The combined effect of vehicle frontal design, speed reduction, autonomous emergency braking and helmet use in reducing real life bicycle injuries

Vulnerable road users as bicyclists and pedestrians account for a significant share of fatalities and serious injuries in the road transport system. Traditionally, the protection for bicyclists has been addressed by speed management and separating vulnerable road users from motorized traffic. Also, the use of bicycle helmet has been prompted and regulated in some countries. Pedestrian protection by improving the car fontal design has been around since the late 1990th and has proven to be effective in reducing injury risk on pedestrians although the benefits for bicyclists have not yet been evaluated on real world data. Pedestrian detection with Autonomous Emergency Braking (AEB) has also been introduced on the market to prevent and mitigate pedestrian and bicyclist injuries. The purpose of this study was to evaluate the effect of the different interventions promoting safety for vulnerable road users. Emergency hospital reports from approximately 2 000 bicyclists and 1 200 pedestrians between Jan 1st 2003 and March 2014 were included in the study. Hospital reports including injury diagnosis were combined with police data and the vehicle registry in order to obtain detailed vehicle information. Euro NCAP pedestrian test score was correlated with real-life pedestrian and bicyclist injuries. The results showed that on pedestrians, large injury reductions were found comparing low scoring cars (1-9 p) in the Euro NCAP pedestrian test to high scoring cars (>18 p). Also for bicyclists significant injury reductions were found. Focusing on bicyclistrs injury level, large reductions were found on all body regions, with the highest reduction on head injuries. The calculated combined effect of speed-reduction, helmet-use and car frontal design was 79%. When the effect of AEB was added, the risk of long term disability decreased by more than 90%.