A paper titled ‘A review of Powered-Two-Wheeler behaviour and safety‘ co-authored by Athanasios Theofilatos and George Yannis is now published in the International Journal of Injury Control and Safety Promotion. Current research on PTW safety is not as extensive as for other road users (passenger cars, etc.) and this research provides a critical review of research on Power-Two-Wheeler behaviour and safety with regard to data collection, methods of analysis and contributory factors, and discuss the needs for further research. Both macroscopic analyses (accident frequency, accident rates and severity) and microscopic analyses (PTW rider behaviour, interaction with other motorised traffic) are examined and discussed in this paper. The research gaps and the needs for future research are identified, discussed and put in a broad framework. When the interactions between behaviour, accident frequency/rates and severity are co-considered and co-investigated with the various contributory factors (riders, other users, road and traffic environment, vehicles), the accident and injury causes as well as the related solutions are better identified.