Reduce Motor Vehicle Crashes Research Articles

Public Support for a Safe System Approach to Reducing Motor Vehicle Crashes Deaths in the United States

Conventional road safety strategies are yielding diminishing returns. The Safe System approach is based on the premise that human errors will occur on the roadway and that the system should be designed to accommodate these errors, so they do not result in death or serious injury. Elements of the system include the roadway infrastructure, vehicle engineering, and speed management.Political support for U.S. Safe System implementation gained momentum with $5 billion in appropriated funds in the 2021 Bipartisan Infrastructure Law. The purpose of this study was to measure public support for Safe System implementation. We fielded a nationally representative survey of US adults from May 4 to June 10, 2022 (N=2,274). We measured whether respondents considered individual- or systems-oriented approaches as the most effective way to prevent traffic deaths. We also assessed support for various roadway interventions and vehicle safety technologies. Most respondents agreed that system-level changes were the most effective way to prevent traffic deaths. Endorsement for system-level changes was significantly higher among younger age groups. Support for roadway improvements and vehicle safety technologies varied according to the type of intervention that was proposed. Public support for a Safe System approach is high, particularly among younger adults, which suggests that the momentum for the movement can be sustained over the long term.

FEEDBACK trial - A randomised control trial to investigate the effect of personalised feedback and financial incentives on reducing the incidence of road crashes

BackgroundRoad crashes continue to pose a significant threat to global health. Young drivers aged between 18 and 25 are over-represented in road injury and fatality statistics, especially the first six months after obtaining their license. This study is the first multi-centre two-arm parallel-group individually randomised controlled trial (the FEEDBACK Trial) that will examine whether the delivery of personalised driver feedback plus financial incentives is superior to no feedback and no financial incentives in reducing motor vehicle crashes among young drivers (18 to 20 years) during the first year of provisional licensing.MethodsA total of 3,610 young drivers on their provisional licence (P1, the first-year provisional licensing) will participate in the trial over 28 weeks, including a 4-week baseline, 20-week intervention and 4-week post-intervention period. The primary outcome of the study will be police-reported crashes over the 20-week intervention period and the 4-week post-intervention period. Secondary outcomes include driving behaviours such as speeding and harsh braking that contribute to road crashes, which will be attained weekly from mobile telematics delivered to a smartphone app.DiscussionAssuming a positive finding associated with personalised driver feedback and financial incentives in reducing road crashes among young drivers, the study will provide important evidence to support policymakers in introducing the intervention(s) as a key strategy to mitigate the risks associated with the burden of road injury among this vulnerable population.Trial registrationRegistered under the Australian New Zealand Clinical Trials Registry (ANZCTR) - ACTRN12623000387628p on April 17, 2023.

Effect of driving training on car crashes and driving skills in older people: A systematic review and meta-analysis.

The primary aim of this systematic review was to examine the efficacy of driving interventions with regard to a reduction in motor vehicle crashes and improvements in driving skills among older people. The secondary aim was to identify the optimal type (on-road or off-road) and dosage (period, sessions, and duration) of driving interventions for improving driving skills in older people. We searched MEDLINE, EMBASE, PsycINFO, and Scopus of Systematic Reviews for papers published from their inception to December 1, 2020, as well as the reference lists of the included papers. The selected studies were randomized controlled trials examining the effects of driving interventions among community-dwelling older drivers aged 65 years and over. A meta-analysis of two studies (n = 960) showed that driving interventions significantly reduced the number of motor vehicle crashes per person-years. Ten studies (n = 575) were included in the meta-analysis showing that the interventions significantly improved the driving skill scores. Driving skill scores significantly improvedafteron-road training, and in interventions of at least 3 h, 3 sessions, and 3 weeks. Driving interventions significantly improve driving skills and reduce motor vehicle crashes among older drivers aged 65 years and over. On-road training is more efficacious than off-road training and driving interventions of at least 3 h taking place in 3 sessions over a period of 3 weeksmay be required to improve driving skills in older drivers. Geriatr Gerontol Int 2023; 23: 771-778.

