Trends and disparities in alcohol-DWI license suspensions by suspension duration, North Carolina, 2007-2016.

PURPOSE: To examine trends and potential disparities in North Carolina (NC) driving while impaired by alcohol (alcohol-DWI) license suspensions from 2007-2016. Specific objectives included: 1) examining personal (e.g., race/ethnicity) and contextual (e.g., residential segregation) characteristics of alcohol-DWI license suspensions by suspension duration; and 2) examining trends in annual suspension rates by race/ethnicity, sex, and duration. METHODS: We linked NC administrative licensing and county-level survey data from several sources from 2007-2016. Suspensions were categorized by duration: 1 to <4 years and 4 years or longer (proxies for initial and repeat suspensions, respectively). We calculated counts, percentages, and suspensions rates (per 1,000 person-years) with 95% confidence intervals, examined trends in annual suspension rates by race/ethnicity, sex, and suspension duration. RESULTS: We identified 220,471 initial and 41,526 repeat license suspensions. Rates among males were three times that of females. 21-24-year-old (rates: 6.9 per 1,000 person-years for initial; 1.5 for repeat) and Black (4.1 for initial; 1.0 for repeat) individuals had the highest suspension rates. We observed decreases in annual initial and repeat suspension rates among males, but only in repeat suspensions for females during the study period. A substantial decrease in annual initial suspension rates was observed among Hispanic individuals relative to other racial/ethnic groups, while annual repeat suspension rates exhibited large decreases for most racial/ethnic groups. The highest overall suspension rates occurred in counties with higher proportions of the population without health insurance and with the highest levels of Black/White residential segregation. CONCLUSIONS: Potential disparities by race/ethnicity and sex existed by alcohol-DWI license suspension duration (i.e., initial vs. repeat suspensions) in NC. Contextual characteristics associated with suspensions, including a high degree of residential segregation, may provide indications of underlying structures and mechanisms driving potential disparities in alcohol-DWI outcomes.

How do perceptions of procedural justice, police legitimacy, and legitimacy of laws influence intentions to drug drive?

INTRODUCTION: There is a need for improved drug driving enforcement to promote greater driver compliance with drug driving laws. In Australia, Roadside Drug Testing (RDT) suffers from operational challenges that undermine its effectiveness in reducing drug driving. OBJECTIVE: To identify potential improvements to RDT, this study investigated the extent to which drivers perceive RDT to be procedurally just and that the policing of drug driving and the associated laws are legitimate. These perceptions were then compared with those applying to Random Breath Testing (RBT) and examined in relation to their respective influence on intentions to drug and drink drive in the future. METHOD: A sample of 1,483 licensed drivers from three Australian states completed an online survey. RESULTS: Those participants who reported engaging in drug driving perceived RDT to be less procedurally just than non-drug drivers. Similarly, drug drivers perceived the police and associated drug driving laws to be less legitimate than non-drug drivers. Furthermore, drug drivers who had been tested at an RDT operation in the past perceived RDT to be less procedurally just and considered drug driving policing and laws to be less legitimate, compared with the corresponding perceptions of drink drivers who had been tested at an RBT operation. A regression analysis indicated that stronger intentions to drug drive in the future were associated with lower perceptions of police legitimacy and the legitimacy of drug driving laws, but not with the elements of procedural justice. However, follow-up analyses indicated that the influence of procedural justice on intentions was mediated by the two legitimacy variables, thus weakening its direct impact on intentions. PRACTICAL APPLICATIONS: The results highlight the need for road safety authorities to enhance the perceived legitimacy of drug driving enforcement and associated laws. Changes to current police practices and/or drug-driving laws may also be needed to enhance the effectiveness of RDT.

Cannabis policy bundles and traffic fatalities in the American States over time.

