Fatal Motor Vehicle Research Articles

Obesity and motor vehicle deaths: a panel-data analysis

PurposeThis paper analyzes the impact of obesity on the probability of a motor vehicle fatality (highway death rate) and on its component probabilities: the probability of a fatality, given a crash (vulnerability rate) and the probability of a crash (crash rate).Design/methodology/approachUsing state-level data for 1995–2015, the paper estimates models explaining all three rates. Explanatory factors include obesity and a representative set of potential determinants.FindingsResults indicate that obesity has a statistically significant positive relationship with the highway death rate and the crash rate. Also having a statistically significant positive association with at least one of the three rates are the proportions of young and old drivers, alcohol consumption, the ratio of rural to urban vehicle miles and temperature. Factors with a statistically significant negative relationship with at least one of the rates include primary seat belt laws and precipitation. In 2016, a total of 928 traffic fatalities could have been avoided if obesity rates decreased by one percentage point.Practical implicationsSeat belts and crash dummies should be better designed to fit and represent those with higher BMIs, and education efforts to increase seat belt use should be supplemented with information about the adverse impact of obesity on highway safety.Originality/valueThis paper uses 21 years of state-level information, including socio-economic and regulation data, and contributes to the existing research on the relationship between obesity and highway safety.

Effectiveness of child restraint legislation to reduce motor vehicle related serious injuries and fatalities: A national interrupted time series analysis

Children that are unrestrained while travelling in a motor vehicle are more vulnerable to serious injury and death. The greatest levels of crash protection are achieved when children use the most age or size appropriate form of restraint. In this study, we aimed to examine the effectiveness of the introduction of age-appropriate child restraint legislation on serious and fatal injury in five Australian states and territories. For this interrupted time series analysis, we used a segmented regression method to assess the association between the implementation of child-restraint legislation and motor-vehicle related serious injuries and fatalities using data obtained from transport authorities in each jurisdiction. We estimated the change in annual rates after the implementation of legislation with the number of motor-vehicle accidents resulting in fatalities or serious injuries as the outcome, and the total number of injuries (minor, serious and fatal) as an offset in the model. We identified 10882 motor-vehicle related crashes resulting in fatalities (n = 188), serious injuries (n = 1730) and minor injuries (n = 8964). In NSW and VIC, the rate ratio was statistically significant and positive, indicating an increase in the rate of serious injuries and fatalities in the period post-legislation compared to the period prior to legislation. In all other states and territories, we did not find a statistically significant effect of legislation Road safety programs incorporating interventions targeted at increasing awareness of optimal restraint practices, strengthened enforcement and measures to improve the affordability of restraints are needed to support legislation.

Using a novel data linkage approach to investigate potential reductions in motor vehicle crash severity – An evaluation of strategic highway safety plan emphasis areas

Introduction: With the significant number of motor-vehicle fatalities occurring on the nation’s roadways in recent years, there exists a need to integrate a more complete range of data sources, available at a regional or statewide level, to effectively evaluate existing safety concerns and quantify their impacts. Crash data alone does not provide ample crash-associated citation, injury, and roadway characteristics; therefore, a more cohesive dataset is required to accurately and completely analyze the true impacts of motor-vehicle crashes. Previously developed strategies linked crash data with citation and roadway inventory data to enhance the identification and optimization of highway safety strategies. Method: The main objective of this research focused on developing a new deterministic linkage between crash and Emergency Medical Services (EMS) data, by utilizing the Massachusetts Crash Data System (CDS) and the Massachusetts Ambulance Trip Record Information System (MATRIS). Results: After several iterations of match criterion, the validated linkage successfully matched 58.3% of MATRIS records (containing an Injury Cause of Motor Vehicle Crash) to a CDS person record (55011 linked pairs, between 2014 and 2016). The data linkage provided significant insight into injury trends in several highway safety emphasis areas such as roadway departure, speeding-related, and distraction-affected crashes. The findings from this research are twofold: (1) an established process for linking previously separate data sets, and (2) a mechanism for analysis that provides decision-makers and safety professionals with a better measure of crash outcomes.