The Future of Road Safety: Challenges and Opportunities.

Policy Points Traditional approaches to addressing motor vehicle crashes are yielding diminishing returns. A comprehensive strategy known as the Safe Systems approach shows promise in both advancing safety and equity and reducing motor vehicle crashes. In addition, a range of emerging technologies, enabled by artificial intelligence, such as automated vehicles, impairment detection and telematics hold promise to advance road safety. Ultimately, the transportation system will need to evolve to provide the safe, efficient, and equitable movement of people and goods without reliance on private vehicle ownership, towards encouraging walking, bicycling and the use of public transportation.

Motor Vehicle Crash Deaths - United States and 28 Other High-Income Countries, 2015 and 2019.

Motor vehicle crashes are preventable, yet they continue to be a leading cause of death in the United States. An average of 36,791 crash deaths occurred each year (101 deaths each day) during 2015-2019 in the United States. To measure progress in reducing motor vehicle crash deaths, CDC calculated population-based, distance-based, and vehicle-based death rates in 2015 and 2019, as well as average rates and average percent changes from 2015 to 2019, for the United States and 28 other high-income countries for which data were available. In 2019, the population-based death rate in the United States (11.1 per 100,000 population; 36,355 deaths) was the highest among the 29 high-income countries and was 2.3 times the average rate of the 28 other high-income countries (4.8). The 2019 U.S. distance-based death rate (1.11 per 100 million vehicle miles traveled) was higher than the average rate among 20 other high-income countries (0.92), and the 2019 U.S. vehicle-based death rate (1.21 per 10,000 registered vehicles) was higher than the average rate among 27 other high-income countries (0.78). The population-based death rate in the United States increased 0.1% from 2015 to 2019, whereas the average change among 27 other high-income countries was -10.4%. Widespread implementation of proven strategies and the Safe System approach, which accounts for human error and works to protect everyone on the road, (1) can help reduce motor vehicle crash deaths in the United States.

Re-prioritizing traffic stops to reduce motor vehicle crash outcomes and racial disparities

BackgroundLaw enforcement traffic stops are one of the most common entryways to the US justice system. Conventional frameworks suggest traffic stops promote public safety by reducing dangerous driving practices and non-vehicular crime. Law enforcement agencies have wide latitude in enforcement, including prioritization of stop types: (1) safety (e.g. moving violation) stops, (2) investigatory stops, or (3) economic (regulatory and equipment) stops. In order to prevent traffic crash fatalities and reduce racial disparities, the police department of Fayetteville, North Carolina significantly re-prioritized safety stops.MethodsAnnual traffic stop, motor vehicle crash, and crime data from 2002 to 2016 were combined to examine intervention (2013–2016) effects. Fayetteville was compared against synthetic control agencies built from 8 similar North Carolina agencies by weighted matching on pre-intervention period trends and comparison against post-intervention trends.ResultsOn average over the intervention period as compared to synthetic controls, Fayetteville increased both the number of safety stops + 121% (95% confidence interval + 17%, + 318%) and the relative proportion of safety stops (+ 47%). Traffic crash and injury outcomes were reduced, including traffic fatalities − 28% (− 64%, + 43%), injurious crashes − 23% (− 49%, + 16%), and total crashes − 13% (− 48%, + 21%). Disparity measures were reduced, including Black percent of traffic stops − 7% (− 9%, − 5%) and Black vs. White traffic stop rate ratio − 21% (− 29%, − 13%). In contrast to the Ferguson Effect hypothesis, the relative de-prioritization of investigatory stops was not associated with an increase in non-traffic crime outcomes, which were reduced or unchanged, including index crimes − 10% (− 25%, + 8%) and violent crimes − 2% (− 33%, + 43%). Confidence intervals were estimated using a different technique and, given small samples, may be asymmetrical.ConclusionsThe re-prioritization of traffic stop types by law enforcement agencies may have positive public health consequences both for motor vehicle injury and racial disparity outcomes while having little impact on non-traffic crime.

