Correlation of Different Impact Conditions to the Injury Severity of Pedestrians in Real World Accidents

This study aimed to investigate the correlation of different impact conditions to the injury severity and impact biomechanics of pedestrians in real world accidents, and study the tolerance level with focus on head-brain of adults and children via indepth analysis and reconstructions of real world accidents. For this purpose, 188 pedestrian accident cases were selected from existing accident databases. Of which 186 cases obtained from GIDAS (German In-Depth Accident Study) documented by Accident Research Unit at Medical University Hannover in Germany, and 2 cases from Sweden. For each collected case, complete information regarding pedestrian injuries, accident cars, and crash environment was registered based on hospital clinical record and police report. In order to find the correlation of injuries observed in accident with physical parameters during a collision, reconstructions of selected 8 adultand 12 child-pedestrian cases were conducted by using pedestrian and passenger car models. The pedestrian models were generated based on the height and weight of pedestrians involved in accidents. Each car model was built up based on the corresponding accident car. The mechanical properties of the accident cars were defined based on available data from EuroNCAP tests. The correlations of calculated injury parameters with injury outcomes registered in the accident database were determined. Influences of impact conditions and pedestrian initial moving posture on HIC value were analyzed and discussed. Furthermore, the relative importance of the factors was determined according to their effects on various injury parameters. The difference of injury distribution and dynamic responses of pedestrians at various body sizes for adult and child were analyzed, which would provide background knowledge to develop safety counter-measures and protection devices.