BACKGROUND AND AIM: Since 1996, 38 US states have legalized access to cannabis (medical and/or adult-use recreational). We aimed to estimate the effect of three dimensions of state cannabis policy design - pharmaceutical, permissive and fiscal - on levels of overall, alcohol-impaired, occupant, light truck and pedestrian fatality rates. DESIGN AND SETTING: Observational study of US states' overall, alcohol-impaired, occupant, light truck and pedestrian fatalities between 1994 and 2020. CASES: The unit of analysis was at the state level, consisting of 50 states and 27 years of time series data, resulting in a total of 1350 state-year observations. MEASUREMENTS: Fatality rates associated with alcohol-impaired, pedestrian, total occupant, passenger car and light truck fatality rates were obtained from the Fatality Analysis Reporting System of the National Highway Traffic Safety Administration and normalized per 10 billion vehicle miles traveled. State cannabis policies are measured in three bundles (scales): pharmaceutical, permissive and fiscal. FINDINGS: The pharmaceutical bundle was associated with increases in all fatality rates [ß = 0.145; 95% confidence interval (CI) = 0.116-0.173; P < 0.000]. The permissive bundle was associated with lower overall fatality rates (ß = -0.319; 95% CI = -0.361 to -0.277; P < 0.000). The fiscal bundle was generally associated with higher fatality rates (ß = 0.062; 95% CI = 0.043-0.081; P < 0.000), occupant (ß = 0.070; 95% CI = 0.042-0.098; P < 0.000), light trucks (ß = 0.049; 95% CI = 0.026-0.072; P < 0.000). CONCLUSIONS: US state cannabis regulations influence traffic safety. Greater permissiveness in US state cannabis regulations does not appear to correlate with traffic fatality rate increases, but greater medicalization and fiscal operation does.

Implementation of the new acts on driving under the influence of alcohol and clinical outcomes for patients severely injured in road traffic crashes.

OBJECTIVE: Driving under the influence (DUI) of alcohol is a major risk factor for fatal road traffic injuries (RTIs) worldwide. This study aimed to investigate the relationship between the implementation of new acts on DUI of alcohol and the clinical outcomes of patients with severe RTIs in Korea. METHODS: This is a community-based cross-sectional study using a nationwide severe trauma registry in Korea. In 2018, 2 acts with the Yoon Chang-Ho Act (Yoon's Act) were passed to strengthen the punishment for drunk driving fatal RTIs (first Yoon's act) and lower the blood alcohol concentration limit to restrict driver's licenses (second Yoon's act). The first Yoon's act was implemented on December 18, 2018, and the second Yoon's act was implemented on June 25, 2019. The study periods were categorized as pre-Act-1, pre-Act-2, Act-1, and Act-2 according to the application of Yoon's Act, and the study outcome was in-hospital mortality. Multivariable logistic regression analysis was conducted to estimate the relationship of the new acts and in-hospital mortality. RESULTS: Among a total of 20,376 patients with severe RTIs and 7,928 patients (drivers) with RTIs (hereafter drivers), the in-hospital mortality rates were 20.8% and 17.0%, and alcohol-related RTIs accounted for 9.7% and 8.1%, respectively. Severe RTIs tended to increase with each period (25.5 cases/day, 24.5 cases/day, 26.8 cases/day, and 30.4 cases/day, P for trend <.01). In-hospital mortality significantly decreased during the Act-2 period compared to the pre-Act-2 period for all patients with severe RTIs (adjusted odds ratio = 0.54, 95% confidence interval 0.43-0.67) and drivers with RTIs (adjusted odds ratio = 0.50, 95% confidence interval 0.34-0.73). CONCLUSIONS: Implementation of the new acts on DUI of alcohol was associated with lower odds for in-hospital mortality for patients with severe RTIs. Further studies are needed to evaluate the long-term impact of the new acts on reducing alcohol-related RTIs.

State Driving Under the Influence of Drugs Laws.

Drug-impaired driving is a growing problem in the U.S. States regulate drug-impaired driving in different ways. Some do not name specific drugs or amounts. Others do identify specific drugs and may regulate cannabis separately. We provide up-to-date information about these state laws.