Would Stronger Seat Belt Laws Reduce Motor Vehicle Crash Deaths?: A Semi-Bayesian Analysis.

For policy questions where substantial empirical background information exists, conventional frequentist policy analysis is hard to justify. Bayesian analysis quantitatively incorporates prior knowledge, but is not often used in applied policy analysis. We combined 2000-2016 data from the Fatal Analysis Reporting System with priors based on past empirical studies and policy documents to study the impact of mandatory seat belt laws on traffic fatalities. We used a Bayesian data augmentation approach to combine information from prior studies with difference-in-differences analyses of recent law changes to provide updated evidence on the impact that upgrading to primary enforcement of seat belt laws has on fatalities. After incorporating the evidence from past studies, we find limited evidence to support the hypothesis that recent policy upgrades affect fatality rates. We estimate that upgrading to primary enforcement reduced fatality rates by 0.37 deaths per billion vehicle miles traveled (95% posterior interval -0.90, 0.16), or a rate ratio of 0.96 (95% posterior interval 0.91, 1.02), and increased the proportion of decedents reported as wearing seat belts by 7 percentage points (95% posterior interval 5, 8), or a risk ratio of 1.18 (95% posterior interval 1.13, 1.24). Bayesian methods can provide credible estimates of future policy impacts, especially for policy questions that occur in dynamic environments, such as traffic safety.

Downwards trends in adolescent risk-taking behaviours in New Zealand: Exploring driving forces for change.

Downwards trends in adolescent risk-taking behaviours in New Zealand: Exploring driving forces for change.

A systematic review of the effectiveness of interventions to reduce motor vehicle crashes and their injuries among the general and working populations.

ABSTRACTObjectiveTo summarize the best available international scientific evidence on the effectiveness of interventions to reduce motor vehicle collisions and their consequences among the working and general populations.MethodsA broad and systematic review was conducted of the literature available in biomedical databases and grey literature. At least two investigators working in parallel performed data extraction, synthesis, and risk of bias analysis.ResultsForty-one studies with low to moderate risk of bias were included. Of these, 18 had an ecological design (time series), 10 were quasi-experimental, one was a population survey, one was a randomized clinical trial, and 11 were systematic reviews.ConclusionsThe interventions that most consistently show a positive effect on incidence, morbidity, and mortality due to motor vehicle collisions are national policies or programs that: regulate, enforce, and penalize driving under the influence of alcohol; improve driving safety and driver conditions; improve road infrastructure with the purpose of preventing collisions; and educate and penalize drivers with a history of road violations.

Primary Enforcement of Mandatory Seat Belt Laws and Motor Vehicle Crash Deaths

Policies that allow directly citing motorists for seat belt non-use (primary enforcement) have been shown to reduce motor vehicle crash deaths relative to secondary enforcement, but the evidence base is dated and does not account for recent improvements in vehicle designs and road safety. The purpose of this study was to test whether recent upgrades to primary enforcement still reduce motor vehicle crash deaths. In 2016, researchers used motor vehicle crash death data from the Fatal Analysis Reporting System for 2000-2014 and calculated rates using both person- and exposure-based denominators. Researchers used a difference-in-differences design to estimate the effect of primary enforcement on death rates, and estimated negative binomial regression models, controlling for age, substance use involvement, fixed state characteristics, secular trends, state median household income, and other state-level traffic safety policies. Models adjusted only for crash characteristics and state-level covariates models showed a protective effect of primary enforcement (rate ratio, 0.88, 95% CI=0.77, 0.98; rate difference, -1.47 deaths per 100,000 population, 95% CI= -2.75, -0.19). After adjustment for fixed state characteristics and secular trends, there was no evidence of an effect of upgrading from secondary to primary enforcement in the whole population (rate ratio, 0.98, 95% CI=0.92, 1.04; rate difference, -0.22, 95% CI= -0.90, 0.46) or for any age group. Upgrading to primary enforcement no longer appears protective for motor vehicle crash death rates.

