The link above is to an concerning article from the Gainesville Sun today concerning motorcycle accidents occurring at a motocross event. I would love the opportunity to review the liability release documents the event sponsors have participants sign. Releases signed by minors raises issues as does releases signed by only one parent.
I suspect the great majority of participants take every precaution within their control, and use every available piece safety equipment out there; helmets, goggles, gloves, pads, boots and more.
The liability issues can arise from factors out of the control and knowledge of participants; What are track conditions like; Are riders given the opportunity to survey the track before a race; If not who does; What are the qualifications and experience of event organizers; How many racers are permitted in each race, and is the track designed to handle the numbers; Who verifies the experience of the participants and how is that done.
Motocross is a dangerous sport for the novice/beginner. Event sponsors have a duty to see that safety factors under their control are employed to prevent unnecessary collisions and crashes.