Identifying heterogeneous factors for driver injury severity variations in snow-related rural single-vehicle crashes.

Snowy weather is consistently considered as a hazardous factor due to its potential leading to severe fatal crashes. A seven-year crash dataset including rural highway single vehicle crashes from 2010 to 2016 in Washington State is applied in the present study. Pseudo elasticity analysis is conducted to investigate significant impact factors and the temporal stability of model specifications is tested via a likelihood ratio test. The proposed model based on the seven-year dataset is able to capture the individual-specific heterogeneity across crash records for four significant factors, i.e., surface ice, male, and airbag combine deployment for minor injury, and male for serious injury and fatality. Their estimated parameters were found to be normal distribution instead of fixed value over the observations. Other significant impact factors with fixed effects are: inroad object, animal, overturn, surface wet, surface snow, unusual horizontal design, medium and high speed limits, driver age, impaired condition, no belt usage, vehicle type, airbag deployment. Especially, when compared to significant factors for crashes under other weather conditions, male indicator and impaired condition show significant higher effects in snow-related crashes. The results of temporal stability test show that the model specification is generally not temporally stable for driver injury severity model based on the years of crash data that were used, especially for longer period (more than 3-year dataset). Models that allow the explanatory variables to track temporal heterogeneity, are of great interest and can be explored in future research.

Factors affecting injury severity of single-vehicle rollover crashes in the United States.

Objective: This study investigated the confounding effects of factors on injury outcomes for all occupants in fatal single-vehicle crashes that involved a rollover event.Method: A generalized ordered logit model was used to investigate the role of roadway attributes, environmental factors, driver characteristics, and vehicle features in injury severity outcomes for occupants. Five years of single-vehicle rollover crash data for the United States were studied.Results: Results showed that the likelihood of serious and fatal injuries increases in rollover crashes with partial or complete ejection of the occupant, no seat belt use, speeding, higher posted speed limits, roadside and median rollovers, undulating terrain, blacktop road surface, and rural roads. We also found that evening, weekdays, previous driver crash, careless or inattentive driving, driver-passenger engagement, aggressive driving, and vehicle type affect injury severity. The deployment of airbags was associated with fewer serious and fatal injuries. Regional differences were found for injury severity outcomes in rollover crashes.Conclusions: The study provides valuable insight for reducing injury severity in single-vehicle crashes where a rollover occurs. Several proven countermeasures may prevent rollovers or reduce injury severity. These strategies include increasing seatbelt use, posting lower speed limits and installing speed enforcement cameras in high-risk areas, flattening roadside embankments, and promoting in-vehicle stability enhancement systems such as electronic stability control and rollover-activated side curtain airbags.

Compression-based injury variables from chestbands in far-side impact THOR sled tests.

Objective: This study seeks to determine compression (Cmax) and compression-related injury variables (velocity and viscous injury criterion: Vmax and VCmax) from chestband data in pure lateral and oblique far-side impact sled tests.Methods: The 3-point belt-restrained mid-sized male Test Device for Human Occupant Restraint (THOR) dummy was placed on a buck and subjected to side impacts with and without center-mounted airbags. The change in velocity was 8.3 m/s for all conditions. Two chestbands were routed around the outer circumference of the THOR at the levels of the third and sixth ribs. Maximum chest deflections were computed using strain gauge signals from the chestbands and their temporal contours. Three methods were used to determine deflection metrics. The first method paralleled methods used in previously published human cadaver studies; the second method used the actual anchor point location and actual alignment of the dummy's internal sensors; and the third method used the anchor location of the internal sensor but determined the sensor's locations on the contour confining to the aspect of the sensor. These 3 approaches are abbreviated as the SD, ID, and TD variables. The injury variables Cmax, Vmax, and VCmax were determined according to accepted procedures. Their peak magnitudes were extracted and an evaluation of their accuracy was made based on the SD method.Results: The average SD-based Cmax magnitudes for the upper and lower chest levels were 0.12 and 0.17 m/s, the Vmax magnitudes were 5.3 and 1.8 m/s, and the VCmax magnitudes were 0.24 and 0.15 m/s, respectively. Other data are given for all variables at the 2 levels of the thorax in the body of this paper. The ID-based peak variables were the lowest, and this observation was true regardless of the aspect, right or left side. In contrast, the SD method produced the greatest magnitudes of the variables. The VCmax variable had the greatest normalized difference among all 3 injury variables.Conclusions: Though the present study is limited in scope, the predetermined placement of the internal sensors in the THOR dummy underpredicted chest deflection-related injury variables, and the viscous criterion was the least reliable variable in these lateral and oblique far-side impact sled tests.