An evaluation of the effect of Ohio's graduated driver licensing law on motor vehicle crashes and crash outcomes involving drivers 16 to 20 years of age

ABSTRACTObjective: Nationally, motor vehicle crashes are the leading cause of death among youth ages 16 to 20 years. Graduated driver licensing (GDL) laws have been implemented to reduce motor vehicle crashes among teen drivers. Studies have shown decreases in teen crash rates and crash-related fatality rates following enactment of GDL laws. However, GDL laws typically apply to teens only until their 18th birthday; therefore, the effect, if any, that GDL laws have on youth drivers ages 18 to 20 years and whether these programs should be extended to include these older youth warrant further study. The objective of this study was to evaluate the effects of Ohio's 2007 revised GDL law on motor vehicle crashes and crash-related injuries for crashes involving teen drivers ages 16 to 20 years, with a focus on the effects on crashes involving drivers ages 18 to 20 years.Methods: Cross-sectional analysis of motor vehicle crashes involving drivers ages 16 to 20 years in Ohio in the pre-GDL (2004–2006) and post-GDL (2008–2010) periods was performed. Descriptive statistics and population-based crash rates for drivers and occupants ages 16 to 20 years were calculated, as well as rate ratios and 95% confidence intervals (CIs) comparing crashes in the pre-GDL and post-GDL periods.Results: Compared with the pre-GDL period, the post-GDL period was associated with lower crash rates for drivers age 16 years (relative risk [RR] = 0.94; 95% CI, 0.90–0.98), age 17 years (RR = 0.90; 95% CI, 0.88–0.93), age 18 years (RR = 0.95; 95% CI, 0.92–0.97), and ages 16–17 years combined (RR = 0.92; 95% CI, 0.90–0.95). Crash rate was higher for the post-GDL period for drivers age 19 years (RR = 1.04; 95% CI, 1.01–1.07), age 20 years (RR = 1.09; 95% CI, 1.05–1.13), and ages 18–20 years combined (RR = 1.02; 95% CI, 1.00–1.03).Conclusions: Unlike previous studies, this investigation used linked data to evaluate the outcomes of all occupants in crashes involving drivers ages 16–20 years. The post-GDL period was associated with lower crash, injury crash, and fatal crash involvement among drivers and occupants ages 16–17 years but higher overall crash involvement for drivers and occupants ages 19 years, 20 years, and 18–20 years combined. These findings support extending GDL restrictions to novice drivers ages 18 through 20 years to reduce crashes in that group.

The Pattern of Road Traffic Crashes in South East Iran.

Background:In the present study, the epidemiologic aspects of road traffic crashes in South East of Iran are described.Methods:This cross-sectional study included the profile of 2398 motor vehicle crashes recorded in the police office in one Year in South East of Iran. Data collected included: demographics, the type of crash, type of involved vehicle, location of crash and factors contributing to the crash. Descriptive statistics were used for data analysis.Results:Collisions with other vehicles or objects contributed the highest proportion (62.4%) of motor vehicle crashes. Human factors including careless driving, violating traffic laws, speeding, and sleep deprivation/fatigue were the most important causal factors accounting for 90% of road crashes. Data shows that 41% of drivers were not using a seat belt at the time of crash. One- third of the crashes resulted in injury (25%) or death (5%).Conclusions:Reckless driving such as speeding and violation of traffic laws are major risk factors for crashes in the South East of Iran. This highlights the need for education along with traffic law enforcement to reduce motor vehicle crashes in future.