Drinker driver flyer diver.

Blood alcohol concentrations above defined levels are detrimental to cognitive performance. Empirical and published evidence suggest that nitrogen narcosis is analogous to alcohol intoxication with both impairing prefrontal cortex function. Nitrogen narcosis is also known to have been a factor in fatal accidents. To examine the effects of nitrogen narcosis, a recent publication used the Iowa Gambling Task tool, to simulate dynamic real-life risky decision-making behaviour. If the reported outcomes are corroborated in larger rigorously designed studies it is likely to provide further evidence that divers may well experience the negative effects of a 'narcotic agent', even at relatively shallow depths. These deleterious effects may occur regardless of diving experience, aptitude or professional status. In 1872, English law made it an offence to be 'drunk' whilst in charge of horses, carriages, cattle and steam engines. Understanding the danger was easy, establishing who is 'drunk' in the eyes of the court required a legal definition. Driving above a 'legal limit' for alcohol was made illegal in the United Kingdom in 1967. The limit was set at 80 milligrams of alcohol per 100 millilitres of blood. It took just short of one hundred years to get from first introducing a restriction to specific activities, whilst under the influence of alcohol, to having a clear and well-defined enforceable law. The question surely is whether our modern society will tolerate another century before legally defining safe parameters for nitrogen narcosis?

Road safety implications of the partial legalisation of cannabis in Germany: protocol for a quasi-experimental study.

INTRODUCTION: Germany is reforming its legal approach to cannabis, allowing the possession and cultivation of cannabis for recreational purposes. The objective of this study is to investigate the impact of the policy reform on (1) The prevalence of cannabis use in the general population and (2) Driving under the influence of cannabis (DUIC) among regular users. METHODS AND ANALYSIS: A quasi-experimental research design will be employed, with repeated cross-sectional surveys on self-reported DUIC and cannabis use conducted at three measurement points in Germany (intervention group) and Austria (control group) over a 2-year observation period (2023-2025). Data will be collected from approximately 50 000 individuals aged between 18 years and 64 years. To minimise reporting biases in the measurement of DUIC, we will use direct and indirect assessments via crosswise model and motor vehicle accident data from official statistics. In a difference-in-difference framework, regression analyses and interrupted time series analysis will be carried out for hypothesis testing. ETHICS AND DISSEMINATION: Participants will be informed about voluntary participation, data protection laws and the option to delete data on request. Ethical approval was obtained from the Local Psychological Ethics Committee of the Centre for Psychosocial Medicine in Hamburg, Germany (reference number: 0686). Findings will be disseminated through scientific networks and will be key for a comprehensive evaluation of the cannabis law reform. The findings will facilitate the design and implementation of road safety measures.

Drink then drive away: The effects of lowering the blood alcohol concentration in Utah.

In March of 2017 Utah announced its intent to lower the legal blood alcohol content (BAC) for driving from 0.08 to 0.05 g/dL. However, this change did not take effect until 2019. We employ a difference-in- differences strategy on Utah counties using neighboring states as controls to test whether this policy change significantly affected the number of traffic accidents or the severity of those accidents. Results show the policy appears to temporarily decrease the total number of accidents, limited primarily to property damage- only accidents. We believe these results may be partially explained by drivers who, after the policy is enacted, avoid reporting property damage-only accidents if possible. Using insurance claims data, we show there is no corresponding fall in insurance claims or payouts suggesting that the fall in total accidents likely comes from under-reporting.

Do tougher drinking policies affect men's smoking behavior - Evidence from China.

In 2011, China implemented tougher driving-under-the-influence laws, which criminalized driving under the influence of alcohol for the first time and increased penalties. This paper provides the first comprehensive analysis of the effects of stricter drinking policies on men's smoking behavior by using data from the 2010 and 2012 waves of the China Family Panel Studies. The results show that stricter drinking policies reduced smoking initiation and the number of cigarettes smoked per day among men by reducing the frequency and quantity of alcohol consumption. Heterogeneity analyses show that the impact of the policy is more pronounced not only for men aged 41-55, but also for men who have higher educational qualifications, who are employed, or who are not members of the Communist Party.

