Which factors influence rider injury severity in powered two-wheeler accidents? A systematic review

The high accident risk associated with Powered Two-Wheelers (PTWs) and the limited generalizability of conclusions due to regional data disparities necessitate a comprehensive global analysis. This systematic review aims to identify the influencing factors of injury severity in PTW accidents worldwide.
This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We conducted a comprehensive review of scientific literature on PTW accidents, ultimately identifying 32 high-quality peer-reviewed papers. The findings of these studies were thoroughly examined and synthesized using a six-dimensional classification framework (encompassing road, collision, vehicle, time, human, and environmental factors).
The results indicated a consensus that the involvement of heavy vehicles, nighttime, weekends/holidays, summer, young/elderly riders, novice riders, drunk driving, frontal collisions, and running-off-the-road collisions significantly increase the severity of PTW accidents. Conversely, factors such as road classification, road geometry, intersections, weather conditions, and rider gender remain controversial, with the discrepancies likely stemming from the complex interplay of multiple variables.
This systematic review integrates findings from diverse countries, offering valuable insights for global policymakers aiming to mitigate PTW accident severity. Furthermore, we identified methodological gaps in existing research and proposed future directions, thereby providing multiple avenues for researchers engaged in road safety studies.