An enhanced method for evaluating the effectiveness of protective devices for road safety application.

This paper presents an enhanced probabilistic approach to estimate the real-world safety performance of new device concepts for road safety applications from the perspective of Powered Two-Wheeler (PTW) riders who suffer multiple injuries in different body regions. The proposed method estimates the overall effectiveness of safety devices for PTW riders by correlating computer simulations with various levels of actual injuries collected worldwide from accident databases. The study further develops the methodology initially presented by Johnny Korner in 1989 by introducing a new indicator, Global Potential Damage (GPD), that overcomes the limitations of the original method, encompassing six biomechanical injury indices estimated in five body regions. A Weibull regression model was fit to the field data using the Maximum Likelihood Method with boundaries at the 90% confidence level for the construction of novel injury risk curves for PTW riders. The modified methodology was applied for the holistic evaluation of the effectiveness of a new safety system, the Belted Safety Jacket (BSJ), in head-on collisions across multiple injury indices, body regions, vehicle types, and speed pairs without sub-optimizing it at specific crash severities. A virtual multi-body environment was employed to reproduce a selected set of crashes. The BSJ is a device concept comprising a vest with safety belts to restrict the rider's movements relative to the PTW during crashes. The BSJ exhibited 59% effectiveness, with an undoubted benefit to the head, neck, chest, and lower extremities. The results show that the proposed methodology enables an overall assessment of the injuries, thus improving the protection of PTW users. The novel indicator supports a robust evaluation of safety systems, specifically relevant in the context of PTW accidents.

Unlatching school bus seat belt buckles: Considerations for young passengers.

Automobile seat belts reduce the risk of injuries and fatalities resulting from a crash. As seat belts become more prevalent on large school buses, characterizing the capabilities of children to operate the unlatching mechanism of a seat belt is crucial to ensure the post-crash safety of young passengers. This study evaluated the strength capabilities of children and their abilities to unlatch a school bus seat belt when a school bus is in both the upright and rolled-over orientations. Push force exertions on a seat belt buckle push button were measured and compared to the seat belt assembly release force requirements specified in Federal Motor Vehicle Safety Standard (FMVSS) No. 209. Results of the study suggested that children do not have the strength to exert the maximum force of 133 N to release a seat belt assembly as specified in FMVSS No. 209; however, most children could unlatch a typical school bus seat belt assembly in the upright and rolled-over orientations.

Prediction of rear-seat belt use: Application of extended theory of planned behavior.

OBJECTIVES: Rear-seat belts have been shown to significantly reduce the severity of road vehicle collisions and fatalities. However, their use by rear-seat passengers is significantly less than that by front-seat passengers. Thus, the psychological factors underlying individuals' decision to wear a seat belt in the rear seat require further investigation. METHODS: An extended theory of planned behavior (eTPB) was used to examine individuals' behavior of wearing a rear-seat belt. An online survey was conducted and a total of 515 valid questionnaires were collected in China. RESULTS: While attitude, descriptive norms, and law enforcement all have a significant effect on individuals' intention to wear a seat belt in the rear, subjective norms and perceived behavioral control do not. Individuals' attitudes toward wearing a seat belt in the rear seat are significantly influenced by law enforcement and behavioral intention, but not by perceived behavioral control. The mediation effect analysis reveals that law enforcement has the greatest overall effect on behavior, followed by attitude and descriptive norms. CONCLUSIONS: The results of this paper contribute to more effective recommendations to improve the use of rear seat belts and to safeguard rear seat passengers.

Assessing injury risks of reclined occupants in a frontal crash preceded by braking with varied seatbelt designs using the SAFER Human Body Model.

OBJECTIVE: This study investigated the effects of different seatbelt geometries and load-limiting levels on the kinematics and injury risks of a reclined occupant during a whole-sequence frontal crash scenario, using simulations with the Active SAFER Human Body Model (Active SHBM). METHODS: The Active SHBM was positioned in a reclined position (50°) on a semi-rigid seat model. A whole-sequence frontal crash scenario, an 11 m/s2 Automated Emergency Braking (AEB) phase followed by a frontal crash at 50 km/h, was simulated. The seatbelt geometry was varied using either a B-pillar-integrated (BPI) or Belt-in-seat (BIS) design. The shoulder belt load-limiting level of the BPI seatbelt was also varied to achieve either similar shoulder belt forces (BPI_Lower_LL) or comparable upper body displacements (BPI_Higher_LL) to the BIS seatbelt. Kinematics of different body regions and seatbelt forces were compared. The risks of sustaining a mild traumatic brain injury (mTBI), two or more fractured ribs (NFR2+), and lumbar spine vertebral fractures were also compared. RESULTS: During the pre-crash phase, head, first thoracic vertebra, and first lumbar vertebra displacements were greater with the BPI seatbelt than with the BIS, mainly due to the lack of initial contact between the torso and the seatbelt. Pelvis pre-crash displacements, however, remained consistent across seatbelt types. In the in-crash phase, variations in shoulder belt forces were directly influenced by the different load-limiting levels of the shoulder belt. The mTBI (around 20%) and NFR2+ (around 70-100%) risks were amplified with BPI seatbelts, especially at higher load-limiting force. However, the BPI design demonstrated reduced lumbar spine fracture risks (from 30% to 1%). CONCLUSIONS: The BIS seatbelt appears promising, as seen with the reduced mTBI and NFR2+ risks, for ensuring the protection of reclined occupants in frontal crashes. However, additional solutions, such as lap belt load limiting, should be considered to reduce lumbar spine loading.

