Are there other considerations? For instance, in the design of the seats, the padded back on the seat in front of you in a school bus or in any bus, if it's there, obviously prevents somebody from colliding with something very hard and very difficult if it's a frontal collision, because the physics of a crash is such that everybody moves toward the point of impact inside the vehicle. In the case where seat belts are used, even today in motor vehicles, the other issue that comes up is the whipping effect on the head, either forward or back, or side to side, which leads to significant soft tissue injuries, depending on the person.
Are there some seat designs you're looking at that could deal with those, especially with the side to side, which would be certainly a function if a crash took place?