A Study of Adult Pedestrian Head Impact Conditions and Injury Risks in Passenger Car Collisions Based on Real-World Accident Data

Abstract

Objective: The aim of the current study was to study the kinematics of adult pedestrians and assess head injury risks based on real-world accidents.

Methods: A total of 43 passenger car versus pedestrian accidents, in which the pedestrian's head impacted the windscreen, were selected from accident databases for simulation study. According to real-world accident investigation, accident reconstructions were conducted using multibody system (MBS) pedestrian and car models under MADYMO environment (Strasbourg University) to calculate head impact conditions in terms of head impact velocity, head position, and head orientation. Pedestrian head impact conditions from MADYMO simulation results were then used to set the initial conditions in a simulation of a head striking a windscreen using finite element (FE) approach.

Results: The results showed strong correlations between vehicle impact velocity and head contact time, throw distance, and head impact velocity using a quadratic regression model. In the selected samples, the results indicated that Abbreviated Injury Scale (AIS) 2+ and AIS 3+ severe head injuries with probability of 50 percent were caused by head impact velocity at about 33 and 49 km/h, respectively. Further, the predicted head linear acceleration (head injury criterion, HIC) value, resultant angular velocity, and resultant angular acceleration for 50 percent probability of AIS 2+ and AIS 3+ head injury risk were 116 g, 825, 40 rad/s, 11,368 rad/s² and 162 g, 1442, 55 rad/s, 18,775 rad/s², respectively, and the predicted value of 50 percent probability of skull fracture was 135 g.

Conclusions: The present study provides new insight into pedestrian head impact conditions in terms of velocity, angle, and impact location based on a number of real-world cases. Therefore, it may perform a critical analysis for current pedestrian head standard tests.

Keywords:

• pedestrian
• accident reconstruction
• dynamic response
• head injury

Acknowledgments

The authors thank the In-Depth Investigation of Vehicle Accidents in Changsha (IVAC) team and the Accident Research Unit (ARU) of the Medical University of Hannover for the valuable accident data. The authors also thank Chao Zhang, Director of Traffic Administration of Hunan Province; Xuelong Zhou, President of Institute of Police in Hunan Province; and Zhimin Liu, the Director of Traffic Police Section in Changsha. In addition, the authors are grateful for the financial support of the China Scholarship Council (CSC) and Foundation MAIF, France.

Supplementary materials are available for this article. Go to the publisher's online edition of Traffic Injury Prevention to view the supplemental file.