The influence of seated postures and anthropometry on lap belt fit in vehicle occupants: A 3D computed tomography study.

OBJECTIVE: In vehicle frontal collisions, it is crucial that the lap belt is designed to engage with the anterior superior iliac spine (ASIS) of occupants for a reliable restraint. This study aims to understand the influence of different seated postures on the geometrical relationship of the seat belt and the pelvis for various occupants using 3D upright and supine computed tomography (CT) systems. METHODS: The 3D shapes of bones and soft tissues around the pelvis were acquired through a CT scan for 30 participants. They were seated in a rigid seat equipped with a lap belt simulating the front seat of a small car, and wore a lap belt in three seated postures: upright, slouched and reclined. Parameters related to the likelihood of submarining occurrences, such as belt-ASIS overlap (an index for assessing the potential engagement of the lap belt with the ASIS) and the belt-pelvis angle (the difference between the belt angle and the normal direction of the anterior edge of the ilium) were compared. RESULTS: It was observed that the pelvis angle tilted rearward as the hip point was positioned forward and seatback angle increased. This can be seen in the slouched and reclined posture. The belt-pelvis angle was comparable between the slouched and the reclined postures, and was closer to zero (indicating that the lap belt path is closer to perpendicular to the anterior edge of the ilium) compared to the upright posture. In contrast, the belt-ASIS overlap increased with an increasing flesh margin of the ASIS and shallower belt angle. This suggests that the belt-pelvis angle is influenced by the seated posture whereas the belt-ASIS overlap is dependent more on an individual's anthropometry. The plot of belt-pelvis angle and belt-ASIS overlap exhibited significant variability among participants. CONCLUSIONS: The belt-pelvis angle and the belt-ASIS overlap of individuals will provide valuable information for understanding the current belt-fit location and predicting submarining occurrences for individuals in various postures when designing restraint systems.

Investigating the severity of single-vehicle truck crashes under different crash types using mixed logit models.

INTRODUCTION: Almost 90% of fatal road crashes occur in developing countries. Among these countries, Iran has a noticeable fatal crash rate of 21.47 deaths per 100,000 persons. Improving the safety of trucks is of particular importance in Iran where road freight is used to transport almost 90% of the commodities. Researchers have suggested dichotomizing crashes into single- and multi-vehicle categories and found that when this is performed vast differences can be identified between the mechanisms behind these categories of crashes, particularly when investigating truck crashes. METHOD: This study investigated single-vehicle truck crashes in Khorasan Razavi province in Iran from 2013 to 2021. Likelihood ratio tests were employed to show that separate models are statistically valid for different crash types. Subsequently, three mixed logit crash-type models were developed to investigate 5,703 single-vehicle truck crashes. RESULTS: Four significant variables were exclusive to collisions with an object (brake failure, ABS, primary roads, and rainy or snowy weather), five significant variables were associated with run-off-road crashes (driving a loaded truck, speed limit (>60 km/h), paved shoulders, driving uphill, and inability to control the truck), and three significant variables were associated with overturn crashes (overloaded truck, curved roads, and changing direction suddenly). In all crash types, both fastening the seatbelt and speeding were found to be significant factors. CONCLUSION: The research highlights the need to analyze single-vehicle truck crashes using distinct crash type models and highlights the unique contributing factors of three common single-vehicle crash types. PRACTICAL APPLICATIONS: The study presents recommendations for policy to address key crash risks for trucks in Iran, including education and training to improve driver experience, compliance with seat belt usage, enforcement of speeding, and vehicle technologies to monitor drivers.

Risk Factors for Blunt Cerebrovascular Injury in a Cohort of Pediatric Patients With Cervical Seat Belt Sign.