Vehicle configurations associated with anatomical-specific severe injuries resulting from traffic collisions.

Vehicles can be classified by configuration as either bonnet-type or cab-over type according to engine location. Compared to bonnet-type, the front compartment of cab-over type vehicles is considerably shorter; thus, it may be less likely to absorb the energy generated in a collision, and in turn be unable to prevent deformation of the occupant space and protect occupants from injury. This study was a cohort study involving 943 occupants of mini-vehicles who were injured in frontal collision accidents between 2001 and 2015 and transferred to Ohta Nishinouchi Hospital. The vehicle configuration was divided into bonnet-type and cab-over type (i.e., truck-type and wagon-type). The tested outcomes were anatomical-specific severe injury of the pelvis and extremities, the head and neck, the abdomen, and the chest. To estimate adjusted odds ratios (AOR) for associations between vehicle configuration and anatomical-specific severe injury, we fitted generalized estimating equations for each outcome. Compared with bonnet-type vehicles, a greater risk of serious pelvis and extremities injury was found for both truck (AOR: 2.21; 95% Confidence Interval [95% CI]: 1.22-4.00) and wagon-type vehicles (AOR: 3.43; 95%CI 1.60-7.39). For serious head and neck injury, truck-type vehicles were associated with greater risk (AOR: 2.04; 95% CI: 1.10-3.79) than bonnet-type vehicles, whereas wagon-type vehicles were not. Compared with the occupants of bonnet-type vehicles, cab-over type vehicle occupants were more likely to have serious pelvis and extremities injury during frontal collisions. Additionally, truck-type vehicle occupants were more likely to have serious head and neck injury than bonnet-type vehicle occupants. These findings are expected to promote safer behaviors for vehicle occupants and the automobile industry.

Assessment of the disaster medical response system through an investigation of a 43-vehicle mass collision on Jung-ang expressway.

PURPOSE: It was considered the challenges of the actual response and the potential for improvement, including the activities of the disaster response system, national emergency medical center, and the regional base hospital for the treatment of multiple traffic accident victims. The purpose of this study was to analyze the accident management system through real investigating the multiple collision over 10 vehicles with mass casualty events as a disaster situation. METHODS: This study was retrospective study to analyze the disaster event with multiple collision traffic accident on the expressway in Korea. We visited five medical centers for eight days since the accident occurred and interviewed the injured patients in this accident to examine the health status and medical records. After that, we visited the sixteen car-repair shops in four cities for real investigate about damaged vehicles. According to the arrangement of the accident situation for the accident vehicles through real-world investigation, we reproduced all parts of the accident scene, which were real-world investigated, by the accident situation sketch program. The collected data were summarized by Collision Deformation Classification (CDC) codes, and the medical records of the occupants were assessed using the Injury Severity Score (ISS). RESULTS: The cause of the accident was snow freezing of the road. The information about 72 injured patients on 31 damaged vehicles was collected by phone, visit, and actual accident investigation. Of the 72 patients who were examined, 4 were severely injured and 68 were mildly injured. The accident occurred in the order of Sedan 13 (41.9%), SUV 11 (35.5%), Truck 4 (12.9%), Van 2 (6.5%) and Bus 1 (3.2%). The median value of the age [lower quartile and upper quartile] was 43 [34.5-52] years old and the patients included 25 drivers, 11 passengers, 7 back seat passengers, and 29 bus passengers. CONCLUSION: The primary cause of this mass collision accident was road surface freezing, but the more serious secondary cause was a driver's inability to avoid the accident scene after the first collision. The severely injured occupants were occurred on the roads outside and inside the vehicle. In the event of a disaster, various teams from the police team, firefighting team, DMAT, EMS, road management team are gathered, and communication and command system between each team is important in order to identify and solve the disaster situation. To do this, it is important to develop manuals and prepare for training through repeated simulations.

