Serious head and neck injury as a predictor of occupant position in fatal rollover crashes

Investigating factors influencing rollover crash risk on mountainous interstates

INTRODUCTION

The risk of rollover crashes on mountainous roads is a major concern for transportation authorities due to adverse weather conditions and complex topography. Such crashes incur hazardous consequences on road users' lives. Therefore, it is crucial to identify the contributing factors that give rise to these severe crashes in order to identify preventive measures. Furthermore, exploring the potential sources of heterogeneity of rollover crash contributing factors is equally important.

METHOD

By having a dataset of single-vehicle crashes that occurred on mountainous curved sections in Wyoming, we applied a random parameters, otherwise known as mixed, logit model to identify the factors contributing to the increased risk of rollovers. Vehicle, driver, roadway, environmental, and crash attributes variables were considered as potential predictors in the model. Then, random parameters were identified to uncover the unobserved effects.

RESULTS

Weather, road surface conditions, and speeding were found to have a significant impact on rollover crash risk. These factors were also found to exhibit unobserved heterogeneity effects, which could be attributed to the drivers' responses and conditions. Furthermore, it was found that the propensity of rollovers was higher for sports utility vehicles (SUVs) and pick-up trucks among other vehicle types.

CONCLUSIONS

The results indicated that investigating the impact of these factors on the risk of rollovers while taking into account unobserved heterogeneity effects is an essential step for implementing countermeasures to reduce the frequency and severity of rollover crashes. Practical applications: This study uncovered insights into the factors that lead vehicles to overturn. This aids in suggesting appropriate safety countermeasures that mitigate the occurrences of rollover crashes to transportation agencies.

Relationship between head and neck injuries and helmet use in fatal motorcycle and moped crashes in Denmark

Motorcycle- and moped crashes are prevalent in motorised societies and carry a significant risk of serious injury. Whereas helmet use has reduced the frequency and severity of head injuries, the association between helmet use and neck injury risk is less clear. In the present retrospective study, we examined the relationship between helmet use and various types of head and neck injuries resulting from fatal motorcycle and moped crashes during a 20-year period. Eighty-three cases were included of whom 56 were analysed in detail based on their confirmed use/non-use of helmet. Intracranial haemorrhage was the most common finding, followed by CNS disruption and skull fracture. There was a significantly lower prevalence of skull vault fractures and epidural haemorrhage in the helmeted cases. Injuries to the brainstem and cervical spine fracture/dislocation were more common in the helmeted cases, although this was likely a function of higher speeds among motorcycle riders rather than an effect of helmet use per se. Further investigation of these findings require additional detailed information regarding the nature and severity of the crash, as well as helmet use and type, in order to assess non-confounded associations with the anatomical distribution, type and severity of observed head and neck injuries.

Rollover injury in vehicles with high-strength-to-weight ratio (SWR) roofs, curtain and side airbags, and other safety improvements

PURPOSE

This study investigated trends in severe injury and ejection in rollover crashes involving lap-shoulder-belted drivers and right-front passengers. It was conducted because of changes in 2009 to consumer information programs and regulations related to rollover protection. The data are presented by model year (MY) of the vehicle in groups from 1995 to 2016. NASS-CDS cases with 2010-2016 MY vehicles were also evaluated to determine the crash circumstances and causes for severe injury of belted occupants in vehicles with a high strength-to-weight (SWR) roof, curtain, and side airbags and other safety improvements.

METHODS

1997-2015 NASS-CDS data were evaluated for severe injury and ejection of lap-shoulder-belted front outboard occupants in light vehicles. Crashes were grouped by front, side, rear, and rollover. The injury and ejection data were grouped by vehicle MY: 1995-1999, 2000-2004, 2005-2009, and 2010-2016. Only drivers and right-front passengers were included if they were lap-shoulder belted and 15+ years old. Severely injured occupants were defined as those with Maximum Abbreviated Injury Scale (MAIS) 4-6 or fatality (MAIS 4 + F). National estimates were made with weighted data using the ratio weight in NASS-CDS. All NASS-CDS electronic cases were evaluated for belted occupants with MAIS 4 + F injury in rollovers involving 2010-2016 MY vehicles. The crash circumstances and injuries were studied. These vehicles had high-SWR roofs to meet Insurance Institute for Highway Safety (IIHS) ratings and FMVSS 216.