P12 Law Enforcement Involvement and Traffic Safety Effectiveness: Findings from the National Highway Traffic Safety Administration׳s (NHTSA)׳s 2013 Countermeasures That Work

BackgroundRoad traffic injuries are the eighth-leading cause of death globally, and the leading cause of death for people ages 15 to 29 years. Conventional approaches to traffic safety interventions in the United States are based on the three pillars of engineering, enforcement, and education. Law enforcement has gained popularity in traffic safety as a result of high-visibility enforcement campaigns. However, there is mixed evidence for the effectiveness of law enforcement interventions in reducing motor vehicle crashes. This study seeks to evaluate the role of law enforcement in countermeasure effectiveness. MethodsData from the U.S. National Highway Traffic Safety Administration׳s (NHTSA) 2013 Countermeasures That Work was examined. Countermeasures were coded by an expert reviewer to indicate whether the countermeasure required any law enforcement involvement to implement. NHTSA rated each countermeasure on a one- to five-star scale in terms of effectiveness. The NHTSA-rated effectiveness of countermeasures and involvement of law enforcement were cross-tabulated. Spearman׳s rho was calculated to assess the magnitude of the association between law enforcement involvement in a countermeasure and its rated effectiveness. ResultsThere were a total of 116 countermeasures rated. The expert coder indicated that 43% of total countermeasures required law enforcement involvement to implement. Of the countermeasures with law enforcement involvement, 43% were rated 4 or 5 stars. In contrast, 19% of countermeasures that did not involve law enforcement were rated 4 or 5 stars. The effectiveness ratings of programs tended to be higher for programs that had law enforcement involvement than those that did not, Spearman׳s ⍴=.30, p=.002. ConclusionsActing on traffic safety interventions is part of the larger process of building healthy communities while reducing unnecessary morbidity and mortality. This evaluation of the evidence suggests that countermeasures that involve law enforcement tend to be more effective than those that do not. Further analyses will be conducted to examine associations between the type of road safety issue addressed by the countermeasure, the rated effectiveness of the countermeasure, the role of legislation in countermeasure implementation, and possible interactions between legislation and enforcement on program-rated effectiveness.

Effectiveness of an improved road safety policy in Ethiopia: an interrupted time series study.

BackgroundIn recent years, there has been an increasing interest in implementing road safety policy by different low income countries. However; the evidence is scarce on its success in the reduction of crashes, injuries and deaths. This study was conducted to assess whether road crashes, injuries and fatalities was reduced following the road safety regulation introduced as of September 2007 by Oromia Regional State Transport Bureau.MethodsRoutine road traffic accident data for the year 2002-2011were collected from sixteen traffic police offices. Data on average daily vehicle flow was obtained from the Ethiopian Road Authority. Interrupted time series design using segmented linear regression model was applied to estimate the effect of an improved road safety policy.ResultsA total of 4,053 crashes occurred on Addis Ababa - Adama/Hawassa main road. Of these crashes, almost half 46.4% (1,880) were property damage, 29.4% (1,193) were fatal and 24.2% (980) injury crashes, resulting 1,392 fatalities and 1,749 injuries. There were statistically significant reductions in non-injury crashes and deaths. Non-injury crash was reduced by 19% and fatality by 12.4% in the first year of implementing the revised transport safety regulation.ConclusionAlthough revised road safety policy helped in reducing motor vehicle crashes and associated fatalities, the overall incidence rate is still very high. Further action is required to avoid unnecessary loss of lives.

Risk factors for motor vehicle crashes involving civilian drivers and emergency vehicles in use

BackgroundTransportation-related events are the leading cause of death among emergency medical services personnel. Previous research has focused, primarily, on factors associated with emergency vehicle (EV) drivers; however, factors associated with...