BACKGROUND: Blunt cerebrovascular injury (BVCI), injury to the carotid or vertebral arteries, may result from forces involving seatbelts. Although previous studies have not found a seat belt sign to be a significant predictor for BCVI, it is still used to screen patients for BCVI. OBJECTIVE: This study aims to determine risk factors for BCVI within a cohort of patients with seat belt signs. METHODS: We conducted a retrospective cohort study using our institutional trauma registry and included patients younger than 18 years with blunt trauma who both had a computed tomography angiography (CTA) of the neck performed and had evidence of a seat belt sign per the medical record. We reported frequencies, proportions, and measures of central tendency and conducted univariate analysis to evaluate factors associated with BCVI. We estimated the magnitude of the effect of each variable associated with the study outcome by conducting logistic regression and reporting odds ratios and 95% confidence intervals. RESULTS: Among all study patients, BCVI injuries were associated with Injury Severity Score higher than 15 ( P = 0.04), cervical spinal fractures ( P = 0.007), or basilar skull fractures ( P = 0.01). We observed higher proportions of children with BCVI when other motorized and other blunt mechanisms were reported as the mechanisms of injury ( P = 0.002) versus motor vehicle collision. CONCLUSIONS: Significant risk factors for BCVI in the presence of seat belt sign are: Injury severity score greater than 15, cervical spinal fracture, basilar skull fracture, and the other motorized mechanism of injury, similar to those in all children at risk of BCVI.

Distinctive Pathology Associated With Focal Stenosis of the Main Pancreatic Duct Secondary to Remote Trauma: A Long-term Complication of Seat Belt Pancreatitis.

The radiologic finding of focal stenosis of the main pancreatic duct is highly suggestive of pancreatic cancer. Even in the absence of a mass lesion, focal duct stenosis can lead to surgical resection of the affected portion of the pancreas. We present four patients with distinctive pathology associated with non-neoplastic focal stenosis of the main pancreatic duct. The pathology included stenosis of the pancreatic duct accompanied by wavy, acellular, serpentine-like fibrosis, chronic inflammation with foreign body-type giant cell reaction, and calcifications. In all cases, the pancreas toward the tail of the gland had obstructive changes including acinar drop-out and interlobular and intralobular fibrosis. Three of the four patients had a remote history of major motor vehicle accidents associated with severe abdominal trauma. These results emphasize that blunt trauma can injure the pancreas and that this injury can result in long-term complications, including focal stenosis of the main pancreatic duct. Pathologists should be aware of the distinct pathology associated with remote trauma and, when the pathology is present, should elicit the appropriate clinical history.

Outcome of Seatbelt Education and Safety Program Among Teenagers.

Despite the effectiveness of seatbelts, concerns persist about compliance, especially among teenagers. Survey data from a local high school and registry data from a level 1 trauma center were used to observe seatbelt and motor vehicle accident trends. The survey data was analyzed to gauge student's sentiments on seatbelt education. The trauma center data was analyzed to identify characteristics and trends among teenage motor vehicle accidents. Social media was the most common strategy selected for seatbelt safety awareness. Random seatbelt checks performed over 4 months revealed seatbelt compliance rates of 90%, 93.55%, and 96.94% after education intervention. Trauma center data showed that lack of seatbelt usage resulted in greater morbidity. These findings emphasize the need for targeted interventions. This study provides insights into creating effective education campaigns that can be used to enhance safety belt compliance and potentially reduce injury.

Ocular injuries associated with motor vehicle accidents: long term effects on quality of life.

PURPOSE: To describe the prevalence and outcome of motor vehicle accidents-associated ocular injuries. METHODS: A survey of patients who presented to the emergency room at a level 1 trauma center with motor vehicle accidents-associated ocular injuries. A patient questionnaire and review of clinical notes were conducted for all patients. RESULTS: Of 274 motor vehicle accident victims with ocular injuries who presented to the emergency room, 40 (15%) responded to the survey. Over half of them were driving a vehicle, and most reported wearing a seat belt or a helmet. Most ocular injuries were mild. The most common injuries were bone fractures, subconjunctival hemorrhage, eyelid involvement and corneal injury. Most respondents had no change in vision and perceived their ocular involvement as a minor part of their injury. Most respondents returned to work and to driving within a year. CONCLUSION: Our study sheds light on the details and extent of ocular involvement and the visual ability to perform daily activities following motor vehicle accidents.

Frontal NCAP crash tests with rear-seat occupant.

