Motorcycle riders, by the very nature of their vehicles, are considerably more vulnerable to injury in an accident. The relative size and weight of a motorcycle, combined the lack of a structural frame surrounding the rider can lead to catastrophic consequences. For this reason, federal agencies and other safety organizations encourage riders to always wear a helmet when riding, even if the state in which they live do not require it. Illinois, for example, is one of only two states that has no helmet requirements whatsoever, leaving riders free to make the decision for themselves.