Fatal childhood injuries in Finland between 1971 and 2017

BackgroundThe injury mortality rates around the globe show considerable country-to-country differences and the rates have decreased at very different speeds. In Finland, the proportion of total mortality attributed to injuries has been one of the highest in the European Union. The purpose of the present study was to examine the 47-year nationwide trend and the male to female ratio in the number and incidence of fatal injuries among 0 to 14-year-old children in Finland.MethodsThe data were obtained from the Official Cause-of-Death Statistics of Finland during 1971–2017. The main categories for unintentional injury deaths were road traffic injuries, water traffic injuries, falls, drownings, and poisonings. For intentional injury deaths, the main categories were suicides and homicides.ResultsIn 1971, there were 109 fatal injuries in girls and 207 in boys, while in 2017, these numbers had reduced to 9 and 12. The corresponding incidences (per 100,000 children per year) were 20.1 and 2.1 for girls, and 36.7 and 2.6 for boys, respectively. During the study period overall male to female injury incidence ratio decreased from 1.8 to 1.2. The greatest decline occurred in the number of fatal motor vehicle injuries. In 1971, the incidence of intentional deaths (suicides and homicides) was 2.6 in girls and 2.7 in boys, while in 2017 these numbers were 0.9 and 0.4, respectively.ConclusionsThis nationwide study confirms that the number and incidence rates of childhood injury deaths have reduced till current days and are already below the average in Europe.

The impact of state laws on motor vehicle fatality rates, 1999-2015.

Motor vehicle crash (MVC) fatalities have been declining while states passed various legislation targeting driver behaviors. This study assesses the impact of state laws on MVC fatality rates to determine which laws were effective. Publically available data were collected on driver-related motor vehicle laws, law strengths, enactment years, and numbers of verified-trauma centers. Prospective data on crash characteristics and MVC fatalities 16 years or older from Fatality Analysis Reporting System 1999 to 2015 (n = 850) were obtained. Generalize Linear Autoregressive Modeling was used to assess the relative contribution of state laws to the crude MVC fatality rate while controlling for other factors. Lowering the minimum blood alcohol content (BAC) was associated with largest declines for all ages, especially the older cohorts: 16 years to 20 years (B = 0.23; p < 0.001), 21 years to 55 years (B = 1.7; p < 0.001); 56 years to 65 years (B = 3.2; p < 0.001); older than 65 years (B = 4.1; p < 0.001). Other driving under the influence laws were also significant. Per se BAC laws accompanying a reduced BAC further contributed to declines in crude fatality rates: 21 years to 55 years (B = -0.13; p < 0.001); older than 65 years (B = -0.17; p < 0.05). Driving under the influence laws enhancing the penalties, making revocation automatic, or targeting social hosts had mixed effects by age. Increased enforcement, mandatory education, vehicle impoundment, interlock devices, and underage alcohol laws showed no association with declining mortality rates. Red light camera and seatbelt laws were associated with declines in mortality rates for all ages except for older than 65 years cohort, but speed camera laws had no effect. Graduated Driver License laws were associated with declines for 16 years to 21 years (B = -0.06; p < 0.001) only. Laws targeting specific risks (elderly, motorcycles, marijuana) showed no effect on declining MVC mortality rates during the study period. States have passed a wide variety of laws with varying effectiveness. A few key laws, specifically laws lowering allowable BAC, implementing red light cameras, and mandating seatbelt use significantly reduced MVC mortality rates from 1999 to 2015. Simply adding more laws/penalties may not equate directly to lives saved. Continued research on state laws will better inform policy makers to meet evolving public health needs in the management of MVC fatalities. Epidemiological, Level III.

