Child Restraint System Misuse in the Field and in Full-Vehicle Crash Tests (Multiple Year Project)

Principal Investigators: Matt Maltese, MS, Children's Hospital of Philadelphia; Mark Zonfrillo, MD, MSCE, Children's Hospital of Philadelphia

Below is an executive summary of this line of research. Please note that each summary describes results and interpretation that may not be final. Final interpretation of results will be in the peer-reviewed literature.

Motor vehicle crashes continue to be the leading cause of death for children in the U.S., Canada, and Europe, and child restraint systems (CRS) can significantly reduce the risk of injury. Studies show, however, that CRS misuse can lead to less than optimal injury prevention when crashes occur. This improper CRS use includes not using the appropriate CRS for the child’s age, incorrectly attaching the CRS to the vehicle, and not harnessing the child in the CRS correctly.


The second phase of the study involved a series of full-scale frontal vehicle crash tests with a CRS, conducted and funded by Transport Canada. Focusing on rear-facing CRS, three broad categories of misuse were considered:

1) improper restraint selection or placement in the vehicle

2) incorrect or loose CRS-to-vehicle attachment

3) incorrect or loose restraint of the child in the CRS

Testing was conducted in the second row seat of passenger vehicles undergoing full frontal rigid barrier crash tests at approximately 25 and 30 mph. Two identical child restraints with instrumented CRABI 12 month or Q3 3-year-old crash test dummies were installed in each of the rear outboard positions of the test vehicles: one child restraint was “correctly installed” as per manufacturer instructions behind the driver seat; a second, identical child restraint was “incorrectly installed” behind the right front passenger seat to characterize one or more of the common ‘real-world’ misuse conditions. The resulting video images of the crash testing demonstrated a variety of potential injury scenarios.

By better understanding the current prevalence and types of misuse, and how misuse correlates to injury potential, both the crash and real-world data examined in this study have practical implications for the field. This information can inform and improve educational campaigns to consumers and provide a foundation for CRS and vehicle modifications that will continue to improve child safety in motor vehicles.



To understand the real world restraint practices of the CRS consumer, in phase 1 of this study we examined 10,000 CRS inspection forms from the Pennsylvania American Academy of Pediatrics (PA-AAP) Traffic Injury Prevention Project (TIPP) from 2007-2010. Data collected included descriptive variables of the CRS consumer and child including child anthropometry; vehicle and CRS variables including year, make and model; CRS condition variables, including damage assessment and condition of labeling, and misuse variables specific to the common CRS types (rear facing (RF) Infant, RF Convertible CRS, forward facing (FF) CRS, Booster) and restraint fit information for children in belt restraints. Three broad categories of misuse were considered:

1) improper restraint selection or placement in the vehicle

2) incorrect or loose CRS-to-vehicle attachment

3) incorrect or loose restraint of the child in the CRS

The results revealed important characteristics of the CRS consumer. We noted that children in rear-facing CRS were seated in the right front passenger seating position with an active air bag (3% of rear-facing CRS misuses) relatively infrequently. We also found that the LATCH attachment method was used in slightly more than half (51%) of all rear-facing CRS misuse conditions. One of the most common misuses in forward-facing CRS was loose attachment between the CRS and vehicle. Of note, the frequency of this type of misuse in LATCH cases (11%) was less than half than that in belt cases (26%). This suggests LATCH allows a greater percentage of parents to achieve a tighter fit on the CRS in the vehicle. To a lesser extent, this same effect was observed in rear-facing CRS, with belt or LATCH use roughly evenly split in the sample — with 13% of LATCH CRS found to be loose vs. 18% of belted CRS found to be loose.

We found that different types of misuses often occur together, suggesting that parents and caregivers are often generally misusing CRS rather than having difficulty mastering a single aspect of CRS installation. Incorrect tether use was often associated with other misuses of CRS-to-vehicle attachment, such as belt routing, improper LATCH use, and general looseness of the restraint. Incorrect choice of the harness slot was frequently seen with other harness-related misuses, such as improper harness retainer (chest) clip position and loose or misthreaded harness. Efforts to improve ease of use or clarity of instructions, combined with effective public safety messaging emphasizing the importance of proper CRS use, is warranted.


Kristy Arbogast, PhD, Children’s Hospital of Philadelphia; Suzanne Tylko, MSME, Transport Canada


Elizabeth Hedges, Cornell University (Year 2); Melanie Ward, University of Michigan (Year 1)

IAB Mentors

Richard Bandstra, Volkswagen Group of America Inc. (Year 1); Eric Dahle, Evenflo Company Inc. (Years 1 & 2); Doug Longhitano, Honda R&D Americas Inc. (Year 1); Uwe Meissner, Technical Advisor (Years 1 & 2); Keith Nagelski, Britax Child Safety Inc. (Year 1); Sara Seifert, Minnesota Health Solutions (Year 2); Ken Wittenauer, Britax Child Safety, Inc. (Year 2)