Chest injuries of elderly postmortem human surrogates (PMHSs) under seat belt and airbag loading in frontal sled impacts: Comparison to matching THOR tests.

OBJECTIVE: The goal of the study was to develop experimental chest loading conditions that would cause up to Abbreviated Injury Scale (AIS) 2 chest injuries in elderly occupants in moderate-speed frontal crashes. The new set of experimental data was also intended to be used in the benchmark of existing thoracic injury criteria in lower-speed collision conditions. METHODS: Six male elderly (age >63) postmortem human subjects (PMHS) were exposed to a 35 km/h (nominal) frontal sled impact. The test fixture consisted of a rigid seat, rigid footrest, and cable seat back. Two restraint conditions (A and B) were compared. Occupants were restrained by a force-limited (2.5 kN [A] and 2 kN [B]) seat belt and a preinflated (16 kPa [A] and 11 kPa [B]; airbag). Condition B also incorporated increased seat friction. Matching sled tests were carried out with the THOR-M dummy. Infra-red telescoping rod for the assessment of chest compression (IRTRACC) readings were used to compute chest injury risk. PMHSs were exposed to a posttest injury assessment. Tests were carried out in 2 stages, using the outcome of the first one combined with a parametric study using the THUMS model to adjust the test conditions in the second. All procedures were approved by the relevant ethics board. RESULTS: Restraint condition A resulted in an unexpected high number of rib fractures (fx; 10, 14, 15 fx). Under condition B, the adjustment of the relative airbag/occupant position combined with a lower airbag pressure and lower seat belt load limit resulted in a reduced pelvic excursion (85 vs. 110 mm), increased torso pitch and a substantially lower number of rib fractures (1, 0, 4 fx) as intended. CONCLUSIONS: The predicted risk of rib fractures provided by the THOR dummy using the Cmax and PC Score injury criteria were lower than the actual injuries observed in the PMHS tests (especially in restraint condition A). However, the THOR dummy was capable of discriminating between the 2 restraint scenarios. Similar results were obtained in the parametric study with the THUMS model.

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.

Front Airbag Deployment Rates in Real-World Car Accidents in Japan and Implications for Activation of Accident Emergency Calling System.

Accident emergency calling systems (AECSs) are signaled by the deployment of airbags, which causes them to automatically emit information providing the location of the accident site to a public service answering party (PSAP). In some realworld accidents, airbags have failed to deploy. This study clarifies the factors that influence the nondeployment of front airbags in vehicle-vehicle collisions, investigating nondeployment of the driver-side front airbags in sedans and light passenger cars (LPCs) from Japanese accident data. The component rates of deployment for front airbags tend to be higher than those of nondeployment at higher values of pseudo-ΔV in vehicle-vehicle frontal impacts. For both sedans and LPCs, the transition zones between nondeployment and deployment of the front airbag occur at pseudo-ΔV values of 30-50 km/h (ΔV ≈ 21-35 km/h). For mutual impact locations where sedans and LPCs impact opponent vehicles at pseudo-ΔV ≥ 40 km/h (ΔV ≈ 28 km/h) in frontal impacts, the component rate of front airbag nondeployment is higher than that of deployment in right-to-right impacts. The results indicate that factors influencing front airbag nondeployment in vehicle-vehicle collisions are ΔV, impact offset configuration, and crossing angle. Considering front airbag nondeployment in real-world accidents, AECSs should have other functions, such as a manual button, to emit information in addition to automatic emission via airbag signaling.