State-level seat belt use in the United States, 2011–2016: Comparison of self-reported with observed use and use by fatally injured occupants

Introduction: Despite 49 states and the District of Columbia having seat belt laws that permit either primary or secondary enforcement, nearly half of persons who die in passenger vehicle crashes in the United States are unbelted. Monitoring seat belt use is important for measuring the effectiveness of strategies to increase belt use. Objective: Document self-reported seat belt use by state seat belt enforcement type and compare 2016 self-reported belt use with observed use and use among passenger vehicle occupant (PVO) fatalities. Methods: We analyzed the Behavioral Risk Factor Surveillance System (BRFSS) self-reported seat belt use data during 2011–2016. The Pearson correlation coefficient (r) was used to compare the 2016 BRFSS state estimates with observed seat belt use from state-based surveys and with unrestrained PVO fatalities from the Fatality Analysis Reporting System. Results: During 2011–2016, national self-reported seat belt use ranged from 86–88%. In 2016, national self-reported use (87%) lagged observed use (90%) by 3 percentage points. By state, the 2016 self-reported use ranged from 64% in South Dakota to 93% in California, Hawaii, and Oregon. Seat belt use averaged 7 percentage points higher in primary enforcement states (89%) than in secondary states (82%). Self-reported state estimates were strongly positively correlated with state observational estimates (r = 0.80) and strongly negatively correlated with the proportion of unrestrained PVO fatalities (r = −0.77). Conclusion: National self-reported seat belt use remained essentially stable during 2011–2016 at around 87%, but large variations existed across states. Practical Applications: If seat belt use in secondary enforcement states matched use in primary enforcement states for 2016, an additional 3.98 million adults would have been belted. Renewed attention to increasing seat belt use will be needed to reduce motor-vehicle fatalities. Self-reported and observational seat belt data complement one another and can aid in designing targeted and multifaceted interventions.

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.

The association between legalization of cannabis use and traffic deaths in Uruguay.

While cannabis use has been found to impair motor vehicle driving, the association between cannabis legalization and motor vehicle fatalities is unclear. In Uruguay in December 2013, cannabis for recreational purposes was legalized. This study assessed the association between implementation of this law and changes in traffic fatality rates. Interrupted time-series analysis of traffic fatality rates of light motor vehicle drivers and motorcyclists in urban and rural settings. Changes are reported as step and trend effects against modeled trends in the absence of legalization. Uruguay, Montevideo and four rural provinces (Colonia, Florida, Río Negro and San José) from 1January 2012 to 31December 2017. Cases and measurement Weekly traffic fatalities of light motor vehicle drivers and motorcyclists per type of vehicle. Data were gathered from the National Road Safety Agency of Uruguay and the Ministry of Transport and Public Works, respectively. Cannabis legalization was associated with a 52.4% immediate increase [95% confidence interval (CI)=11.6, 93.3, P=0.012] in the light motor vehicle driver's fatality rate. However, no significant change in the motorcyclists' fatality rate was observed. In Montevideo the legislation was associated with an absolute increase in its light motor vehicle driver's fatality rate by 0.06 (95% CI=0.01, 0.11, P = 0.025), but no significant associations were observed in rural settings. In Uruguay, the 2013 legislation legalizing recreational cannabis consumption may have been associated with an increase in fatal motor vehicle crashes, particularly in light motor-vehicle drivers and urban settings.

Driving Me to Drink: The Relationship Between Ride-Hailing Services and Alcohol Consumption

