The Effects of Vehicle Front Design Variables and Impact Speed on Lower Extremity Injury in Pedestrian Collisions Using In-Depth Accident Data

This study aimed to identify the correlations of pedestrian AIS2+ lower extremity injury risk with the vehicle front design variables and impact speed by using real-world accident data. A subsample of 404 pedestrian accident cases with AIS1+ lower extremity injuries was selected from German in-Depth Accident Study (GIDAS) database based on a defined sample criterion to conduct statistical analysis. The main variables related to severity of lower extremity injuries were determined at present study, including vehicle impact speed and vehicle design variables: lower bumper height (LBH), upper bumper height (UBH), bumper leading (BL) and bonnet leading edge height (BLEH). Firstly, analysis of variance (ANOVA) was employed to examine whether the mean values of these variables were statistically significance for pedestrian with or without AIS2+ lower extremity injuries. Furthermore, logistic regression analysis was performed to analyze associations between these predicted variables and risk of the pedestrian with AIS2+ lower extremity injury. The results revealed that the predicted variables of the impact speed, the LBH and the BLEH were statistically significant for AIS2+ lower extremity injuries. The higher impact speed, the higher LBH and BLEH correspond to a greater likelihood of suffering an AIS2+ lower extremity injury.