Correlates of front-seat passengers' non-use of seatbelts at night

Are out-of-state drivers more seatbelt compliant than in-state drivers in the United States?

INTRODUCTION

This study explored the seatbelt use among in-state and out-of-state drivers in relation to their personal (age, gender, license status, etc.) and crash characteristics (time, location, roadway factors, etc.) using crash data over a 10-year period (2010-2019) from the Fatality Analysis Reporting System (FARS).

METHOD

Comparison of seatbelt use between the two groups (in-state vs. out-of-state drivers) were conducted using Z-test statistics. Logistic regression models were developed to examine the probability of seatbelt use among each group.

RESULTS

New findings in this study showed that out-of-state drivers were 5% more likely than in-state drivers to use seatbelts. Regardless of the driver's age, gender, license status, vehicle type, and injury severity, seatbelt use was significantly higher among out-of-state drivers. Moreover, irrespective of the location (rural or urban), the season (time, day, or month), road type (arterial, local streets, etc.), and jurisdictional seatbelt law (primary or secondary), out-of-state drivers were more seatbelt compliant than in-state drivers. Finally, out-of-state drivers traveling from states with secondary/no seatbelt laws exhibited higher seatbelt compliance rate in primary seatbelt law states than in states with less strict laws (i.e., secondary/no law).

PRACTICAL APPLICATIONS

The findings in this study are critical to addressing a myriad of policy questions related to seatbelt laws and seatbelt use. Future research should focus on the disparity in seatbelt use between the two groups and determine intervention strategies that are effective at promoting seatbelt use across the United States. Additionally, given the significant differences in driver seatbelt use behavior based on the type of seatbelt law, if states with less strict laws upgrade to primary seatbelt laws, there likely will be increases in seatbelt compliance in those states.

Young adults in motor vehicle collisions in Norway: user safety errors observed in majority of cases with severe or fatal injuries

PURPOSE

We performed a multidisciplinary investigation of young adults involved in motor vehicle collisions (MVCs) to elucidate injury mechanisms and the role of passive safety equipment such as seat belts and airbags.

METHODS

MVCs resulting in death or serious injuries to the driver or passengers aged 16-24 years in southeastern Norway during 2013-2016 were investigated upon informed consent. We assessed the crash scene, the motor vehicle (MV) interior and exterior, and analyzed data from medical records, forensic autopsies and reports from police and civil road authorities.

RESULTS

This study included 229 young adult occupants involved in 212 MVCs. The Maximum Abbreviated Injury Scale (MAIS) score was ≥2 in 111 occupants, of which 22 were fatalities. In 59% (65/111) of the cases with MAIS score ≥2 injuries, safety errors and occupant protection inadequacies were considered to have contributed to the injury outcome. Common errors were seatbelt non-use and misuse, carrying insecure luggage, and the seat back being too reclined. MAIS score ≥2 head/neck injuries were observed in side impacts despite correct seatbelt use, related to older MVs lacking side airbag curtains. The independent risk factors for MAIS score ≥2 injuries included not using a seatbelt, driving under the influence of alcohol or drugs, nighttime driving, side impacts, heavy collision partner, and MV deformation.

CONCLUSION

User safety errors (not using a seatbelt, seatbelt misuse, excessive seat-back reclining, and insecure cargo) and a lack of occupant protection in older MVs resulted in young adults sustaining severe or fatal injuries in MVCs.

The relationship between driver and passenger's seatbelt use: a bivariate probit analysis

Vehicle seatbelt has been shown to have a beneficial impact on occupants. However, some occupants do not use the seatbelt when inside a moving vehicle. Despite the numerous investigation on the risk factors associated with seatbelt use by occupants, little is known about the relationship between driver and passenger seatbelt use. This gap is analyzed with road side observational survey data on driver and front-right seat passenger's seatbelt use behaviour using bivariate probit model. The use of the bivariate probit model is based on the premise that the front-right passenger's seatbelt use is endogenously related to that of the driver. Out of the 5,433 vehicles observed, the prevalence rate of driver and front-right passengers' seatbelt use were 81% and 33%, respectively. In addition, there is a positive relationship between driver and passenger's seatbelt use with correlation coefficient of 0.53. Thus, the unobserved factors that influence the probability of a driver seatbelt use also influence their front-right passenger's seatbelt use propensity.