OBJECTIVES: The initial frontal NCAP tests in 1979 included lap-shoulder belted driver and right-front passenger and lap belted 6-year-old (yo) in the rear. The 35 mph barrier tests were reviewed and analyzed for the restraint performance of the front occupants and child in the rear. METHODS: The initial 100 crash tests (#1-#100) in the NHTSA database were searched for frontal barrier impacts. Fifteen tests met the criteria. There were three tests with the 1980 Chevrolet Citation at 35, 40 and 48 mph. There were 12 other tests with different passenger vehicles at 35 mph into the rigid barrier. The tests included a lap-shoulder belted Hybrid II (Part 572) dummy in the driver and right-front passenger seat and a lap belted 6 yo child dummy (Alderson VIP 6 C) in the center or right rear seat. Vehicle dynamics and occupant kinematics were analyzed, and dummy responses were compared. RESULTS: Vehicle deformation was progressive with impact speed for the Citation tests, leading NHTSA to settle on a 35 mph NCAP speed. The thirteen 35 mph NCAP tests had an average driver HIC of 1099 ± 381 (95th CI 207) and 3 ms chest acceleration of 55.7 ± 16.1 g (95th CI 8.8) with 7 of 13 vehicles failing FMVSS 208 injury criteria. The average right-front passenger HIC was 1179 ± 555 (95th CI 302) and 3 ms chest acceleration was 47.2 ± 14.6 g (95th CI 7.9) with 7 of 13 failing injury criteria. Only four tests (30.8%) passed driver and right-front passenger injury criteria.The responses in the rear seat were significantly worse. The average HIC was 2711 ± 1111 (95th CI 604) and 3 ms chest acceleration was 62.8 ± 10.6 g (95th CI 5.8). The films showed the child's upper body moved forward and rotated downward around the lap belt resulting in severe head impacts on the front seatback, floor, dummy legs or interior. All vehicles failed injury criteria by large margins. Submarining the lap belt was noted in 6 tests. HIC for the rear child was 2.47-times greater than the driver (t = 4.72, p < 0.001) and 2.30-times greater than the right-front passenger (t = 3.64, p < 0.005). CONCLUSIONS: In the 1979 NCAP tests, the child dummy experienced inadequate restraint by the lap belt in the rear seat. The child jackknifed around the lap belt, often submarined, with a severe head impact. No publication of the results has been found. NHTSA did not advise the public of the extremely poor restraint performance, even during the public discussions on the 1986 NTSB recommendation that U.S. vehicle manufacturers install lap-shoulder belts in rear outboard seats. None of the subsequent NCAP tests included a child or adult in the rear until nearly 25 years later.

History of airbag safety benefits and risks.

OBJECTIVE: The history of airbags was reviewed for benefits and risks as they became a supplement to lap-shoulder belts. Sled and crash tests were evaluated and field data was analyzed for airbag effectiveness. Field data on airbag deaths and studies on mechanisms of deployment injury were analyzed. The history was reviewed as airbags evolved from the early 1970s to today. METHODS: Airbag benefits were determined from NHTSA crash tests with unbelted and belted dummies in 40, 48, and 56 km/h (25, 30, and 35 mph) frontal impacts with and without airbags. The literature was reviewed for testing of passive restraints with and without airbags. Recent NCAP tests were compared with earlier tests to determine the change in occupant responses with seatbelts and supplemental airbags in modern vehicles. 1994-2015 NASS-CDS field data was analyzed for MAIS 4 + F injury. Risks were compared for belted and unbelted occupants in frontal impacts by delta V. Airbag risks were identified from field deployments and research. The 1973-76 GM fleet had two deaths due to the occupant being out-of-position (OOP). The mechanisms of injury were determined. From 1989-2003, NHTSA investigated 93 driver, 184 child passenger, and 13 adult passenger airbag deaths. The data was reviewed for injury mechanisms. Second generation airbags essentially eliminated OOP airbag deaths. More recently, three suppliers were linked to airbag rupture deaths. The circumstances for ruptures were reviewed. RESULTS: The risk for serious head injury was 5.495% in drivers and 4.435% passengers in 40-48 km/h (25-30 mph) frontal crash tests without belts or airbags. It was 80.5% lower at 1.073% in drivers and 82.0% at 0.797% in passengers with belts and airbags in 35 mph NCAP crash tests of 2012-20 MY vehicles. NASS-CDS field data showed a 15.45% risk for severe injury (MAIS 4 + F) to unbelted occupants and 4.68% with belted occupants in 30-35 mph frontal crash delta V with airbags, as deployed. The reduction in risk was 69.7% with belt use and airbags deploying in 96.1% of crashes. There were benefits over the range of delta V. Two airbag deaths were studied from the 1970s GM fleet of airbags. The unbelted driver death was caused by punchout force with the airbag cover blocked by the occupant and membrane forces as the airbag wrapped around the head, neck or chest with the occupant close to the inflating airbag. The unbelted child death was from airbag inflation forces from pre-impact braking causing the child to slide forward into the deploying airbag. Research showed that unrestrained children may have 13 different positions near the passenger airbag at deployment. NHTSA investigation of first generation airbag deaths found most driver deaths were females (75.3%) sitting forward on the seat track, close to the driver airbag. Seatbelt use was only 30%. Most child deaths (138, 75.4%) involved no or improper use of the lap-shoulder belts. Of these, 115 deaths involved pre-impact braking. Only 37 (20.2%) children were in child seats with 29 in rear-facing and 8 in forward-facing child seats. Eight child deaths (4.4%) occurred with lap-shoulder belt use. Airbag designs changed. More recently, Takata airbags were related to at least 24 deaths by airbag rupture prompting a recall; the successor company Joyson had an airbag recall. ARC airbags have experienced a chunk of the inflator propelled into the driver during deployment with several deaths leading to a recall. CONCLUSIONS: Airbags are effective in preventing death and injury in crashes. They provide the greatest protection in combination with seatbelt use. NHTSA estimated airbags saved 28,244 lives through 1-1-09 while causing at least 320 deployment deaths, which has prompted improved designs, testing, and recalls.

