Two sled systems capable of producing structural intrusion in the footwell region of an automobile have been developed. The first, System A, provides translational toepan intrusion using actuator pistons to drive the footwell structure of the test buck. These actuator pistons are coupled to the hydraulic decelerator of the test sled and are powered by hydraulic energy from the impact event. Resulting footwell intrusion is characterized using a toepan pulse analogous to the acceleration pulse used to characterize sled and vehicle decelerations.Sled tests with System A indicate that it is capable of accurately and repeatably simulating toepan/floorpan intrusion into the occupant footwell. Test results, including a comparison of lower extremity response between intrusion sled tests and no intrusion sled tests, indicate that this system is capable of repeatable, controlled structural intrusion during a sled test impact. Test results also suggest that lower extremity forcing during footwell intrusion is significantly larger than such forcing with no intrusion and that response and risk of injury for occupants in frontal or frontal-offset crashes are more severe. To expand the available range of simulated footwell intrusion, the design of a second intrusion test system, System B, is presented. This system includes toepan translation, rotation and combined translation/rotation motions as well as an expanded range of toepan accelerations. System B also allows the independent motion of the left and right toepan thus enabling the simulation of yawing motions in the occupant footwell.