federal motor vehicle safety standards motorcycle helmets 31 pages in english this document sets forth an interpretation of the definition of motor vehicle equipment in the united states code as amended by the moving ahead for progress in the 21st century map-21 act and requests comments on two proposed changes to the motorcycle helmet safety standard federal motor vehicle safety standard fmvss no. 218. continued high levels of motorcycle related fatalities the ongoing use of novelty helmets by motorcyclists and the poor performance of these helmets in tests and crashes have prompted the agency to clarify the status of such helmets under federal law to ensure that all relevant legal requirements are readily enforceable. all helmets that are sold to and worn on the highway by motorcyclists and that based on their design and or other factors have the apparent purpose of protecting highway users are motorcycle helmets subject to the jurisdiction and standard of the national highway traffic safety administration nhtsa or agency .nhtsa is simultaneously proposing to amend its helmet standard fmvss no. 218. first nhtsa is proposing to add a definition of motorcycle helmet. second we are proposing to modify the existing performance requirements of the standard by adding a set of dimensional and compression requirements. these requirements and the associated test procedures would identify those helmets whose physical characteristics indicate that they likely cannot meet the existing performance requirements of the standard. third we are incorporating an optional alternative compliance process for manufacturers whose helmets do not comply with the proposed dimensional and compression requirements but do comply with the performance requirements and all other aspects of fmvss no. 218. nhtsa will publish a list of helmets that have complied with the alternative compliance process and can therefore be certified by their manufacturers. this document is the result of the agencys assessment of other actions that could be taken to increase further the percentage of motorcyclists who wear helmets that comply with the helmet standard.