The nature of the alcohol problem in U.S. fatal crashes

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

The effect of motorcyclists' age on injury severities in single-motorcycle crashes with unobserved heterogeneity

INTRODUCTION

Due to the myriad of unique characteristics associated with motorcycle operation, motorcycle safety is a public health concern as complex as it is serious. National crash data suggest motorcyclists are 28 times more likely to be killed when compared to passenger car occupants. In the state of Florida, motorcycle crashes are 1.5 times more likely to result in the death of the rider, placing Florida among the top deadliest states for motorcyclists in the nation. Using police-reported data from 2016, this study addresses the complex and interconnected nature of the many characteristics associated with motorcycle operation by investigating the effect of age on motorcyclists' riding behavior as it relates to injury severity for single-motorcycle crashes in the state of Florida.

METHOD

To account for unobserved heterogeneity in the crash data, mixed logit models with heterogeneity in means and variances were estimated to model three injury severity outcomes (non-visible, severe, and fatal) for three age groups (under 30, 30-49, and 50 and above).

RESULTS

Model results indicate that age affects motorcyclists' safety perception and ability to assess risks, thereby influencing their involvement in risky behaviors. Characteristics unique to motorcycle operation-spatial characteristics, speed, motorcycle type, time of day, helmet usage, alcohol consumption, ejection from motorcycle, passenger presence, endorsement status, and lighting-are further complicated by their dependency on the characteristics of the individual motorcyclist. Age of motorcyclist indicates a relationship between motorcyclists' behavior and perceived safety.

CONCLUSION

The model results indicated that statistically significant parameters constituted different models and they were not equal across the age groups of motorcyclists: aged under 30, aged 30-49, and aged 50 and above. Through advanced econometric modeling, this study fills a gap in the existing literature and assists the safety professionals, motorcycle trainers, policymakers, law enforcement agencies, and roadway designers in developing countermeasures.

Speaking about accidents: the ideology of auto safety

Discourses about traffic accidents are limited by an ideology of automobility that has accompanied increased auto dependence and the hegemony of the automobile over social space. Risk analyses swing back and forth from targeting either human error or technical improvement. While both are important, the attribution of accident causation to systemic factors remains largely ignored. Even in targeting human error, focus is often restricted to causes that are manageable within the existing system, e.g. drunken driving. In reality, there are many human errors and impairments that are implicated in road accidents. Thus, what is significant is that because auto-centered transport depends upon the constant ‘sobriety’ of all traffic participants, impaired driving, walking and cycling are inevitable. Another salient feature of auto-centered transport systems neglected by safety experts is the dominance of ‘hard’ means of mobility. Many argue that larger and heavier vehicles are safer, but the question is for whom and in what traffic and social contexts. In auto-centered transport, some participants, e.g. children and cyclists, who use ‘soft’ means of mobility are particularly disadvantaged. Safety is also differentiated by status (e.g. social class) factors; for example, poorer persons drive poorer vehicles. The lack of attention to systemic factors in safety discourses is congruent with the general culture of individual automobility, which assumes the superiority of auto-centered transport over other, more diversified, structures of movement.

Hazard perception of motorcyclists and car drivers

The current study compares hazard perception (HP) performance of 50 male drivers with and without a motorcycle license in order to generalize results. A video-based HP test, measuring reaction times to traffic scenes, was administered to these two groups of drivers. Participants with a motorcycle license performed better than participants without a motorcycle license. ANOVA indicated that learning improved linearly for participants with a motorcycle license but not for participants without a motorcycle license. No evidence that HP was predicted by age was found. HP scores for drivers who reported previous involvement in an accident were lower than for those who reported not being involved in an accident. The results are discussed in the context of sensitivity and response bias models.

Correcting sample selection in FARS data to estimate seatbelt use

INTRODUCTION

In this paper, we show that FARS data can be a comparable alternative to observational NOPUS data in estimating seat belt use in the United States once we correct for sample selection bias.

RESULTS

Based on assumptions of independence for seatbelt choice, we establish a lower and upper bound for seatbelt usage rates, and find that once we correct for sample selection bias, the seatbelt usage estimates from the corrected FARS emerge at least as a comparable alternative to NOPUS estimates.

IMPACT ON INDUSTRY

This implies that researchers can use corrected FARS to complement NOPUS, thus being able to utilize the rich cross-sectional details available in FARS data to analyze various relevant research questions.