Background: Alcohol consumption is associated with a wide range of adverse health consequences and is a leading cause of preventable deaths. Ride hailing services such as Uber have been found prevent alcohol-related motor vehicle fatalities. These services may, however, facilitate alcohol consumption generally and binge drinking in particular. Objective: To measure the impact of ride hailing services on the extent and intensity of alcohol consumption. We allow these associations to depend on population density as the utilization of ride hailing services likely varies across markets. Methods: We exploit the phased rollout of the ride hailing platform Uber using a difference in differences approach. We use this variation to measure changes in alcohol consumption among a local population following Uber’s entry. Data are drawn from Uber press releases to capture platform entry and the Behavioral Risk Factor Surveillance Systems (BRFSS) Annual Survey measures alcohol consumption in 113 metropolitan areas. Models are estimated using fixed effects Poisson regression. Pre- and post-entry trends are used to validate this approach. Results: Ride hailing has no effect on the extent of alcohol consumption in high- 0.61 [95% CI: - 0.05% to 1.28%] or low- 0.61 [95% CI: -0.05% to 1.28%] density markets, but increases the binge drinking rate by 0.71 [95% CI: 0.13% to 1.29%]. This corresponds to a 4% increase in binge-drinking within an MSA. Conclusion: Ride hailing services appear to stimulate risky behavior, in the form of binge drinking, which has been associated with a wide array of adverse health outcomes. Drunk driving rates have fallen for more than a decade, while the incidence of binge drinking has continued to climb. Both trends may be accelerated by ride hailing services. This suggests that health information messaging should increase emphasis on the direct dangers of alcohol consumption and binge drinking.

A short survival time after last psychiatric hospitalization in drivers with psychotic disorder killed in fatal motor vehicle accidents

BackgroundResearch-based evidence on patients with psychotic disorders involved in fatal motor vehicle accidents (FMVA) remains limited. The current study analyzes the characteristics of FMVA drivers, who had been hospitalized due to psychotic disorders within a five-year-time-period prior to their death in traffic accidents. Material and methodsData sources included three national registers: The Finnish Database of Road and Cross-Country Accidents, the Care Register for Health Care and the National Cause of Death Register. The register-linkage was made using personal identity codes, unique for each Finnish citizen. The initial study population consisted of 4930 drivers killed in FMVA in Finland between the years 1990–2011. A total of 94 (1.9%) Finnish drivers had a hospital-diagnosed psychotic disorder made during the five years preceding their FMVA. The psychotic disorders of the study subjects were categorized into: schizophrenia (n = 27, 28.7%), other specified psychoses (n = 39, 41.5%) and unspecified psychoses (n = 28, 29.8%). ResultsAbout one half of the FMVA drivers with schizophrenia or unspecified psychoses and 41% of those with other specified psychoses had been discharged from psychiatric care within three months prior to their death in traffic accidents. ConclusionsBased on our study findings and the lack of concise guidelines for assessing psychotic patients' fitness-to-drive, we recommend a minimum temporary driving restriction of three months for all patients after hospitalization for psychosis.

The epidemiology of pedestrian fatalities and substance use in Georgia, United States, 2007–2016

Though U.S. motor vehicle crashes as a whole have decreased over the past few years, fatalities among vulnerable road users have increased. Pedestrian deaths rose nationally by 27% between 2007 and 2016 accounting for 16% of all motor vehicle fatalities. This increase continues to burden transportation specialists, public health professionals, and community stakeholders. Potential risk factors include characteristics of the built environment, distractions, and pedestrians’ use of alcohol and drugs. Pedestrian deaths in Georgia, United States, increased 40% between 2014 and 2016 while drug overdose deaths have increased by 18% during the same period. Concurrent increases in mortality due to pedestrian fatalities and drug overdoses make Georgia a natural environment in which to describe the proximity of drugs among pedestrian fatalities, a topic largely overlooked by the literature. This study explores the epidemiology of pedestrian fatalities in Georgia over a 10-year period with an emphasis on reported substance use among cases. The study employed 10-year data from the Fatality Analysis Reporting System (FARS) administered by the National Highway Traffic Safety Administration. Descriptive methods were used to explore drug screens by person, place, and time. We also examined trends in total drug screens over the examination period. Between 2007 and 2016, 1781 pedestrian crashes were reported to FARS; the fatality rate for this period was 94.5%. Of these, most were male with Blacks and Whites equally represented. Ages 15–64 accounted for 81.1% of cases with most occurring in the Atlanta Metropolitan area. When adjusted for population, one finds higher rates in more rural areas of the state. Data revealed that testing for the presence of drugs occurred among half of reported cases. Of those testing positive, five drug categories emerged; stimulants (45.8%), cannabinoids (21.5%), narcotics (including opioids) (14.1%), depressants (12.1%), and “Other Drugs” (6.3%). Positive drug screens across all drug classifications increased by 178.1% between 2007 and 2016. These findings suggest the need for state-wide policies designed to promote more consistent screening among pedestrians involved in motor vehicle crashes as well as diligence in understanding the role played by drugs among this population. Additional investigation should be conducted to tease out the presence of category-specific drugs among pedestrians. Understanding the epidemiology of pedestrian fatalities in the state, especially in relation to substance use, serves as a first step toward implementing localized preventive efforts.