Decomposition analysis of the effects of vehicle safety technologies on the motor vehicle collision-related mortality rate from 1994 to 2015.

OBJECTIVE: Though the mortality rate for motor vehicle collisions (MVCs) has been decreasing since the 1960s with the advent of the first federal seat belt laws in 1968, MVC remains a leading cause of death for individuals aged 1 to 44 years. The purpose of this study is to examine the effects of frontal (FABs) and side airbags (SABs) and electronic stability control (ESC) on the components of the MVC mortality rate. METHODS: The MVC mortality rate from 1994 to 2015 was separated into its components of exposure of vehicles, exposure of travel, collision density, injury incidence, and case fatality rate. Year was categorized on the availability of safety technology in vehicles: 1994-1997 (first-generation FABs mandated), 1998-2001 (sled-certified, second-generation FABs mandated), 2002-2006 (increasing prevalence of SABs and ESC), 2007-2011 (advanced airbags mandated), and 2012-2015 (ESC mandated, SAB in over 90% of vehicles, introduction of advanced safety systems). Relative contributions (RCs) of the components to changes in the MVC-related mortality rate were calculated as the absolute value of the component's beta coefficient divided by the sum of the absolute values of all components' beta coefficients. Negative binomial regression-estimated rate ratios (RRs) for the changes in the rate of each component by year category compared to the prior year category. RESULTS: Significant decreases in the MVC mortality rate were observed for 2007-2011 and 2012-2015. The decrease in 2007-2011 was due in most part to an 18% decrease in the injury incidence (RR = 0.82, P < .0001, RC = 63%), though there was a noted contribution by the decrease in vehicle miles traveled (RR = 0.95, P < .0001, RC = 15%). The continued decrease in mortality in 2012-2015 was due is most part to the 10% decreased case fatality rate (RR = 0.90, P < .0001, RC = 66%) because there was no significant change in the vehicle miles traveled and injury incidence. CONCLUSIONS: The results of this study highlight the effects of vehicle safety technologies on the MVC-related mortality rate and can help direct prevention efforts. Through the study period, there was no meaningful contribution to decreases in the MVC-related mortality rate due to components related to exposure (i.e., vehicles per population and the rate of vehicle miles traveled), suggesting that prevention efforts at decreasing exposure prevalence would have little effect on the MVC-related mortality rate. Instead, prevention efforts should continue to focus on event-phase methods to decrease injury occurrence and mitigate injury severity during the collision.

Patterns of Facial Fractures and Protective Device Use in Motor Vehicle Collisions From 2007 to 2012.

IMPORTANCE: Facial fractures after motor vehicle collisions are a significant source of facial trauma in patients seen at trauma centers. With recent changes in use of seat belts and advances in airbag technology, new patterns in the incidence of facial fractures after motor vehicle collisions have yet to be quantified. OBJECTIVES: To evaluate the incidence of facial fractures and assess the influence of protective device use in motor vehicle collisions in patients treated at trauma centers in the United States. DESIGN, SETTING, AND PARTICIPANTS: Using a data set from the National Trauma Data Bank, we retrospectively assessed facial fractures in motor vehicle collisions occurring from 2007 through 2012, reported by level I, II, III, and IV trauma centers. Data analysis was performed from March 13 to September 22, 2015. MAIN OUTCOMES AND MEASURES: We characterized the data set by subsite of facial injury using International Classification of Diseases, Ninth Revision codes including mandible, midface, and nasal fractures. We assessed the influence of variables such as age, sex, race/ethnicity, crash occupant (driver or passenger), use of protective device, and presence or suspicion of alcohol use. RESULTS: A total of 518 106 patients required assessment at a trauma center after a motor vehicle collision, with 56 422 (10.9%) experiencing at least 1 facial fracture. Nasal fracture was the most common facial fracture (5.6%), followed by midface (3.8%), other (3.2%), orbital (2.6%), mandible (2.2%), and panfacial fractures (0.8%). Of the subset sustaining at least 1 facial fracture, 5.8% had airbag protection only, 26.9% used a seat belt only, and 9.3% used both protective devices, while 57.6% used no protective device. Compared with no protective device, the use of an airbag alone significantly reduced the likelihood of facial fracture after a motor vehicle collision (odds ratio, 0.82; 95% CI, 0.79-0.86); use of a seat belt alone had a greater effect (odds ratio, 0.57; 95% CI, 0.56-0.58) and use of both devices provided the greatest odds reduction (odds ratio, 0.47; 95% CI, 0.45-0.48). Younger age, male sex, and alcohol use significantly increased the likelihood of facial fracture. CONCLUSIONS AND RELEVANCE: For patients who presented to US trauma centers after motor vehicle collisions between 2007 and 2012, airbags, seat belts, and the combination of the 2 devices incrementally reduced the likelihood of facial fractures. LEVEL OF EVIDENCE: 3.