Delays in blood collection and drug toxicology results among crash-involved drivers arrested for impaired driving.

OBJECTIVE: The concentration of drugs in a driver's system can change between an impaired driving arrest or crash and the collection of a biological specimen for drug testing. Accordingly, delays in specimen collection can result in the loss of critical information that has the potential to affect impaired driving prosecution. The objectives of the study were: (1) to identify factors that influence the time between impaired-driving violations and specimen collections (time-to-collection) among crash-involved drivers, and (2) to consider how such delays affect measured concentrations of drugs, particularly with respect to common drug per se limits. METHOD: Study data included blood toxicology results and crash-related information from 8,923 drivers who were involved in crashes and arrested for impaired driving in Wisconsin between 2019 and 2021. Analyses examined how crash timing and severity influenced time-to-collection and the effects of delays in specimen collection on blood alcohol concentrations (BACs) and blood delta-9-tetrahydrocannabinol (THC) concentrations. RESULTS: The mean time-to-collection for the entire sample was 1.80 h. Crash severity had a significant effect on time-to-collection with crashes involving a fatality having the longest duration (M = 2.35 h) followed by injury crashes (M = 2.06 h) and noninjury crashes (M = 1.69 h). Time of day also affected time-to-collection; late night and early morning hours were associated with shorter durations. Both BAC (r = -0.11) and blood THC concentrations (r = -0.16) were significantly negatively correlated with time-to-collection. CONCLUSIONS: Crash severity and the time of day at which a crash occurs can result in delays in the collection of blood specimens after impaired driving arrests. Because drugs often continue to be metabolized and eliminated between arrest and biological specimen collection, measured concentrations may not represent the concentrations of drugs that were present at the time of driving. This has the potential to affect drug-impaired driving prosecution, particularly in jurisdictions whose laws specify per se impairment thresholds.

Measurement uncertainty of ethyl alcohol concentration in the exhaled breath of drivers and determination of sobriety at the time of incident. / Niepewnosc pomiaru stezenia alkoholu etylowego w powietrzu wydychanym kierowców oraz ustalenia stanu trzezwosci w chwili zdarzenia.

The aim of the study was to determine the components of measurement uncertainty in the concentration of alcohol in exhaled breath and to determine the state of sobriety at the time of incident. Based on the literature review and the authors' experience in providing opinions for law enforcement and the judiciary, the influence of various factors on the final interpretation of sobriety state is described on the basis of measurement uncertainty of breath analyzers, uncertainty of retrospective and prospective calculations, and uncertainty related to the conversion of alcohol concentrations detected during breath and blood tests. The paper pays particular attention to interpreting the concentrations of ethanol in exhaled breath close to the legal limits of the state of sobriety and the state after alcohol use, or the state after alcohol use and the state of insobriety. Analyzing the results of an exhaled breath test concerning concentrations close to the values of 0.1 mg/dm3 and 0.25 mg/dm3, it is necessary to take into account the factors affecting the measurements obtained, including the measurement uncertainty of the determination of alcohol in exhaled breath, the processes of absorption, distribution and metabolism of ethyl alcohol, and the possibility of the presence of alcohol lingering in the oral cavity. The incorrect execution of measurements of the tested person's alcohol concentration is also a problematic issue. When determining sobriety state by means of retrospective and prospective calculations, it is important to remember that the uncertainty of the result is affected by a number of factors and depends, among other things, on the information provided by the suspect. Hence, the expert should draw conclusions particularly cautiously and any overestimation or underestimation of the components of uncertainty can lead to erroneous conclusions. Awareness of the uncertainties inherent in the results of a sobriety test or alcohol calculation allows for meaningful interpretation of test results and determination of the sobriety state of the person tested.

