Projection kinematics of pedestrian impacted by low-long-fronted vehicles based on simulation and China’s in-depth accident database

In the analysis of vehicle-pedestrian accidents, the movement traces of pedestrian can be used to analyze vehicle’s impact speed which is one of the most important parameters for accident reconstruction. Low-long-fronted vehicle is the most common vehicle type involved in pedestrian accidents. This study focused on the kinematics when a pedestrian was impacted by low-long-fronted vehicles. Firstly, simulation models of vehicle-pedestrian impact were constructed based on the accident simulation software PC-Crash, and various data were obtained by means of simulation tests. Secondly, pedestrian projection kinematics was analyzed in-depth from the view of the relationships between impact speed and other parameters such as throw distance, apogee height, rotation number, launch angle, etc. Especially, “classical wrap projection” and “enhanced wrap projection” were originally defined for the first time. Thirdly, a new pedestrian throw distance formula was proposed with a power function based on the simulation results. Fourthly, 51 real-world accidents (including 23 accidents with surveillance videos) from China’s in-depth accident database NAIS (National Automobile Accident Investigation System) were used to verify the simulation results and the newly developed formula. Finally, the new model was compared with other models reported in the literature. The results are useful for forensic investigation of pedestrian accidents.