A comparison of contributing effects on 2-vehicle alcohol-related crashes between impaired and nonimpaired operators.

OBJECTIVE: Driving under the influence of alcohol is a crime that places the lives of all motorists in danger. Though it is a largely preventable act, impaired driving has accounted for 31 to 38% of fatal crashes across the country over the last decade. When an impaired operator crashes his or her vehicle, there is often a second unit, of which the operator is not impaired, involved in the crash. METHODS: This research looks at approximately 14,000 2-unit crashes involving an impaired operator in the State of Ohio from 2008 through 2012. The research is focused on determining the effects of crash and operator characteristics in 2-unit alcohol-related crashes through the use of 2 mixed logit models. RESULTS: It is found that several factors have similar effects on the injury severities of both the impaired and nonimpaired operators, including head-on crashes, the use of seat belts, and the deployment of airbags. There are, however, several factors that affect the 2 operators differently. It is found that the impaired operator's injury severity is based on the type and, more important, the size of the vehicle he or she is driving, the roadway geometry, and the speed of the vehicle driven by the nonimpaired operator. The nonimpaired operator is equally affected by the speed of the impaired vehicle as much as his or her own speed, and the nonimpaired operator's injury severity is virtually independent of the type of vehicle being driven. CONCLUSIONS: Researchers may disseminate the results to community groups such as Mothers Against Drunk Driving and Safe Communities to increase awareness of the dangers of drunk driving in an effort to reduce the number of alcohol-related crashes.

Difference in dummy responses in matched side impact tests of vehicles with and without side airbags.

OBJECTIVE: Insurance Institute for Highway Safety (IIHS) high-hooded side impacts were analyzed for matched vehicle tests with and without side airbags. The comparison provides a measure of the effectiveness of side airbags in reducing biomechanical responses for near-side occupants struck by trucks, SUVs, and vans at 50 km/h. METHOD: The IIHS moving deformable barrier (MDB) uses a high-hooded barrier face. It weighs 1,500 kg and impacts the driver side perpendicular to the vehicle at 50 km/h. SID IIs dummies are placed in the driver and left second-row seats. They represent fifth percentile female occupants. IIHS tests were reviewed for matches with one test with a side airbag and another without it in 2003-2007 model year (MY) vehicles. Four side airbag systems were evaluated: (1) curtain and torso side airbags, (2) head and torso side airbag, (3) curtain side airbag, and (4) torso side airbag. There were 24 matched IIHS vehicle tests: 13 with and without a curtain and torso side airbags, 4 with and without a head and torso side airbag, 5 with and without a side curtain airbag, and 2 with and without a torso airbag. The head, chest, and pelvis responses were compared for each match and the average difference was determined across all matches for a type of side airbag. RESULTS: The average reduction in head injury criterion (HIC) was 68 ± 16% (P < .001) with curtain and torso side airbags compared to the HIC without side airbags. The average HIC was 296 with curtain and torso side airbags and 1,199 without them. The viscous response (VC) was reduced 54 ± 19% (P < .005) with curtain and torso side airbags. The combined acetabulum and ilium force (7 ± 15%) and pelvic acceleration (-2 ± 17%) were essentially similar in the matched tests. The head and torso side airbag reduced HIC by 42 ± 30% (P < .1) and VC by 32 ± 26% compared to vehicles without a side airbag. The average HIC was 397 with the side head and torso airbag compared to 729 without it. The curtain airbag and torso airbag only showed lower head responses but essentially no difference in the chest and pelvis responses. CONCLUSION: The curtain and torso side airbags effectively reduced biomechanical responses for the head and chest in 50 km/h side impacts with a high-hooded deformable barrier. The reductions in the IIHS tests are directionally the same as estimated fatality reductions in field crashes reported by NHTSA for side airbags.