Concentration units used to report blood- and breath-alcohol concentration for legal purposes differ between countries which is important to consider when blood/breath ratios of alcohol are compared and contrasted.

This technical note reviews the plethora of concentration units used to report blood-alcohol concentration (BAC) and breath-alcohol concentrations (BrAC) for legal purposes in different countries. The choice of units sometimes causes confusion when scientific papers originating from a certain country might be introduced into evidence via expert testimony, such as when alcohol-related crimes are prosecuted. The concentration units are also important to consider when blood/breath ratios (BBRs) of alcohol are calculated and compared between countries. Statutory BAC limits for driving in most nations are reported in mass/volume (m/v) units, such as g/100 mL (g%) in the United States, mg/100 mL (mg%) in the United Kingdom and Republic of Ireland, or g/L (mg/mL) in many EU nations. By contrast, Germany and the Nordic countries report BAC as mass/mass (m/m) units, hence g/kg or mg/g, which are ~5.5% lower than m/v units, because whole blood has an average density of 1.055 g/mL. There are historical reasons for reporting BAC in mass/mass units because the aliquots of blood analyzed were measured by weight rather than volume. The difference between m/m and m/v is also important in postmortem toxicology, such as when distribution ratios of ethanol between blood and other biological specimens, such as urine, vitreous humor, and cerebrospinal fluid, are reported.

How do drunk-driving events escalate into drunk-driving crashes? An empirical analysis of Beijing from a spatiotemporal perspective.

Drunk-driving events often escalate into drunk-driving crashes, however, the contributing factors of this progression remain elusive. To mitigate the likelihood of crashes stemming from drunk-driving events, this paper introduces the notion of 'the severity of drunk-driving event' and examines the complex relationship between the severity and its contributing factors, considering spatiotemporal heterogeneity. The study utilizes a Geographically and Temporally Weighted Binary Logistic Regression (GTWBLR) model to conduct spatiotemporal analysis based on police-reported drunk-driving events in Beijing, China. The results show that most factors passed the non-stationary test, indicating their effects on the severity of drunk-driving event vary significantly across different spatial and temporal domains. Notably, during non-workday, drunk-driving events in northeast of Beijing are more likely to escalate into crashes. Furthermore, severe weather during winter in the northwest of Beijing is associated with high risk of drunk-driving crashes. Based on these insights, the authorities can strengthen drunk-driving checks in the northeast region of Beijing, particularly during non-workdays. And it is crucial to promptly clear accumulated snow on the roads during severe winter weather to improve road safety. These insights and recommendations are highly valuable for reducing the risk of drunk-driving crashes.

Overview of road traffic injuries among migrant workers in Guangzhou, China, from 2017 to 2021.

INTRODUCTION: There are many migrant workers in China's first-tier cities, but little is known about road safety. This paper systematically analysed road traffic injuries and risk factors among migrant workers in Guangzhou, China. METHODS: Road traffic crash data from 2017 to 2021 were obtained from the Guangzhou Public Security Traffic Management Integrated System. We plotted the crash network of road users in road traffic crashes and used logistic regression to analyse the risk factors for migrant workers of motorcycle and four-wheeled vehicle crashes. Moreover, the roles of migrant workers and control individuals as perpetrators in road traffic crashes were also analysed. RESULTS: Between 2017 and 2021, 76% of road traffic injuries were migrant workers in Guangzhou. Migrant workers who were motorcyclist drivers most commonly experienced road traffic injuries. Crashes between motorcyclists and car occupants were the most common. The illegal behaviours of migrant worker motorcyclists were closely related to casualties, with driving without a licence only and driving without a licence and drunk driving accounting for the greatest number. Migrant workers were responsible for many injuries of other road users. Motorcycle drivers have a higher proportion of drunk driving. DISCUSSION: Migrant workers play an important role in road traffic safety. They were both the leading source of road traffic injuries and the main perpetrators of road traffic crashes. Measures such as strict requirements for migrant workers to drive motorcycles with licences, prohibit drunk driving, greater publicity of road safety regulations, and combining compulsory education with punishment for illegal behaviours.