Frontal NCAP performance and field injury over 40 years.

OBJECTIVES: Vehicle and occupant responses in 35 mph NCAP tests were determined for small-midsize passenger cars grouped around model year (MY) 1980, 1990, 2000, 2010 and 2020. A baseline was established with 1980 vehicles not designed for NCAP. The results of four decades of vehicles designed for NCAP were compared to the baseline. The study also determined the risk for serious injury (MAIS 3 + F) by vehicle model year (MY) using 1989-2015 NASS and 2017-2020 CISS. It explored safety trends in frontal crashes over 50 MYs of vehicles. METHODS: The 1980 baseline group was established with 10 1979-1983 MY passenger cars weighing <1,500 kg. Four decades of vehicle crash tests from five manufacturers established trends in vehicle dynamics and dummy responses over four decades of vehicles designed for NCAP. Triaxial acceleration of the head and chest were reanalyzed for each test to have a consistent set of responses over five decades. The risk for serious injury (MAIS 3 + F) to the driver and front passenger was determined by vehicle MY using 1989-2015 NASS and 2017-2020 CISS with belted and unbelted drivers and right-front passengers. The data was sorted in four MY groups 1961-1989 MY, 1990-1999 MY, 2000-2009 MY and 2010 MY-2021 MY. The risk for MAIS 3 + F injury was determined with standard errors using weighted data. RESULTS: The 1980 NCAP tests brought about changes in vehicle structures and occupant restraints by 1990; however, HIC15 and 3 ms chest acceleration have not changed much the past 20 years since the use of advanced airbags and seatbelts with pretensioner and load-limiters. For the driver, HIC15 dropped 40 ± 19% from the 1980 to 1990 NCAP tests and dropped further to 76 ± 32% in 2020. The percentage drops after 1990 were not statistically significant. The driver 3 ms chest acceleration dropped 18 ± 5% from 1980 to 1990 and plateaued with 22 ± 6% in 2020. For the front passenger, HIC15 dropped 68 ± 52% from the 1980 to 1990 NCAP tests and plateaued at 71 ± 49% in 2020. The passenger 3 ms chest acceleration dropped 13 ± 5% from 1980 to 1990 and has fluctuated with minimal change. Injury risks based on responses show the same initial drop in 1990 and have remained essentially constant. Nothing meaningful has changed in dummy responses in the past 20 years of NCAP testing. The field data found the belted driver MAIS 3 + F risk was 1.66 ± 0.37% in 1961-1989 MY vehicles and 1.39 ± 0.33% in 2010-2021 MY vehicles. For belted right-front passengers, the risk was 1.52 ± 0.39% in 1961-1989 MY vehicles and 1.42 ± 0.46% in 2010-2021 MY vehicles. The field data shows no meaningful change in injury risk in 50 MYs of vehicles. NCAP involves 35-40 mph delta-V, which represents a small fraction, 0.33%, of belted occupant exposure and only 8.6% of severe injury based on 1994-2015 NASS. CONCLUSIONS: The NCAP test lacks field relevance. Manufacturers are merely "tuning" the restraint systems for star ratings without meaningful changes in field injury risks the past 20 years. There are disbenefits of "tuning" safety for a single, high-severity crash when most of the severe injury occurs in lower severity crashes. NHTSA should reevaluate plans to change the dummy to Thor and add BrIC injury criteria to assess NCAP responses. These changes would cause manufacturers to further "tune" structures, restraints and interiors without meaningful effects in real-world crashes.

Ambulance Traffic Crashes in Japan: Characteristics of Casualties and Efforts to Improve Ambulance Safety.