RESULTS

The 1997-2015 NASS-CDS included 2,083,776 belted front occupants in rollover crashes with 24,466 (1.17%) MAIS 4 + F injuries. The frequency of rollover crashes has decreased with modern vehicles (P < .0001). The 1995-1999 MY vehicles involved in a rollover accounted for 7.03% of all crashes (756,228/10,760,000). The corresponding proportion was 3.57% with 2010-2016 MY vehicles (81,406 vs. 2,282,062). The risk for MAIS 4 + F was 1.325 ± 0.347% in rollover crashes with 1995-1999 MY vehicles. It was 27.2% lower in 2010-2016 MY vehicles at 0.964 ± 0.331% (P < .001). There were 42,567 (2.002%) ejections of belted occupants in rollover crashes, irrespective of injury outcome. The risk for ejection was 3.042 ± 1.44% in rollover crashes with 1995-1999 MY vehicles. It was 43.6% lower in 2004-2009 MY vehicle at 1.715 ± 0.660% (P < .001) and 83.4% lower in 2010-2016 MY vehicle at 0.505 ± 0.336% (P < .001). There were 17 rollovers with MAIS 4 + F in 2010-2016 MY vehicles in NASS-CDS. Their roof strength was SWR =4.15 ± 1.05 based on 15 vehicles. Many of the collisions involved front or side impacts and then a rollover. Four cases involved 16- to 30-year-old drivers in extremely high-speed loss-of-control crashes resulting in >10-cm vertical roof deformation or substantial roof deformation based on photos. The roof strength (SWR) of 4.20 ± 1.0 was not sufficient to prevent roof deformation in these crashes.

CONCLUSIONS

This study found a reduction in severe injury and ejection risk with modern vehicles. It indicates that vehicle safety has improved in response to IIHS and NHTSA efforts to expand the array of safety requirements and increase performance so that newer models are safer than earlier ones. There has been an incremental improvement in safety due to these advances.

Integrating engineering principles into the medico-legal investigation of a rare fatal rollover car accident involving complex dynamics

Rollover car accidents can be the result of forceful steering or hitting an obstacle that acts like a ramp. Mortality from this type of car accident is particularly high, especially when occupants are thrown out of the vehicle. We report a case of a 67-year-old man who died after a rollover accident that occurred when he was driving a car equipped with a glass moonroof. He was found inside his car with his safety belt correctly fastened and the roof shattered. At autopsy, a wide avulsion injury of the head was observed, which was associated with an atlanto-axial dislocation and full-thickness fracture of the cervical body and posterior facet joints of the seventh cervical vertebra. The data collected at the scene of the accident were integrated with the autopsy results to yield a forensic engineering reconstruction. This reconstruction elucidated the dynamics of the event and correctly ascribed the lesions observed at autopsy to the phases of the rollover. Afterward, an analysis of the scientific literature concerning rollover crash tests was conducted to understand why the driver sustained fatal injuries even though his seatbelt was properly fastened.

Investigating driver injury severity patterns in rollover crashes using support vector machine models

Rollover crash is one of the major types of traffic crashes that induce fatal injuries. It is important to investigate the factors that affect rollover crashes and their influence on driver injury severity outcomes. This study employs support vector machine (SVM) models to investigate driver injury severity patterns in rollover crashes based on two-year crash data gathered in New Mexico. The impacts of various explanatory variables are examined in terms of crash and environmental information, vehicle features, and driver demographics and behavior characteristics. A classification and regression tree (CART) model is utilized to identify significant variables and SVM models with polynomial and Gaussian radius basis function (RBF) kernels are used for model performance evaluation. It is shown that the SVM models produce reasonable prediction performance and the polynomial kernel outperforms the Gaussian RBF kernel. Variable impact analysis reveals that factors including comfortable driving environment conditions, driver alcohol or drug involvement, seatbelt use, number of travel lanes, driver demographic features, maximum vehicle damages in crashes, crash time, and crash location are significantly associated with driver incapacitating injuries and fatalities. These findings provide insights for better understanding rollover crash causes and the impacts of various explanatory factors on driver injury severity patterns.

Forensic epidemiology: a method for investigating and quantifying specific causation

The field of forensic epidemiology was initially introduced as a systematic approach to the investigation of acts of bioterrorism. In recent years, however, the applications of forensic epidemiology have expanded greatly, covering a wide range of medicolegal issues routinely encountered in both criminal and civil court settings. Forensic epidemiology provides a method of evaluating causation in groups and individuals based in the application of the Hill Criteria, with conclusions given in terms of relative or comparative risk, or as a Probability of Causation. The purpose of this paper is to give a brief overview of the methods and applications of forensic epidemiology.