Cigarette prices and driving fatalities among youths

Deaths from motor vehicle crashes are a leading cause of unintentional deaths in the United States. This paper investigates the effect of increases in cigarette taxes and prices following the Master Settlement Agreement (MSA) on non-alcohol and alcohol-related motor vehicle fatalities among youths. I find that increases in cigarette taxes and prices are associated with a reduction in non-alcohol related accidents between 1998 and 2006 among 16-to-20 year olds.

Driving/riding after alcohol and marijuana use among young adults: Is residing with family protective?

Objective: Driving while impaired by alcohol or drugs increases the risk of motor vehicle fatalities, the leading cause of death among young adults. The current study documented the prevalence of driving after alcohol and marijuana use in the past 2 weeks as well as the prevalence of riding with a driver who had used each substance during that time frame. We tested whether young adults who lived with family members (i.e., their parents or their children) were less likely to engage in these behaviors.Methods: Participants aged 18–25 who resided in nonmetropolitan areas in the United States (N = 1,131; 55% female, Mage = 22.6) completed an online survey. Multivariate logistic regressions examined alcohol- and marijuana-related driving and riding behaviors adjusting for demographic factors. Interactions tested whether associations varied by gender.Results: In the 2 weeks prior to the survey, 17% of participants drove after drinking alcohol and 21% had ridden with a driver who had been drinking. The prevalence of driving after marijuana use was 11%, and 16% of the sample had ridden with a driver who had been using marijuana. Participants who lived with their parents were less likely to ride with a driver who had been using alcohol or marijuana (adjusted odds ratios [AORs] = 0.71 and 0.55, respectively). Living with parents was also associated negatively with driving after both substances, but these associations were no longer significant when controlling for substance use frequency and driving frequency. Surprisingly, the odds of driving after marijuana use were over 2 times larger for young adults who lived with their children. For women, but not men, residing with children decreased the odds of driving and riding after alcohol use.Conclusions: Living with parents protects against riding after substance use among young adults. Prevention programs should target young adults who live independently or those transitioning away from the parental home. Furthermore, given the higher rates of driving after marijuana use among young adult parents, this group should be educated about the risks associated with this behavior.

For whom didn’t it click? A study of the non-use of seat belts in motor vehicle fatalities in New Zealand

There is an increased risk of death or serious injury for occupants who did not wear a seat belt in a crash. In New Zealand, between 2006 and 2016, the non-use of seat belts accounted for 19-30% of the overall motor vehicle road deaths, and this figure shows no sign of decreasing. It is important to better understand the contextual factors associated with crashes where seat belts are not worn, so that more relevant and effective road safety interventions can be designed and implemented. The aim of this research was to determine the profiles for seat belt non-users who were killed in motor vehicle crashes in New Zealand between 2011 and 2015. An in-depth analysis of 200 fatalities where seat belts were not worn (186 crash cases) was carried out following a Safe System framework, using NZ Police reports. Following this, a Multiple Correspondence Analysis (MCA) developed five profiles of vehicle occupants who were killed in crashes where seat belts were not worn. While the stereotypical ‘young risky’ males were an important group, a range of other people and contexts emerged: ‘driving for work’; ‘elderly and retired’; ‘overseas passengers’; and ‘people driving in rural settings’. This has implications for tailored road safety interventions, as a variety of motivations and influences are likely to be at play, depending on the people involved.