Roadside Drug Testing Approaches.

The purpose of this review is to present an overview of roadside drug testing, driving enforcement, and drunk/drug driving detection around the world. Drunk and drug driving is a severe problem, not only in the UAE, but also around the world. This has important implications for road safety as drunk or drug driving may increase the chances of a driver's involvement in a road crash when compared to a drug-free driver. Recently, due to increases in drug-impaired drivers' crash involvement, many mobile roadside drug testing devices have been introduced to the market. These devices use oral fluid, urine or blood matrices. These are on-the-spot tests, which are easy to use and are applied by law enforcement agencies and the public. Law enforcement agencies most commonly use oral fluid to detect the presence of illicit drugs in drivers. This review discusses all the available devices in the market used by the authorities. It also describes the type of drugs widely abused by drivers along with behavioral testing methods. The different types of matrices used for roadside drug testing are also evaluated. Sample collection, storage, and pre-treatment methods are discussed, followed by the confirmatory analysis of positive samples. This article will significantly help law enforcement agencies compare and evaluate all the reliable roadside testing devices and new emerging confirmatory devices available to them in the market. This will help them make an informed decision on which device to adapt to their individual needs.

Nigerian law enforcement agents' knowledge and enforcement of drink-drive law.

OBJECTIVE: To understand how knowledgeable and equipped the law enforcement agents in Nigeria are to enforce the drink-drive law. METHOD: We conducted a descriptive cross-sectional study of Law Enforcement Agents in four Nigerian states selected by convenient sampling. The study utilized a pre-tested questionnaire designed to obtain subjects' demographic data, elicit their knowledge about drink-drive law, and understand how equipped the subjects are. A team member walked respondents through the questions to ensure comprehension and accuracy with completion of the questions. RESULT: 496 law enforcement agents were studied. They were 414(83.5%) male and 82(16.5%) females, mostly aged 21-40 years (64.3%). Close to half (48.2%) were police officers, while 35.7% were officers in the Federal Road Safety Corp (FRSC). 45% of respondents had secondary/high school education, while 39.5% had bachelor's degree; with a significant majority in the FRSC. 269(54.2%) respondents had convicted a road user of drunk driving/riding on the basis of subjective assessment. The use of breathalyzers and awareness of permissible Blood Alcohol Concentration (BAC)/Breath Alcohol Concentration (BrAC), was reported by a few respondents (5%), mostly FRSC officers, and others with relatively higher educational attainment. The majority were ignorant of the approved BAC limit in Nigeria (0.05 g/100 dl) and objective methods of assessing breath alcohol concentrations. CONCLUSION: In Nigeria, there is a huge knowledge gap on the drink-drive law and the acceptable penalties for offenders in Nigeria among law enforcement agents. The law enforcement agents lack equipment for objectively detecting drunk driving among road users. Our findings call for an urgent intervention in the training and practice of law enforcement agents if the prevalence of RTC arising from drunk driving will be reduced in Nigeria.

An examination of how alcohol enforcement strategies by sheriff and police agencies are associated with alcohol-impaired-driving fatal traffic crashes.