Injury risk assessment based on pre-crash variables: The role of closing velocity and impact eccentricity

Thorough evaluations on injury risk (IR) are fundamental for guiding interventions toward the enhancement of both the road infrastructure and the active/passive safety of vehicles. Well-established estimates are currently based on IR functions modeled on post-crash variables, such as velocity change sustained by the vehicle (ΔV); thence, these analyses do not directly suggest how pre-crash conditions can be modified to allow for IR reduction. Nevertheless, ΔV can be disaggregated into two contributions which enable its apriori calculation, based only on the information available at the impact instant: the Crash Momentum Index (CMI), representing impact eccentricity at collision, and the closing velocity at collision (V_r). By extensively employing the CMI indicator, this work assesses the overall influence of impact eccentricity and closing velocity on the risk for occupants to sustain a serious injury. As CMI synthesizes indications regarding ΔV, its use can be disjointed from the ΔV itself for the derivation of high-quality IR models. This feature distinguishes CMI from the other eccentricity indicators available at the state-of-the-art, allowing for the contribution of eccentricity on IR to be completely isolated. Because of this element of originality, special attention is given to the CMI variable throughout the present work. Based on data extracted from the NASS/CDS database, the influence of the CMI and V_r variables on IR is specifically highlighted and analyzed from several perspectives. The feature ranking algorithm ReliefF, whose use is unprecedented in the accident analysis field, is first employed to assess importance of such impact-related variables in determining the injury outcome: if compared to vehicle-related and occupant-related variables (as category and age, respectively), the higher influence of CMI and V_r is initially highlighted. Secondly, the relevance of CMI and V_r is confirmed by fitting different predictive models: the fitted models which include the CMI predictor perform better than models which neglect the CMI, in terms of classical evaluation metrics. As a whole, considering the high predictive power of the proposed CMI-based models, this work provides valuable tools for the apriori assessment of IR.

Investigating traffic fatality trends and restraint use among rear-seat passengers in the United States, 2000-2016

INTRODUCTION

Motor-vehicle crash is one of the leading causes of unintentional injury death in the United States. Previous studies focused on fatalities among drivers and front-seat passengers, with a limited number of studies examining rear-seat passenger fatalities. The objectives of this study were to assess trends in rear-seat passenger motor-vehicle fatalities in the United States from 2000 to 2016 and to identify demographic factors associated with being unrestrained among fatally injured rear-seat passengers.

METHODS

Rear-seat passenger fatality data were obtained from the Fatality Analysis Reporting System (FARS) database. The fatality rate ratios for overall rear-seat passengers and for different age and sex groups were determined by comparing fatality rates in 2000 and 2016 using random effects models. Risk ratios of being unrestrained for age and sex groups were obtained using general estimating equations.

RESULTS

Compared to 2000, the overall rear-seat passenger fatality rate in 2016 decreased by 44% (95% confidence interval [CI]: 39-49%). In particular, the fatality rate among rear-seat passengers decreased more in males than females, and passengers aged 14-19 years experienced a larger decline than all other age groups. Fatally injured male rear-seat passengers had a higher risk of being unrestrained (adjusted risk ratio: 1.06, 95% CI: 1.04-1.07) than their female counterparts, and both youngest (≤13 years) and oldest (65-85 years) passengers were less likely to be unrestrained than those aged 20-64 years.

CONCLUSIONS

Overall, fatality rates among rear-seat passengers have declined, with differential degrees of improvement by age and sex. Practical Applications: Continued restraint use enforcement campaigns targeted at teenagers and males would further preserve them from fatal injuries and improve traffic safety for the overall population.

Nighttime seat belt use among front seat passengers: Does the driver's belt use matter?

INTRODUCTION AND METHOD

We explored the relationship between nighttime seat belt use of right-front passengers and their drivers using observational data from 33,310 vehicles in east Tennessee during March 2015 - May 2017.

RESULTS

Overall, nighttime passenger seat belt use varied by 50 percentage points from 92% when drivers were belted to 42% when drivers were not belted, suggesting that part-time seat belt users can be heavily influenced by the seat belt status of their traveling companions. When stratified by vehicle type and sex, passenger seat belt use by driver seat belt status varied as much as 74 percentage points from 96% to 22%. Passenger seat belt use was typically lower when riding with unbelted same-sex drivers than when riding with unbelted drivers of the opposite sex. Conclusions and Practical Applications: This finding suggests that the role of peer influence in decision-making about seat belt use may differ depending on the sex of a vehicle driver and his or her passengers. Further research is warranted to explore this finding as well as other social and cultural influences that have not been fully examined in seat belt research.