PRECIPITATION AND FATAL MOTOR VEHICLE CRASHES: Continental Analysis with High-Resolution Radar Data.

Precipitation, even at light intensity, contributes a significant risk of fatal motor vehicle crashes across the United States, at nearly all times of day, and in all seasons.

Incidence of fatalities of road traffic accidents associated with alcohol consumption and the use of psychoactive drugs: A 7-year survey (2011-2017).

Driving under the influence of alcohol and/or psychoactive substances increases the risk of severe, even fatal motor vehicle accidents. The aim of this descriptive study was to present the impact of alcohol and/or psychoactive substances on fatal road traffic accidents (RTAs) during the period 2011-2017. For this purpose, the toxicological investigation reports from the Department of Forensic Medicine and Toxicology of the University of Athens were used. In total, 1,841 (32.2%) of the autopsies conducted by the Department of Forensic Medicine and Toxicology of the National and Kapodistrian University of Athens over a 7-year period (2011-2017) were victims of fatal RTAs. Blood and urine samples were collected and analyzed for the presence of alcohol and psychoactive substances. The results were classified according to sex, age, victim (car driver, motorcyclist, pedestrian, or passenger) and the date the accident occurred (day, month and year). In total, 40.7% of the RTA-related fatalities were associated with alcohol consumption, among which 20.3% were car drivers. Of these, 87.3% were male victims. A higher frequency of RTA-related fatalities associated with a blood alcohol concentration (BAC) >110 mg/dl was encountered in younger compared with older age groups. Psychoactive substances were detected in 348 (18.9%) of the victims (cannabis in 46.6% of these, benzodiazepines in 25.9%, opiates in 16.4% and cocaine in 11.1% of these). The percentage of the RTA-related victims that had consumed alcohol in combination with other psychoactive substances was 4.5%. On the whole, the findings of this study suggest that alcohol and psychoactive substances are probably risk factors for RTA-related fatalities.

Legalized Cannabis in Colorado Emergency Departments: A Cautionary Review of Negative Health and Safety Effects.

Cannabis legalization has led to significant health consequences, particularly to patients in emergency departments and hospitals in Colorado. The most concerning include psychosis, suicide, and other substance abuse. Deleterious effects on the brain include decrements in complex decision-making, which may not be reversible with abstinence. Increases in fatal motor vehicle collisions, adverse effects on cardiovascular and pulmonary systems, inadvertent pediatric exposures, cannabis contaminants exposing users to infectious agents, heavy metals, and pesticides, and hash-oil burn injuries in preparation of drug concentrates have been documented. Cannabis dispensary workers (“budtenders”) without medical training are giving medical advice that may be harmful to patients. Cannabis research may offer novel treatment of seizures, spasticity from multiple sclerosis, nausea and vomiting from chemotherapy, chronic pain, improvements in cardiovascular outcomes, and sleep disorders. Progress has been slow due to absent standards for chemical composition of cannabis products and limitations on research imposed by federal classification of cannabis as illegal. Given these factors and the Colorado experience, other states should carefully evaluate whether and how to decriminalize or legalize non-medical cannabis use.

Personality disorders of drivers killed in fatal motor vehicle accidents in Finland during 1990-2011.

To examine the association of personality disorders (PDs) to deaths of drivers in fatal motor vehicle accidents (FMVAs) and analyze gender differences in lifetime psychiatric disorders and medico-legal findings at the time of accident. The study sample consisted of 4810 Finnish drivers killed in FMVAs in Finland between 1990 and 2011. Doctor-diagnosed PD was found in 146 drivers (118 men and 28 women). The information of psychiatric morbidity was obtained from the Finnish Care Register for Health Care. The proportion of deceased drivers with PDs had increased significantly over the study period, particularly among females and those with PD not otherwise specified (NOS). Suicidality and use of medication affecting driving ability were more common among females with PD compared to males with PD. 88% of all deceased drivers with PD had comorbid psychiatric disorders. Our findings indicate that PDs may predispose drivers to FMVAs, particularly females. This study emphasizes the importance of evaluating the fitness-to-drive of subjects with PD and especially comorbid substance use disorders, which may relate to an increased risk of fatal motor accidents.

