Principal Investigator: Aditya Belwadi, PhD, Children’s Hospital of Philadelphia
Below is an executive summary of this project. Please note that this summary describes results and interpretation that may not be final. Final interpretation of results will be in the peer-reviewed literature.
Although rollover crashes account for only about 3 percent of crashes, they are the cause of more than 33 percent of all motor vehicle-related fatalities and have the highest fatality risk of all crash types in the United States. Very limited pediatric-specific data related to rollover crashes currently exists, despite the importance of evaluating injury causation, particularly with data from crashes involving the current fleet.
The objectives of this project were:
1) to examine available real world data regarding children in rollover crashes, calculate injury risk, determine injury patterns and causation, and identify areas of occupants’ contact with the vehicle in order to guide development of injury mitigation technology
2) to evaluate the feasibility of using computer models to aid in pediatric rollover research.
To provide a contemporary analysis of rollover crashes involving children, researchers queried the National Automotive Sampling System’s Crashworthiness Data System (NASS-CDS) and the Crash Injury Research and Engineering Network (CIREN) from case years 1998 through 2012. Rollover crashes for passenger vehicles of model year 1998 or newer with at least one restrained occupant (excluding drivers) between 0 and 19 years of age were included. Using the NASS-CDS dataset, univariate and multi-variate logistic regression models of injuries with an Abbreviated Injury Scale maximum score (MAIS) of 2+ or 3+ were used to examine the relationship between the key factors of the crash and the injury outcomes for the vehicle occupants. From the CIREN dataset, vehicle components that served as contact points (such as the roof or a vehicle door) and details of the occupant’s injuries were used to develop contact maps.
The NASS-CDS study cohort consisted of 1,033 occupants weighted to represent 285,703 occupants. Risk analysis indicated that children restrained in forward-facing child restraint systems or booster seats were less likely to sustain an MAIS 2+ injury than occupants restrained with a lap and shoulder belt in a rollover crash. This supports the protective effect of supplemental child restraint systems for younger occupants. The abdomen was the most commonly injured body region at the MAIS 2+ level, while the head was most common at the MAIS 3+ level, followed by the thorax and spine. Of the 20 CIREN cases that met the inclusion criteria, 15 had one or more injuries attributed to contact with some part of the vehicle structure. The CIREN analyses revealed that the head was the most common seriously injured body region, primarily due to contact with the roof side rail and/or vehicle interior. This finding was true for both adolescents and younger child passengers in outboard seating positions.
The final phase of this project involved reconstructing an exemplar CIREN case using computational modeling techniques. The objective of the modeling effort was to understand the effect of a rollover crash on restrained pediatric occupant kinematics. The analysis was performed in two stages:
1) vehicle-to-vehicle dynamics and deformations were reconstructed
2) simulation of the occupant kinematics and associated impact with the vehicle interior was conducted.
This line of research can ultimately provide vehicle and restraint system manufacturers with data needed to develop rollover injury-mitigation systems specifically for children.
Project Team Members
Kristy Arbogast, PhD, Children’s Hospital of Philadelphia; Caitlin Locey, BS, Children’s Hospital of Philadelphia; Matthew R. Maltese, PhD, Children’s Hospital of Philadelphia
Jessica Harrington, University of Delaware; Christine Evangelista, Elizabethtown College; Todd Hullfish, Drexel University
Mark Neal and Steve Cassatta, General Motors Holdings LLC; Doug Longhitano, American Honda Motor Co., Inc.; Uwe Meissner, Technical Advisor; Steve Ridella, National Highway Traffic Safety Administration; Schuyler St. Lawrence, Toyota Motor North America Inc.