BACKGROUND: An ambulance traffic crash not only leads to injuries among emergency medical service (EMS) professionals but also injures patients or their companions during transportation. We aimed to describe the incidence of ambulance crashes, seating location, seatbelt use for casualties (ie, both fatal and nonfatal injuries), ambulance safety efforts, and to identify factors affecting the number of ambulance crashes in Japan. METHODS: We conducted a nationwide survey of all fire departments in Japan. The survey queried each fire department about the number of ambulance crashes between January 1, 2017, and December 31, 2019, the number of casualties, their locations, and seatbelt usage. Additionally, the survey collected information on fire department characteristics, including the number of ambulance dispatches, and their safety efforts including emergency vehicle operation training and seatbelt policies. We used regression methods including a zero-inflated negative binomial model to identify factors associated with the number of crashes. RESULTS: Among the 726 fire departments in Japan, 553 (76.2%) responded to the survey, reporting a total of 11,901,210 ambulance dispatches with 1,659 ambulance crashes (13.9 for every 100,000 ambulance dispatches) that resulted in a total of 130 casualties during the 3-year study period (1.1 in every 100,000 dispatches). Among the rear cabin occupants, seatbelt use was limited for both EMS professionals (n = 3/29, 10.3%) and patients/companions (n = 3/26, 11.5%). Only 46.7% of the fire departments had an internal policy regarding seatbelt use. About three-fourths of fire departments (76.3%) conducted emergency vehicle operation training internally. The output of the regression model revealed that fire departments that conduct internal emergency vehicle operation training had fewer ambulance crashes compared to those that do not (odds of being an excessive zero -2.20, 95% CI: -3.6 to -0.8). CONCLUSION: Two-thirds of fire departments experienced at least one crash during the study period. The majority of rear cabin occupants who were injured in ambulance crashes were not wearing a seatbelt. Although efforts to ascertain seatbelt compliance were limited, Japanese fire departments have attempted a variety of methods to reduce ambulance crashes including internal emergency vehicle operation training, which was associated with fewer ambulance crashes.

Surveillance methods and interventions implemented in American Indian and Alaska Native communities to increase child restraint device and seat belt use in motor vehicles: a systematic review.

BACKGROUND: American Indian/Alaska Native (AI/AN) children are disproportionately affected by injuries and deaths related to motor vehicle crashes. We aimed to synthesise published evidence on surveillance methods and interventions implemented in AI/AN communities and analyse characteristics that make them successful in increasing child restraint devices and seat belt use. METHODS: Studies were collected from the PubMed, Scopus, and TRID databases and the CDC Tribal Road Safety website, Community Guide, and Indian Health Service registers. Included studies collected primary data on AI/AN children (0-17) and reported morbidity/mortality outcomes related to child restraint devices or seat belt use. Studies with poor methodological quality, published before 2002, whose data were collected outside of the USA, or were non-English, were excluded. Checklists from the Joanna Briggs Institute were used to assess the risk of bias. In the synthesis of results, studies were grouped by whether a surveillance method or intervention was employed. RESULTS: The final review included 9 studies covering 72 381 participants. Studies conducted surveillance methods, interventions involving law enforcement only and multipronged interventions. Multipronged approaches were most effective by using the distribution of child restraint devices combined with at least some of the following components: educational programmes, media campaigns, enactment/enforcement of child passenger restraint laws, incentive programmes and surveillance. DISCUSSION: Although this review was limited by the number and quality of included studies, available resources suggest that we need multipronged, culturally tailored and sustainable interventions fostered by mutually beneficial and trusting partnerships. Continued investment in AI/AN road safety initiatives is necessary.

Female vs. male relative fatality risk in fatal motor vehicle crashes in the US, 1975-2020.

Motor vehicle accidents are the leading cause of death for young adults 18-29 years old worldwide, resulting in nearly 1 million years of life lost annually in the United States. Despite improvements in vehicle safety technologies, young women are at higher risk of dying in car crashes compared with men in matched scenarios. Vehicle crash testing primarily revolves around test dummies representative of the 50th percentile adult male, potentially resulting in these differences in fatality risk for female occupants compared to males. Vehicle occupants involved in fatal car crashes were matched using seating location, vehicle type, airbag deployment, seatbelt usage, and age. The relative risk for fatality (R) between males and females was calculated using a Double Pair Comparison. Young women (20s-40s) are at approximately 20% higher risk of dying in car crashes compared with men of the same age in matched scenarios. In passenger cars, 25-year-old female occupants in passenger car crashes from 1975-2020 exhibit R = 1.201 (95% CI 1.160-1.250) compared to 25-year-old males, and R-1.117 (95% CI 1.040-1.207) for passenger car crashes from 2010-2020. This trend persists across vehicle type, airbag deployment, seatbelt use, and number of vehicles involved in a crash. Known sex-based differences do not explain this large risk differential, suggesting a need for expanded test methodologies and research strategies to address as-yet unexplored sex differences in crash fatalities. These differences should be further investigated to ensure equitable crash protection.