Restraint use and injury in forward and rear-facing infants and toddlers involved in a fatal motor vehicle crash on a U. S. Roadway

BackgroundUse of appropriate child passenger safety restraints reduces injury in infants, with rear facing restraints favored over forward facing. In 2011, the American Academy of Pediatrics (AAP) began recommending that infants and children under the age of 2 years be restrained in a rear-facing seat installed in the vehicle’s rear seat. This study examines the practice of rear-facing restraints pre- and post-AAP recommendations for children under 2 years.MethodsData from the Fatality Analysis Reporting System (FARS) from 2008 to 2015 were used to examine restraint status and injuries in rear-seated infants and toddlers aged 0 to less than 2 years involved in fatal collisions (n = 4966). Subpopulation analyses were conducted on 1557 children with seat facing direction recorded. Multivariable logistic regression was used to generate odds ratios (OR) with 95% confidence intervals (CI). Covariates considered for inclusion in the multivariable model included passenger characteristics (age, gender, seating position), driver characteristics (age, gender, seat belt status, alcohol status, drug status, previous traffic violations), vehicle characteristics (vehicle type), and crash-level characteristics (day/night, weekday/weekend, rush hour, expressway/surface street, urban/rural).ResultsApproximately 6.7% (330 of 4996) of infants and toddlers were unrestrained with mortality that was approximately triple that of restrained infants (40.0% vs 13.7%, P < 0.0001). In multivariable adjusted models, predictors of an infant being unrestrained included unrestrained driver (OR: 3.17, 95% CI: 2.38–4.21), driver aged less than 20 years (OR: 2.18, 95% CI: 1.42–3.34), driver alcohol use (OR: 2.21, 95% CI: 1.42–3.44), center-seated infant (OR: 1.55, 95% CI: 1.19–2.03) and weekday crash (OR: 1.52, 95% CI: 1.12–2.01). Of all rear-seated children whose restraint status were reported (4966), rear-facing restraint use increased from 5.0% to 23.2% between 2008 and 2015 (P < 0.0001). The odds of rear-facing restraint use increased after introduction of the AAP guideline among infants aged 0 to < 1 year old (OR: 2.12, 95% CI: 1.46–3.10) and among toddlers aged 1 to < 2 years old (OR: 1.97, 95% CI: 1.03–3.79).ConclusionTrends in the use of rear-facing child restraints improved over the timeframe of this study, but remain low despite the introduction of AAP guidelines and the strengthening of child restraint laws.

The Cost of Convenience: Ridehailing and Traffic Fatalities

We examine the effect of the introduction of ridesharing services in U.S. cities on fatal traffic accidents. The arrival of ridesharing is associated with an increase of approximately 3% in the number of motor vehicle fatalities and fatal accidents. This increase is not only for vehicle occupants but also pedestrians. We propose a simple conceptual model to explain the effects of ridesharing’s introduction on accident rates. Consistent with the notion that ridesharing increases congestion and road use, we find that its introduction is associated with an increase in arterial vehicle miles traveled, excess gas consumption, and annual hours of delay in traffic. On the extensive margin, ridesharing’s arrival is also associated with an increase in new car registrations. We find weaker increases in accidents related to drunk driving. These effects are higher in cities with prior higher use of public transportation and carpools, consistent with a substitution effect, and in larger cities and cities with high vehicle ownership. The increase in accidents appears to persist—and even increase—over time. Back-of-the-envelope estimates of the annual cost in human lives range from $5.33 billion to $13.24 billion per year.