<div class="htmlview paragraph">Motorcyclists having fallen off their motorcycles are especially endangered if they impact on guardrails. Accident analyses show that two of three motorcyclists who impact on guardrails are severely injured. Suitable measures to protect fallen motorcyclists from impact on posts are lower W-beams or impact attenuators around the posts.</div> <div class="htmlview paragraph">Such protective measures will be cost-benefit effective, if applied on guardrail sections on which impacts of motorcyclists are considered as probable events. Such sections can only be identified retrorespectively based on accident analyses.</div>