Underutilization of occupant restraint systems in motor vehicle injury crashes: A quantitative analysis from Qatar.

INTRODUCTION: Restraint systems (seat belts and airbags) are important tools that improve vehicle occupant safety during motor vehicle crashes (MVCs). We aimed to identify the pattern and impact of the utilization of passenger restraint systems on the outcomes of MVC victims in Qatar. METHODS: A retrospective study was conducted for all admitted patients who sustained MVC-related injuries between March 2011 and March 2014 inclusive. RESULTS: Out of 2,730 road traffic injury cases, 1,830 (67%) sustained MVC-related injuries, of whom 88% were young males, 70% were expatriates, and 53% were drivers. The use of seat belts and airbags was documented in 26 and 2.5% of cases, respectively. Unrestrained passengers had greater injury severity scores, longer hospital stays, and higher rates of pneumonia and mortality compared to restrained passengers (P = .001 for all). There were 311 (17%) ejected cases. Seat belt use was significantly lower and the mortality rate was 3-fold higher in the ejected group compared to the nonejected group (P = .001). The overall mortality was 8.3%. On multivariate regression analysis, predictors of not using a seat belt were being a front seat passenger, driver, or Qatari national and young age. Unrestrained males had a 3-fold increase in mortality in comparison to unrestrained females. The risk of severe injury (relative risk [RR] = 1.82, 95% confidence interval [CI], 1.49-2.26, P = .001) and death (RR = 4.13, 95% CI, 2.31-7.38, P = .001) was significantly greater among unrestrained passengers. CONCLUSION: The nonuse of seat belts is associated with worse outcomes during MVCs in Qatar. Our study highlights the lower rate of seat belt compliance in young car occupants that results in more severe injuries, longer hospital stays, and higher mortality rates. Therefore, we recommend more effective seat belt awareness and education campaigns, the enforcement of current seat belt laws, their extension to all vehicle occupants, and the adoption of proven interventions that will assure sustained behavioral changes toward improvements in seat belt use in Qatar.

Finite element comparison of human and Hybrid III responses in a frontal impact.

The improvement of finite element (FE) Human Body Models (HBMs) has made them valuable tools for investigating restraint interactions compared to anthropomorphic test devices (ATDs). The objective of this study was to evaluate the effect of various combinations of safety restraint systems on the sensitivity of thoracic injury criteria using matched ATD and Human Body Model (HBM) simulations at two crash severities. A total of seven (7) variables were investigated: 3-point belt with two (2) load limits, frontal airbag, knee bolster airbag, a buckle pretensioner, and two (2) delta-v's - 40kph and 50kph. Twenty four (24) simulations were conducted for the Hybrid III ATD FE model and repeated with a validated HBM for 48 total simulations. Metrics tested in these conditions included sternum deflection, chest acceleration, chest excursion, Viscous Criteria (V*C) criteria, pelvis acceleration, pelvis excursion, and femur forces. Additionally, chest band deflection and rib strain distribution were measured in the HBM for additional restraint condition discrimination. The addition of a frontal airbag had the largest effect on the occupant chest metrics with an increase in chest compression and acceleration but a decrease in excursion. While the THUMS and Hybrid III occupants demonstrated the same trend in the chest compression measurements, there were conflicting results in the V*C, acceleration, and displacement metrics. Similarly, the knee bolster airbag had the largest effect on the pelvis with a decrease in acceleration and excursion. With a knee bolster airbag the simulated occupants gave conflicting results, the THUMS had a decrease in femur force and the ATD had an increase. Preferential use of dummies or HBM's is not debated; however, this study highlights the ability of HBM metrics to capture additional chest response metrics.

