The Effect of Age on Motorcyclist Injury Severities in Multi-Vehicle Motorcycle Crashes: Accounting for Unobserved Heterogeneity and Insights From Out-of-Sample Prediction

This paper studies the factors affecting injury severities involving motorcyclists of different age groups (under 25, 25-55, 55 and above) based on random parameter logit model. Data collected from motorcycle crashes in UK between 2017 2020 are utilized. The motorcyclist severity outcomes categorized as follows: minor injury, severe fatal injury. results likelihood ratio tests showed that transferability multi-vehicle crash groups. modeling revealed significant variations impact among three groups, including rider characteristics (such male riders), non-motorcycle vehicle running status preceding collision, vehicle, type), roadway environmental conditions weather condition, speed limit, road temporal-related day week), crash-related types). models demonstrate existence unobserved heterogeneity for statistically variables, truck-involved, rear-end morning off-peak hours indicator under 25 group model, straight movement 25–55 passenger car sideswipe above Further, there substantial differences probabilities by comparing prediction out-of-sample simulation. emphasized importance revealing groups’ heterogeneity. highlight age-targeted policies safety.