The Effectiveness of Cataract Surgery in Reducing Motor Vehicle Crashes: A Whole Population Study Using Linked Data

Purpose: To evaluate the effectiveness of first eye cataract surgery on drivers aged 60 years and over at a population level.Methods: A retrospective before and after comparison of all police reported crashes for patients who had undergone first eye cataract surgery using linked Western Australia data for the period 1997–2006. An economic analysis by the type of crash was performed on the cost savings from cataract surgery for this cohort.Results: Of the 27,827 patients who underwent cataract surgery in one eye only, 1715 patients were involved in 1762 police reported crash events, either 1 year before (n = 941 crashes) or 1 year after (n = 821 crashes) cataract surgery. Results from Poisson generalized estimating equations showed a significant reduction of 12.7% (P = 0.034) in all police reported crashes 1 year after cataract surgery. The corresponding cost savings amounted to $4.3 million.Conclusion: The findings are important for policy development to further improve driving outcomes among older drivers.

Graduated driver licensing for reducing motor vehicle crashes among young drivers

Graduated driver licensing (GDL) has been proposed as a means of reducing crash rates among novice drivers by gradually introducing them to higher risk driving situations. To examine the effectiveness of GDL in reducing crash rates among young drivers. Studies were identified through searching MEDLINE, EMBASE, CINAHL, Healthstar, Web of Science, NTIS Bibliographic Database, TRIS Online, SIGLE, the World Wide Web, conference proceedings, consultation with experts and reference lists in relevant published literature. The searches were conducted from the time of inception to May 2009, and the Cochrane Injuries Group conducted an updated search of the TRANSPORT database in September 2009. Studies were included if: 1) they compared outcomes pre- and post-implementation of a GDL program within the same jurisdiction, 2) comparisons were made between jurisdictions with and without GDL, or 3) both. Studies had to report at least one objective, quantified outcome. Results were not pooled due to substantial heterogeneity. Percentage change was calculated for each year after the intervention, using one year prior to the intervention as baseline. Results were adjusted by internal controls. Analyses were stratified by denominators (population, licensed drivers). Results were calculated for the different crash types and presented for 16 year-olds alone as well as all teenage drivers. We included 34 studies evaluating 21 GDL programs and 2 analyses of >40 US states. GDL programs were implemented in the US (n=16), Canada (n=3), New Zealand (n=1), and Australia (n=1) and varied in their restrictions during the intermediate stage. Based on the Insurance Institute for Highway Safety (IIHS) classification, eleven programs were good, four were fair, five were marginal, one was poor and two could not be assessed. Reductions in crash rates were seen in all jurisdictions and for all crash types. Among 16 year-old drivers, the median decrease in per population adjusted overall crash rates during the first year was 15.5% (range -27 to -8%, five studies). There was a decrease in per population adjusted injury crash rates (median -21%, range -46 to -2%, five studies). Results for all teenage drivers, rates per licensed driver, and rates adjusting for internal controls were generally reduced when comparing within jurisdictions. GDL is effective in reducing crash rates among young drivers, although the magnitude of the effect varies. The conclusions are supported by consistent findings, temporal relationship, and plausibility of the association. Stronger GDL programs (i.e. more restrictions or higher quality based on IIHS classification) appear to result in greater fatality reduction. Future studies should focus on which components and combination of components yield the greatest reductions.

Modelling the performance of pavement marking in cold weather conditions

Inadequate and poorly maintained pavement markings are considered to be one of the largest contributing factors to fatal motor vehicle crashes. As a result, it is essential to apply the appropriate pavement marking material for all weather conditions in order to increase public safety and reduce motor vehicle crashes. Building a strategic plan to renew and re-stripe pavement marking is receiving increasing interest from companies/authorities that manage the pavement marking in order to reach the most cost-efficient management plan of the available pavement marking materials. The objective of this paper is to develop pavement marking performance models that predict the condition of different marking materials under various service conditions including weather, traffic and snow removal plans. The developed models are validated and the results show that the average percent validity varies from 87% to 99%. Marking performance is assessed using a condition rating scale, which numerically ranges from 1 to 5 and linguistically from excellent to critical, respectively. Deterioration curves are developed that assess the condition of the pavement marking based on the developed models. They are expected to benefit academics and practitioners (municipal engineers, consultants, and contractors) to prioritise inspection, stripping, and re-stripping planning for various pavement markings.

