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Obesity rates are increasing among the general population. This study investigates the effect of obesity on ejection and injury risk in rollover crashes through analysis of field accident data contained in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) database. The study involved front outboard occupants of age 15+ years in 1994+ model year vehicle rollover crashes. Occupants were sorted into two BMI groups, normal (18.5 kg/m2 ≤ BMI < 25.0 kg/m2) and obese (BMI ≥30 kg/m2). Complete and partial ejection risks were first assessed by seating location relative to roll direction and belt use. The risk of serious-to-fatal injuries (MAIS 3+F) in non-ejected occupants were then evaluated. The overall risk for complete ejection was 2.10% ± 0.43% when near-sided and 2.65% ± 0.63% when far-sided, with a similar risk for both the normal and obese BMI groups.

Occupant ejection has been identified as a safety problem for decades, particularly in rollover crashes. While field accident studies have repeatedly demonstrated the effectiveness of seat belts in mitigating rollover ejection and injuries, the use of laminated glass in side window positions has been suggested as a means to mitigate occupant ejection. Limited data is available on the field performance of laminated glass in preventing ejection. This study utilized 1997-2015 NASS-CDS data to investigate the reliability of the glazing coding variables in the database and determine if any conclusions can be drawn regarding the effect of different side window glazing types on occupant ejection. An initial query was run for 1997-2016 model year vehicles involved in side impacts to evaluate glazing coding within NASS-CDS.

By their nature as chaotic, high-energy events, rollovers pose a high risk of injury to unrestrained occupants, in particular through exposure to projected perimeter contact and ejection. While seat belts have long been accepted as a highly effective means of retaining and restraining occupants in rollover crashes, it has been suggested that technologies such as laminated safety glazing or rollover-activated side curtain airbags (RSCAs) could alternatively provide effective occupant containment. In this study, a full-scale dolly rollover crash test was performed to assess the occupant containment capability of laminated side glazing and RSCAs in a high-severity rollover event. This allowed for the analysis of unrestrained occupant kinematics during interaction with laminated side glazing and RSCAs and evaluation of failure modes and limitations of laminated glazing and RSCAs as they relate to partial and complete ejection of unrestrained occupants.

Over the past decade, there has been an increase in awareness and concern about the occurrence and long-term effects of concussions. Traumatic brain injury (TBI)-related emergency department (ED) visits associated with motor vehicle collisions, including patients with a diagnosis of concussion or mild TBI (mTBI), have increased while deaths and hospital admissions related to TBI have decreased. The diagnostic criteria for concussion have evolved and broadened, and based on current assessments and diagnostic imaging techniques, there are often no objective findings, yet a diagnosis of concussion may still be rendered. Clinical assessment of concussion may be based only on patient-reported symptoms and history, making it difficult to objectively relate the reported increase in TBI-related ED visits due to motor vehicle collisions to specific collision parameters.

Physical evidence on the seat belt restraint system is one source of data used by investigators to determine whether or not an occupant was wearing their seat belt during a crash. Evidence of occupant loading on seat belts generated during crash events has been thoroughly researched and is well documented in the literature. However, there is a paucity of data regarding the physical evidence produced when fractured glass is introduced into the restraint system during occupant loading events. The objective of this study is to characterize the physical evidence generated by glass-to-seat belt interaction during low-level impact loading, and compare this evidence with the types of seat belt marks that can be generated inadvertently by accident scene bystanders, emergency responders, and crash investigators. The presence of glass particles in and around the vehicle at the end of a crash event may contribute to the inadvertent generation of physical evidence.

Low-speed collisions between tractor-semitrailers and passenger vehicles may result in large areas of visible damage to the passenger vehicle, but often produce limited damage to the tractor-semitrailer. Despite this, such accidents may lead to assertions of serious injury to the tractor driver and/or sleeper compartment occupant. Research regarding the impact environment and resulting injury potential of the occupants during these types of impacts is limited. This research investigated driver and sleeper compartment occupant responses to relatively low-speed and low-acceleration impact events. Five crash tests involving impact between a tractor-semitrailer and a passenger car were conducted. The test vehicles were a van semitrailer pulled by a tractor and three identical mid-sized sedans. The occupants of the tractor included a human driver and an un-instrumented Hybrid III 50th-percentile-male anthropomorphic test device (ATD).