Safety of the Japanese K-car in a real-world low-severity frontal collision.

OBJECTIVE: Kei-cars (K-cars), which are a tiny 660 cc mini-car class 3.4 m long or less, 1.48 m wide or less, and 2.00 m high or less, have become popular in Japan. To evaluate the safety of K-car drivers in frontal collisions, we retrospectively compared the severity of injuries suffered by drivers between K-cars and standard vehicles involved in frontal collisions in which at least one injury occurred. MATERIALS AND METHODS: From in-depth data provided by the Institute for Traffic Accident Research and Data Analysis from 1993 to 2010, records for 1379 drivers aged 36.8 ± 15.6 years were collected for analysis. RESULTS: Of the 1379 drivers, 1115 subjects were in standard vehicles and 264 were in K-cars. The mean delta V of the struck vehicle was 28.6 ± 15.6 km/h. After classifying the subjects according to seat belt use and air bag deployment, the background of the drivers and delta V, the injury severity scores (ISSs) and Abbreviated Injury Scale (AIS) scores were compared for all body regions. Under similar conditions, no significant differences in severity of injuries of the drivers were found between K-cars and standard vehicles. CONCLUSIONS: Although we are generally concerned that drivers of small vehicles suffer more severe injuries, our results suggest that, for real-world accidents, K-cars provide similar safety for drivers involved in frontal collisions as standard vehicles in low delta V impact conditions.

Time to death analysis of road traffic accidents in relation to delta V, drunk driving, and restraint systems.

OBJECTIVE: The main goal of this research is to identify variables related to the expected time to death due to road traffic accidents (RTAs). Such research is expected to be useful in improving safety laws and regulations and developing new safety systems. The resulting information is crucial not only for reducing accident fatalities but for assessing related insurance policies. METHODS: In this article, we analyze factors that are potentially associated with variation in the expected survival time after a road traffic accident using Weibull regression. In particular, we consider the association with alcohol involvement, delta V, and restraint systems. RESULTS: Our empirical results, obtained based on the NASS-CDS, indicate that the expected survival time for non-alcohol-impaired drivers is 3.23 times longer at a delta V of 50 km/h than that for alcohol-impaired drivers under the same conditions. In addition, it was observed that, even when occupants were alcohol-impaired, if they were protected by both air bags and seat belts, their expected survival time after an RTA increased 2.59-fold compared to alcohol-impaired drivers who used only seat belts. CONCLUSION: Our findings may be useful in improving road traffic safety and insurance policies by offering insights into the factors that reduce fatalities.

Restraints and peripheral nerve injuries in adult victims of motor vehicle crashes.

The pattern of injuries in restrained victims of motor vehicle crashes (MVCs) remains an issue of debate. We investigated the association of peripheral nerve injuries with the use of protective devices (seat belt and air bag) during MVCs. We performed a retrospective cohort study of 384,539 adult MVC victims who were registered in the National Trauma Data Bank (NTDB) between 2009 and 2011. Regression techniques were used to investigate the association of restraint use with the risk of peripheral nerve injury in patients hospitalized after an MVC. Of the study patients, 271,099 were using restraints and 113,440 were not. Overall, there were a total of 3086 peripheral nerve injuries. Multivariable logistic regression analysis demonstrated an association of protective device use with decreased risk of peripheral nerve injury (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.82-0.96; absolute risk reduction, 10.68%). This corresponds to 16 patients who needed to be restrained to prevent one nerve injury. The location of the patient in the vehicle did not seem to affect the risk of peripheral nerve injury, with drivers demonstrating no association with nerve injuries (OR, 0.94; 95% CI, 0.87-1.02) in comparison with non-drivers. On the contrary, alcohol consumption was associated with increased incidence of peripheral nerve injuries (OR, 1.10; 95% CI, 1.01-1.20). In summary, restraint use was associated with decreased risk of peripheral nerve injury in MVC victims, after controlling for confounders.