Education, incentive, and engineering-based interventions to promote the use of seat belts.

BACKGROUND: Over 1.3 million people die each year as a result of traffic collisions and hundreds of thousands of others are permanently and seriously injured. Most of these deaths occur in low- and middle-income countries, where mortality rates can be up to 10 times higher than those of some high-income countries. Seat belts are designed to accomplish two key functions - to prevent the occupant from being ejected from the vehicle by the force of impact, and to extend the time that the decelerating force is applied to a person. Seat belts also spread the area of impact both to larger and less vulnerable parts of the body. Since the 1950s, seat belts have been factory-fitted to most vehicles, and today around 90% of high-income countries have adopted seat belt legislation that makes it mandatory for some, if not all, vehicle occupants to wear seat belts. However, the simple passing of laws is not sufficient to ensure seat belt use, and, while the enforcement of seat belt laws does increase seat belt use, other interventions have been developed to encourage voluntary - and hence sustainable - behaviour change. OBJECTIVES: To evaluate the benefits of behavioural-change interventions (educational-based, incentive-based, engineering-based, or a combination, but not enforcement-based) that promote the use of seat belts, and to determine which types of interventions are most effective. SEARCH METHODS: On 9 August 2022, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), OvidSP Embase, OvidSP MEDLINE, 14 other databases, and clinical trials registers. We also screened reference lists and conference proceedings, searched websites of relevant organisations, and contacted road safety experts. The search was performed with no restrictions in terms of language and date of publication. SELECTION CRITERIA: We included randomised controlled trials (RCTs), both individually randomised and cluster-randomised, that evaluated education, engineering, incentive-based interventions (or combinations) that promoted seat belt use. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the eligibility of RCTs, evaluated the risk of bias, and extracted data. We performed a narrative synthesis based on effect direction due to the heterogeneity observed between RCTs and reported the synthesis in accordance with reporting guidelines for systematic reviews without meta-analysis, as appropriate. We assessed the certainty of the evidence using the GRADE approach. We analysed data on the primary outcome, frequency of wearing a seat belt. None of the included RCTs reported the other primary outcome, crash-related injury rate or the secondary outcome, crash-related mortality rates of interest in this review. MAIN RESULTS: We included 15 completed RCTs (12 individual, parallel-group, and three cluster) that enroled 12,081 participants, published between 1990 and 2022. Four trials were published between 2019 and 2022, and the remaining trials were published 10 or more years ago. We also identified four ongoing RCTs. Thirteen RCTs were conducted in the USA. Trials recruited participants from various sites (worksites, schools, emergency departments, a residential retirement community, and primary care settings) and different age groups (adults, late adolescents, early adolescents, and dyads). Thirteen trials investigated educational interventions, one of which used education in addition to incentives (one of the intervention arms) measured through participant self-reports (12) and observation (one), and two trials investigated engineering-based interventions measured through in-vehicle data monitor systems at various follow-up periods (six weeks to 36 months). We grouped RCTs according to types of education-based interventions: behavioural education-based, health risk appraisal (HRA), and other education-based interventions. The evidence suggests that behavioural education-based (four trials) interventions may promote seat belt use and HRA interventions (one trial) likely promote seat belt use in the short term (six weeks to nine months). Four of the six trials that investigated behavioural education-based interventions found that the intervention compared to no or another intervention may promote seat belt use. These effects were measured through participant self-report and at various time points (six-week to 12-month follow-up) (low-certainty evidence). One of the three trials investigating HRA only or with additional intervention versus no or another intervention showed observed effects likely to promote seat belt use (moderate-certainty evidence). The evidence suggests that engineering-based interventions using vehicle monitoring systems (with in-vehicle alerts and with or without notifications/feedback) may promote the use of seat belts. One trial showed that engineering interventions (in-vehicle alerts and feedback) may promote seat belt use while the other showed unclear effects in two of the three intervention groups (low-certainty evidence). Both trials had small sample sizes and high baseline seat belt use. AUTHORS' CONCLUSIONS: The evidence suggests that behavioural education-based interventions may promote seat belt use and HRA (including incentives) with or without additional interventions likely promote seat belt use. Likewise, for engineering-based interventions using in-vehicle data monitor systems with in-vehicle alerts, with or without notifications/feedback the evidence suggests the interventions may promote the use of seat belts. Well-designed RCTs are needed to further investigate the effectiveness of education and engineering-based interventions. High-quality trials that examine the potential benefits of incentives to promote seat belt use, either alone or in combination with other interventions, as well as trials to investigate other types of interventions (such as technology, media/publicity, enforcement, insurance schemes, employer programmes, etc.) to promote the use of seat belts, are needed. Evidence from low- and middle-income economies is required to improve the generalisability of the data. In addition, research focused on determining which interventions or types of interventions are most effective in different population groups is needed.