Objective: Over 10,000 people die in alcohol-impaired-driving traffic crashes every year in the U.S. Approximately half of alcohol-impaired drivers report their last drink was at a bar or restaurant, and most bars and restaurants serve alcohol to patrons who are already intoxicated, known as overservice. Law enforcement agencies use various strategies to address alcohol-impaired driving and overservice but research on the effectiveness of these strategies is limited. Our objective was to assess whether law enforcement efforts focusing on alcohol-impaired driving and alcohol overservice were associated with alcohol-impaired-driving fatal traffic crashes.Methods: We conducted a survey of police and sheriff agencies in 1,082 communities across the U.S. in 2010 regarding their alcohol enforcement practices. We assessed whether the agency conducted: (1) alcohol overservice enforcement and (2) alcohol-impaired driving enforcement (sobriety checkpoints, saturation patrols, open container, overall alcohol-impaired driving enforcement). From the Fatality Analysis Reporting System (2009-2013), we obtained counts of alcohol-impaired-driving fatal traffic crashes (at least one driver had blood alcohol content ≥ 0.08) within the agency's jurisdiction boundary and within a 10-mile buffer. Using multi-level regression, we assessed whether each enforcement type was associated with alcohol-impaired-driving fatal crashes (per 100,000 population). For both the jurisdiction boundary and 10-mile buffer, we ran stratified models based on community/agency type: (1) small town/rural police; (2) urban/suburban police and (3) sheriffs.Results: In jurisdiction boundary models, urban/suburban communities where police conducted overservice enforcement (compared to those that did not) had fewer alcohol-impaired-driving fatal crashes (5.0 vs. 6.6; p = 0.01). For the 10-mile buffer, small town/rural communities where police agencies conducted overservice enforcement (compared to those that did not) had fewer alcohol-impaired-driving fatal crashes (16.9 vs. 21.2; p = 0.01); we found similar results for small town/rural communities where police used saturation patrols (18.7 vs. 22.1; p = 0.05) and had overall high alcohol-impaired driving enforcement (18.7 vs. 22.1; p = 0.05). The direction and the size of the effects for other types of enforcement and agencies were similar, but not statistically significant.Conclusions: Alcohol enforcement strategies among police agencies in small town/rural communities may be particularly effective in reducing alcohol-impaired fatal traffic crashes. Results varied by enforcement, agency and community type.

Association of Rideshare Use With Alcohol-Associated Motor Vehicle Crash Trauma.

Importance: Motor vehicle crashes (MVCs) are an important public health concern. Recent trends suggest that introducing rideshare services has decreased the incidence of MVCs. However, detailed analyses linking rideshare volume, convictions for impaired driving, and nonfatal MVC traumas remain inconclusive. Objective: To determine if there is an association between rideshare use and MVC traumas and convictions for impaired driving in Houston, Texas. Design, Setting, and Participants: This multicenter cohort study was conducted between January 2007 and November 2019 with hospital data from the Red Duke Trauma Institute within the Memorial Hermann Hospital-Texas Medical Center and Ben Taub General Hospital. Rideshare data from Uber and Google covered trips taken within Houston, Texas, from February 2014 (the date of deployment of Uber to Houston) to December 2018. Impaired driving convictions included all indictments made by the Harris County, Texas, District Attorney's office from January 2007 to December 2018. All adults with MVC traumas evaluated at both centers in the study population (individuals >16 years with a mechanism of injury classified under "motor vehicle collision") were included. Impaired driving incidents were included only if the final legal outcome was conviction. Main Outcomes and Measures: The primary study outcomes were the incident rate ratios for hourly MVC traumas and daily impaired driving convictions. Results: A total of 23 491 MVC traumas (involving patients with a mean [SD] age of 37.9 [17.8] years and 14 603 male individuals [62.1%]), 93 742 impaired driving convictions, and more than 24 million Uber rides were analyzed. Following the introduction of Uber in February 2014, MVC traumas decreased by 23.8% (from a mean [SD] of 0.26 [0.04] to 0.21 [0.06] trauma incidents per hour) during peak trauma periods (Friday and Saturday nights). The incident rate ratio of MVC traumas following Uber deployment was 0.33 (95% CI, 0.17-0.67) per 1000 indexed rides (P = .002). Furthermore, rideshare use was associated with a significant, geographically linked reduction in impaired driving convictions between January 2014 to December 2019 (incidence rate ratio, 0.76 [95% CI, 0.73-0.78]; P < .001). Conclusions and Relevance: In this study, introducing rideshare services in the Houston metropolitan area was associated with significant reductions in MVC traumas and impaired driving convictions. Increased use of rideshares may be an effective means of reducing impaired driving and decreasing rate of MVC traumas.