Perinatal implications of motor vehicle accident trauma during pregnancy: identifying populations at risk.

OBJECTIVE: The purpose of this study was to examine the association between restraint use, race, and perinatal outcome after motor vehicle accidents (MVAs) during pregnancy. STUDY DESIGN: The Duke Trauma Registry and medical records were searched for information on pregnant women at >14 weeks' gestation who were involved in an MVA and who received care through the Emergency Department and the Obstetric Units. Between January 1994 and December 31, 2010, 126 women were identified. Variables that were collected included type of trauma, gestational age at presentation, and delivery outcomes. A prognostic study was performed that evaluated the associations between maternal demographics, details of the accident that included restraint use, and maternal treatment that was related to the accident in relationship to perinatal outcome. RESULTS: There was no difference in the mean age or median gravidity or parity by race among pregnant women who were cared for after an MVA. There was no difference in mean age or racial distribution between women who were restrained compared with women who were unrestrained; unrestrained women were more likely to be nulliparous. Unrestrained women were more likely to require nonobstetric surgery that was related to the trauma. The overall rate of placental abruption was 6%. There were 6 intrauterine fetal deaths, 3 each in the unrestrained (25%) and restrained groups (3.5%; P = .018). Airbags deployed in 17 accidents. Among the 7 women with placenta abruption, 4 women (57%) experienced air bag deployment. CONCLUSION: Lack of restraint use during pregnancy is associated with an increased risk of fetal death.

Do seat belts and air bags reduce mortality and injury severity after car accidents?

We studied National Trauma Data Bank data to determine the effectiveness of car safety devices in reducing mortality and injury severity in 184,992 patients between 1988 and 2004. Safety device variables were seat belt used plus air bag deployed; only seat belt used; only air bag deployed; and, as explicitly coded, no device used. Overall mortality was 4.17%. Compared with the no-device group, the seat-belt-plus-air-bag group had a 67% reduction in mortality (adjusted odds ratio [AOR], 0.33; 99% confidence interval [CI], 0.28-0.39), the seatbelt- only group had a 51% mortality reduction (AOR, 0.49; 99% CI, 0.45-0.52), and the air-bag-only group had a 32% mortality reduction (AOR, 0.68, 99% CI, 0.57-0.80). Injury Severity Scores showed a similar pattern.

Door velocity and occupant distance affect lateral thoracic injury mitigation with side airbag.

The relationship between thoracic injury risk and parameters of door velocity and occupant distance was delineated in blunt lateral impact with side airbag deployment. A sled impact model was exercised with the validated MADYMO fiftieth percentile facet occupant model and a generalized finite element torso side airbag. Impact velocity was incremented from 4.0 to 9.0m/s; occupant-airbag distance (at time of airbag activation) was incremented from 2.0 to 24.0 cm; simulations without airbag were also examined. Using compression, deflection rate, and the Viscous Criterion, airbag performance was characterized with respect to occupant injury risk at three points of interest: occupant distance of most protection, distance of greatest injury risk, and the newly defined critical distance. The occupant distance which demonstrated the most airbag protection, i.e., lowest injury risk, increased with increasing impact velocity. Greatest injury risk resulted when the occupant was nearest the airbag regardless of impact velocity. The critical distance was defined as the farthest distance at which airbag deployment exacerbated injury risk. This critical distance only varied considering chest compression, between 3 and 10 cm from the airbag, but did not vary when the Viscous Criterion was evaluated. At impact velocities less than or equal to 6m/s, the most protective occupant location was within 2 cm of the critical distance at which the airbag became harmful. Therefore, injury mitigation with torso airbag may be more difficult to achieve at lower ΔV.