Motorcycle Helmet Standards – Harmonisation and Specialisation?

There are a number of major motorcycle helmet standards, e.g. AS/NZS 1698, DOT, JIS T 8133, Snell M2010 and UN/ECE 22. With international trade agreements, on-line purchasing, and motorcycling growth there is a need to assess whether there is scope for harmonising motorcycle helmet standards as well as specialising standards for specific environments. This paper will compare and contrast standards requirements and consider opportunities for improvements and international harmonisation. A desktop review of standards, motorcycle helmet and relevant biomechanical literature was undertaken. The results of impact performance tests on 31 helmets that met at least AS/NZS 1698 and combinations of other standards were assessed by standard certification. Tests included 2.5m flat and hazard anvil impacts with an International Organization for Standardization (ISO) “M” headform. Peak headform acceleration was measured. Results from oblique impact tests on motorcycle helmets were evaluated in terms of identifying the benefits of such a test. The test rig consisted of a Hybrid III head and neck falling on guided rails onto the top of a powered striker plate. Tests were conducted up to a drop height of 1.5 m and a horizontal speed of 35 km/h. Linear and angular headform acceleration were evaluated. There are many commonalities between each standard, but there are subtle to substantial differences also. All standards have tests of acceleration management, retention system strength and stability. No standard has a true oblique impact test and chin bar assessment is varied. There are no studies that compare the performance of helmets in real world crashes by standard certification. There were few significant differences in helmet performance in lab tests by standard certification, particularly when only full-face helmets were included in the analysis. There was an overall correlation (Pearson Correlation = 0.60 (p<0.01)) between helmet mass and impact performance. Average maximum linear and angular headform accelerations for four helmets in oblique impact tests were 150g (SD=30) and 9.5rad/s² (SD=3.3), respectively. Motorcycle helmets have been shown to reduce the risk of death by 42% and head injury by 69%. Mild traumatic brain injury appears to be the prevalent form of injury suffered by helmeted motorcyclists. Although there are differences between each standard, some potentially would make at best only a marginal difference in a crash. Some, such as Snell M2010 appear to be associated with heavier helmets. Oblique helmet testing can identify performance differences between helmets that are related to injury mechanisms not assessed directly by current standards. The climate and road environment are issues that need to be considered and might lead to helmet specialisation as found in JIS T 8133. In other words, operators of low powered motorcycles in hot and humid climates might have a helmet certified to a different part of a common standard compared to operators of high powered motorcycles ridden at speed on major roads. Also critical to the motorcyclists is the incorporation of a quality control system including batch testing. These issues indicate opportunities exist for harmonisation, specialisation and improvement in motorcycle helmet standards that will benefit motorcyclists, government, trade and road safety groups.