Globally we need more comprehensive vision-screening strategies

Cross et al ’s1 recent online article in your esteemed Journal shows that, at present, there is insufficient evidence to support the efficacy of the vision screening test as a...

Effects of Graduated Driver Licensing on Fatalities in 16-Year-Olds

To the Editor.—Motor vehicle crashes are the most common cause of death among youth populations in developed countries in the world.1 Among initiatives developed to reduce motor vehicle crash–related injuries, deaths, and traffic convictions among youth, graduated driver licensing (GDL) laws have demonstrated effectiveness. In particular, a recent retrospective study by Chen et al2 indicated that GDL program components leading to reduced motor vehicle crash fatalities were GDL programs that include age requirements and ≥3 months of waiting before the intermediate stage, nighttime driving restriction, and either ≥30 hours of supervised driving or passenger restriction.Although Chen et al2 provided a valuable contribution to the evidence base, they seem to have overlooked important variables that could affect their outcome (motor vehicle crash fatality), including vehicle miles traveled, vehicle density (number of registered motor vehicles divided by length of roads), speed-limit regulations, alcohol-impaired–driving laws (zero tolerance laws, minimum drinking-age laws), and economic factors (rate of unemployment, real per-capita income, etc). When a relevant variable is omitted from a regression model, the resulting estimators of effect in the final model are biased because they share the variance that would have been attributed to the excluded variable. All factors need to be controlled for in a study of traffic crashes, and results of a study concentrating on a single program (ie, GDL) are possibly misleading. GDL programs cannot be considered to be effective without accounting for confounding in statistical analysis by other laws or programs that also seek to reduce motor vehicle crashes among youth.Driving laws related to alcohol impairment are a particularly important confounder that could also be responsible for reductions in motor vehicle crash injuries and fatalities among youth. Zero tolerance laws, which make it illegal in every state for drivers younger than 21 to drive after any drinking, have significantly contributed to declines in alcohol-related traffic fatalities among people younger than 21. In 1995, the US Congress passed a law that requires states to adopt zero tolerance laws for drivers younger than 21. By 1998, all states had passed laws that made it illegal for any driver younger than 21 to have a positive blood alcohol content (BAC). Voas et al3 used data on all drivers younger than 21 involved in fatal crashes in the United States from 1982 through 1997. Quarterly ratios of BAC-positive to BAC-negative drivers in each of the 50 states were analyzed in a pooled cross-sectional time-series approach. After accounting for differences among the 50 states in various background factors, changes in economic and demographic factors within states over time, and the effects of other related laws, results indicated a significant 24.4% reduction in alcohol-positive drivers younger than 21 who were involved in fatal crashes associated with the zero tolerance laws. Similar results were shown by another systematic review4; therefore, this policy seems to have been significantly effective in reducing fatal crashes involving youth drivers.5,6In addition to zero tolerance laws, other drinking-and-driving laws were also passed in the United States between 1995 and 2005. Many states now revoke or suspend the licenses of drunken-driving offenders who are under the legal age. Characteristics of crashes that take place with alcohol-impaired youth drivers include speeding disproportionately, lack of restraint use, and driving older cars that are in poor repair. Primary and secondary seat belt–enforcement laws, increased speeding restrictions, and improved safety standards for vehicles and highway construction may all help reduce fatal crashes among young drivers. For instance, citizen and community-based advocacy groups have played important prevention roles in areas such as youth drinking and driving and enhancement of youth restraint use.7Further understanding of the effect of these factors in combination with GDL laws should help in the study and implementation of best practices to reduce youth-involved traffic crashes worldwide. Methodologically sound research is needed to evaluate GDL systems and identify which GDL elements produce the greatest crash reductions. To the extent possible, researchers should seek to use appropriate statistical methods that facilitate comparisons across jurisdictions, acknowledging the considerable variation in GDL laws and effects of non-GDL laws and systems across different jurisdictions.