethane foam material, introducing a foot rest, adding a rail stiffener on the floor, and various combinations of these design alternatives; the effects of the design changes on the forces generated on the legs of the occupant are identified through simulation. The results are analyzed in order to gain a physical insight about the design changes which improve survivability. The material presented in this paper demonstrates how simulations can be used for increasing occupant survivability and for understanding the physics which are critical for mitigating occupant injury.