This publication is part of WP.29. 'How it works and how to join it' series. It examines issues, progress and challenges in efforts to improve the safety and wellbeing of motorcycle riders through the use of approved motorcycle helmets. The growth in motorcycles is accompanied by an increase in serious and fatal accidents. Evidence shows that once internationally harmonized helmet regulations, such as the UN Regulation No. 22 type-approval system for helmets, are in place and laws on helmet wearing are enforced, these trends tend to reverse. In examining the relationship of income growth and national motorcycle fleet expansion, this study argues the socio-economic case for introduction of helmet regulations and their enforcement by delivering a benefit-cost analysis of taking such legislative actions.