Low-speed sideswipe collisions between tractor-semitrailers and passenger vehicles may result in large areas of visible damage to the passenger vehicle. However, due to the extended contact that occurs during these impacts, it is typical in these incidents for the crash pulse duration to be long and the vehicle accelerations to be correspondingly low. Research regarding the impact environment and resulting injury potential of the occupants during these types of impacts is limited. Five full-scale crash tests utilizing a tractor-semitrailer and a passenger car were conducted to explore the occupant responses during these types of collisions. The test vehicles included a van semitrailer pulled by a tractor and three identical mid-sized sedans. The occupants of the sedans included an instrumented Hybrid III 5th -percentile-male anthropomorphic test device (ATD) in the driver's seat and an un-instrumented Hybrid III 5th -percentile-female ATD in the left rear seat.

Rollover events involving multiple revolutions are dynamic, high-energy, chaotic events that may result in occupant injury. As such, there is ongoing discussion regarding methods that may reduce injury potential during rollovers. It has been suggested that increasing a vehicle's roof strength will mitigate injury potential. However, numerous experimental studies and published field accident data analyses have failed to show a causal relationship between roof deformation and occupant injury. The current study examines occupant kinematics and injury mechanisms during dolly rollover testing of a vehicle with a high roof strength-to-weight ratio (SWR = 4.8). String potentiometers and high-speed video cameras were used to capture and quantify the dynamic roof motion throughout the rollover. Instrumented Anthropomorphic Test Devices (ATDs) in the front occupant positions allowed for the assessment of occupant kinematics, loading, and injury mechanics during the rollover event.

A simple two-dimensional particle model was previously developed to calculate occupant ejection trajectories in rollover crashes. Model parameters were optimized using data from a dolly rollover test of a 1998 Ford Expedition in which five unbelted anthropomorphic test devices (ATDs) were completely ejected. In the present study, the model was further validated against a dolly rollover test of a 2004 Volvo XC90 in which three unbelted ATDs were completely ejected. The findings from the experimental testing were then compared to two real world rollover crashes with occupant ejections that were captured on video. The crashes were reconstructed by analyzing the video footage and aerial images of the crash sites. In both cases, the model was able to accurately match the observed trajectories of the ejected occupants, and the optimized model parameters were similar to the values obtained from the dolly rollover testing.

Field accident data have demonstrated that occupant ejection during vehicle rollover is associated with a high risk of serious and fatal injury. Although it has been demonstrated that seat belt use is highly effective in preventing occupant ejections, it has been argued that occupant containment during rollover can be accomplished with the use of laminated side glazing. This study was conducted to evaluate the retention characteristics of production laminated side windows. The current vehicle fleet was surveyed for vehicles equipped with production laminated side glass. The survey examined relevant window system parameters including glass retention system, glass configuration, and window geometry. A representative subset of five front door systems from several manufacturers was chosen for further evaluation. In addition, one legacy rear door system with laminated glass was included for comparison.

Several studies have sought to investigate the biomechanics associated with “whiplash syndrome” by evaluating head kinematics in simulated low-speed rear-end collisions. However, the present study is the first to comprehensively measure head accelerations in six degrees of freedom for the purpose of estimating upper neck loads. In the first phase of the study, nine volunteers were instrumented with a sensor package to measure three-dimensional linear accelerations and angular velocities of the head during rear-end impacts while riding an amusement park bumper car. In the second phase, thirty volunteers were instrumented with the same sensors during selected vigorous activities, including hopping and skipping rope. The linear and rotational head accelerations as well as the calculated upper neck forces and moments for the two groups are presented and compared.

Lateral head motions, torso motions, lateral neck bending angles, and electromyographic (EMG) activity patterns of five human volunteer passengers are compared to lateral motions of a Hybrid III ATD during right-left and left-right fishhook steering maneuvers leading to vehicular tip-up. While the ATD maintained relatively fixed lateral neck angles, live subjects leaned their heads slightly inward and actively utilized their neck musculature to stiffen their necks against the lateral inertial loads. Except for differences in neck lateral bending, the Hybrid III ATD reasonably reflects occupant kinematics during the pre-trip phase of on-road rollovers.