[Drinking-and-driving prevalence in Belo Horizonte, Minas Gerais State, Brazil]

Problems resulting from alcohol consumption by drivers have been studied worldwide, and epidemiological research points to high injury and death rates related to drinking-and-driving. However, equivalent data are limited in Brazil. In this study, 913 drivers were stopped on public roads with heavy traffic and high concentrations of bars, restaurants, and nightclubs in Belo Horizonte, Minas Gerais State, and asked to answer a questionnaire and submit to an active breathalyzer test. The study was done in December 2005 and December 2006. The study adopted the internationally accepted sobriety checkpoint method. In the sample, 38.0% of drivers showed some trace of alcohol in their exhaled air, and 19.6% were at or above the legal limit (0.6 g/l). These figures were five times those found in similar surveys in other countries. The findings suggest a critical drinking-and-driving problem in Belo Horizonte (and probably elsewhere in Brazil) and the need for on-going research, the development of specific public policies to deal with the problem, and effective enforcement of the existing law.

Civil liability, criminal law, and other policies and alcohol-related motor vehicle fatalities in the United States: 1984-1995

This study examines the associations between alcohol policies and motor vehicle fatality rates from 1984 to 1995 in the United States. State policies and state characteristics variables were merged with motor vehicle fatality rates over an 11 year period and analyzed using minimum logit chi-square method and fixed effects to create a quasi time-series analysis. Laws allowing individuals to sue bars for the drunken behavior of their patrons were the policies most strongly associated with lower minor and adult fatality rates. The mandatory first offense fine was associated with lower minor fatality rates but not adult fatality rates, while minor and adult rates fell after administrative per se license suspension and anti-consumption laws for all vehicle occupants. Many other public policies evaluated were not associated with lower fatality rates.

Evaluation design for a community prevention trial. An environmental approach to reduce alcohol-involved trauma

The Community Prevention Trial was 5-year effort to reduce alcohol-involved injuries and death through a comprehensive program of community awareness and policy activities. The three experimental communities were of approximately 100,000 population each (one in Northern California, one in Southern California, and one in South Carolina). Matched comparison communities were used for each experimental community. This article describes the evaluation approach used in a program that sought to change environmental factors not a specific population or target group. This approach demanded unique evaluation approaches for determining overall community aggregate effects, that is, distal outcomes, as well as changes in key mediating variables, that is, process effects. The problem of trending and lagged effects of community prevention programs are discussed.

Alcohol-related predictors of adolescent driving: gender differences in crashes and offenses

Demographic and alcohol-related data collected from eight-grade students (age 13 years) were used in logistic regression to predict subsequent first-year driving crashes and offenses (age 17 years). For young men's crashes and offenses, good-fitting models used living situation (both parents or not), parents' attitude about teen drinking (negative or neutral), and the interaction term. Young men who lived with both parents and reported negative parental attitudes regarding teen drinking were less likely to have crashes and offenses. For young women's crashes, a good-fitting model included friends' involvement with alcohol. Young women who reported that their friends were not involved with alcohol were least likely to have crashes. No model predicting young women's offenses emerged.

Statewide substance abuse prevention planning

The State of Rhode Island contracted with the authors to prepare a statewide, comprehensive substance abuse prevention plan. The literature review revealed a lack of research on statewide planning for prevention services. To obtain data for Rhode Island's plan, the authors conducted a family of studies including synthetic estimation, key informant interviews, a telephone survey of agency directors, program budget analysis, construction of a statistical index for estimating the optimal geographic allocation of prevention dollars, and a review of General Laws regarding tobacco, alcohol, and other drugs. Their recommendations include the increased funding and coordination of prevention services, allocating services according to need rather than population size, greater use of social policy as a prevention tool, and a shift in primary prevention programming from senior high to lower grades and in program emphasis from information-education to psychosocial programs.

