In Huff v. Wilkins (2006) 138 Cal.App.4th 732 [41 Cal.Rptr.3d 754] plaintiff was injured when the all terrain vehicle (ATV) he was riding on public land collided with an ATV being operated by the 14-year-old defendant without adult supervision.  Plaintiff sued the boy and his father for negligence, alleging that they violated a Vehicle Code provision that prohibits anyone under 18 years of age from operating an ATV on public land without adult supervision or completion of a safety training course.  The Imperial County Superior Court granted summary judgment for defendants citing Distefano v. Forester (2001) 85 Cal.App.4th 1249 [102 Cal.Rptr.2d 813], which found collision to be an inherent risk of off-roading and applied primary assumption of the risk as adopted by the California Supreme Court in Knight v. Jewett (1992) 3 Cal.4th 296 [834 P.2d 696].  On appeal, the Fourth District reversed, finding that violation of the safety regulation could have increased the inherent risks of the sport, and remanded the matter for a hearing by the trial court to determine whether it did.