Are crash causation studies the best way to understand system failures - Who can we blame?

The search for common and serious single causes of road crashes naturally leads to a concentration on the road user. This is supported by a legal framework in the search for the main cause and the suspect for this cause. In prevention, we havefor decades been more inclined to look for systematic improvements of all elements of the road transport system, and we direct the recommendations for actions towards system designers, organizations, products and services. In this paper the discussion about causation and prevention is broadened in the light of Vision Zero and its approach to prevention of serious and fatal injuries. We also discuss the Swedish judicial system and why the prevention approach has not been legislated or even generally accepted. Occupational health and safety legislation and road rules are compared, as well as how sustainability practices and reporting are tools to apply prevention where organizations have a natural sphere of influence that could mitigate deaths and serious injuries within value chains. It is recommended that we stop using the term causation as it is only directing actions in one direction. There is a risk that the focus on causation, in particular single causes, will deviate actions away from robust prevention countermeasures such as increased seat belt use, relevant speed limits, and well functioning roundabouts and median barriers. Furthermore, there is also a risk that important preventative actions from organizations are overlooked.

The Influence of a Booster Seat on the Motion of the Reclined Small Female Anthropomorphic Test Device in Low-Acceleration Far-Side Lateral Oblique Impacts.

Belt-positioning booster (BPB) seats may prevent submarining in reclined child occupants in frontal impacts. BPB-seated child volunteers showed reduced lateral displacement in reclined seating in low-acceleration lateral-oblique impacts. As submarining was particularly evident in reclined small adult female occupants, we examined if a booster seat could provide similar effects on the kinematics of the small female occupant to the ones found on the reclined child volunteers in low-acceleration far-side lateral oblique impacts. The THOR-AV-5F was seated on a vehicle seat on a sled simulating a far-side lateral-oblique impact (80 deg from frontal, maximum acceleration ∼2 g, duration ∼170 ms). Lateral and forward head and trunk displacements, trunk rotation, knee-head distance, seatbelt loads, and head acceleration were recorded. Three seatback angles (25 deg, 45 deg, 60 deg) and two booster conditions were examined. Lateral peak head and trunk displacements decreased in more severe reclined seatback angles (25-36 mm decrease compared to nominal). Forward peak head, trunk displacements, and knee-head distance were greater with the seatback reclined and no BPB. Knee-head distance increased in the severe reclined angle also with the booster seat (>40 mm compared to nominal). Seat belt peak loads increased with increased recline angle with the booster, but not without the booster seat. Booster-like solutions may be beneficial for reclined small female adult occupants to reduce head and trunk displacements in far-side lateral-oblique impacts, and knee-head distance and motion variability in severe reclined seatback angles.

Prevalence of intra-abdominal injury among patients with seatbelt signs, a systematic review and meta-analysis.

INTRODUCTION: The advancement of seat belts have been essential to reducing morbidity and mortality related to motor vehicle collisions (MVCs). The "seat belt sign" (SBS) is an important physical exam finding that has guided management for decades. This study, comprising a systematic review and random-effects meta-analysis, asses the current literature for the likelihood of the SBS relating to intra-abdominal injury and surgical intervention. METHODS: PubMed and Scopus databases were searched from their beginnings through August 4, 2023 for eligible studies. Outcomes included the prevalence of intra-abdominal injury and need for surgical intervention. Cochrane's Risk of Bias (RoB) tool and the Newcastle-Ottawa Scale (NOS) were applied to assess risk of bias and study quality; Q-statistics and I2 values were used to assess for heterogeneity. RESULTS: The search yielded nine observational studies involving 3050 patients, 1937 (63.5%) of which had a positive SBS. The pooled prevalence of any intra-abdominal injury was 0.42, (95% CI 0.28-0.58, I2 = 96%) The presence of a SBS was significantly associated with increased odds of intra-abdominal injury (OR 3.62, 95% CI 1.12-11.6, P = 0.03; I2 = 89%), and an increased likelihood of surgical intervention (OR 7.34, 95% CI 2.03-26.54, P < 0.001; I2 = 29%). The measurement for any intra-abdominal injury was associated with high heterogeneity, I2 = 89%. CONCLUSION: This meta-analysis suggests that the presence of a SBS was associated with a statistically significant higher likelihood of intra-abdominal injury and need for surgical intervention. The study had high heterogeneity, likely due to the technological advancements over the course of this study, including seat belt design and diagnostic imaging sensitivity. Further studies with more recent data are needed to confirm these results.