The relationship of the retail availability of alcohol and alcohol sales to alcohol-related traffic crashes

The research literature on the relationship of alcohol consumption to motor vehicle crash risk clearly implicates the importance of minimizing the use of alcohol in conjunction with the operation of motor vehicles. However, there has been relatively little documentation of the direct impact of changes in beverage-specific alcohol sales on the most common surrogate for alcohol-involved traffic crashes, single-vehicle nighttime fatalities. Similarly, there have been few studies of the relationship between the physical availability of alcohol and fatal crash rates which have concurrently controlled for differences in alcohol sales. Indeed, the possibility that reduced availability might lead to increases rather than decreases in fatal crashes (due to increased driving after drinking) has not been adequately tested. This paper presents a series of analyses of time-series cross-sectional data from 38 states over 12 years to evaluate the impact of changes in alcohol sales and the physical availability of alcohol upon single-vehicle nighttime fatal crashes. The results of the study showed, first, that independent of a number of economic and demographic covariates, rates of single-vehicle nighttime fatal crashes were most strongly related to sales of beer and less so to sales of spirits and wine. Second, net of beverage-specific alcohol sales, the physical availability of alcohol was not related to measurable changes in fatal crash rates. Thus, reductions in availability intended to reduce alcohol sales and problems would not appear to increase traffic-related crashes through increased driving exposure.

The risk of dying in alcohol-related automobile crashes among habitual drunk drivers

BACKGROUND

Reports suggest that people who drive while intoxicated by alcohol may do so repeatedly. We hypothesized that persons arrested for driving while impaired might be at increased risk for death in an alcohol-related motor vehicle crash. To evaluate this possibility, we studied the deaths of drivers in alcohol-related motor vehicle accidents in North Carolina over a 10-year period.

METHODS

We compared drivers who died in motor vehicle crashes from 1980 through 1989 and who had blood alcohol concentrations of at least 20 mg per deciliter (4.3 mmol per liter), referred to as the case drivers, with those who died in crashes but had blood alcohol concentrations below 20 mg per deciliter, referred to as the control drivers. We identified case drivers and control drivers through the state Medical Examiner System. We then searched North Carolina driver-history files for the five years before each death to identify arrests for driving while impaired.

RESULTS

We linked a total of 1646 case drivers and 1474 control drivers to their driver-history files. Case drivers were more likely than control drivers to have been arrested for driving while impaired (26 percent vs. 3 percent). After we controlled for potential confounding variables, case drivers 21 to 34 years of age were 4.3 times more likely (95 percent confidence interval, 2.7 to 6.8) than control drivers to have been arrested for driving while impaired; case drivers 35 years of age or older were 11.7 times more likely (95 percent confidence interval, 6.8 to 20.1). The strength of the association appeared to increase with the number of prior arrests. Case drivers were also more likely than the general population of currently licensed drivers to have been arrested.

CONCLUSIONS

Arrests for driving while impaired substantially increase the risk of eventual death in an alcohol-related crash. Aggressive intervention in the cases of people arrested for driving while impaired may decrease the likelihood of a future fatal alcohol-related crash.

Etiology of drinking and driving among adolescents: implications for primary prevention

A prospective study was conducted to investigate what factors are predictive of self-reported drinking and driving (DD) among adolescents. The study employs a theoretical framework taken from Problem Behavior Theory; environmental, personality, and behavioral factors are explored for their predictability of DD. A cohort of 1482 high school students completed a written survey in spring of 1986 and again in fall of 1986. The findings confirm that Problem Behavior Theory provides a useful theoretical framework with which to identify etiological factors predictive of DD among adolescents. Identified personality, perceived environmental, behavioral, and demographic factors accounted for approximately 50% of the reported variance in DD at baseline. The same factors accounted for approximately 40% percent of the variance in follow-up DD and were predictive both among the students who did not drink and drive at baseline (incidence cases), and among those students who did drink and drive at baseline (continuation versus discontinuation of the behavior). Based on these etiological data, we recommend that school-based, peer-led educational prevention programs be designed to reach young adolescents prior to the age at which a driver's license is obtained. We further recommend that the programs be broad-based and consider DD within the larger context of drinking and driving related behaviors and traffic safety in general.

Policy alternatives for alcohol-impaired driving

This article summarizes current scientific evidence about the impact of public policy measures on alcohol-related motor vehicle crashes. The public policy measures considered are (1) minimum drinking age laws, (2) taxation of alcoholic beverages, (3) drinking and driving laws, (4) laws and regulations governing the physical availability of alcoholic beverages, and (5) server intervention programs. It is concluded that certain public policy measures reduce alcohol-related crashes. These measures include higher taxes on alcoholic beverages and at least some laws and regulations governing the physical availability of alcohol (as well as the minimum drinking age). The article suggests that strengthening drinking and driving laws without also adopting these other measures may have less than optimum (and possibly disappointing) effects.