Influence of cannabis use history on the impact of acute cannabis smoking on simulated driving performance during a distraction task.

Objective: This research explores the driving performance of people who use cannabis daily or occasionally during distraction tasks performed following acute cannabis use.Methods: Healthy adults aged 25 to 45 years with different cannabis usage histories were recruited to participate in a within-subjects controlled experiment using a car-based driving simulator. Participants were classified as having daily use (n = 31), occasional use (1 or 2 times per week; n = 24), or no-use (n = 30). Participants completed a practice drive followed by four 5-10 minute driving scenarios during the baseline period. Participants then smoked self-procured cannabis flower ad libitum for up to 15 minutes. Thirty minutes later, they completed four additional 5-10 minute scenarios. Scenarios were paired according to difficulty and randomized across the baseline and post-use periods. Each scenario contained between 0 and 3 repetitions of a distraction task where the participant was prompted by an audio message to select an app from a 4 × 5 grid displayed on a mounted tablet, a step that would require briefly looking away from the roadway. Measures of driving performance (lane departures, standard deviation of lateral position) were assessed during the five-second period following the audio trigger and analyzed using generalized linear mixed models.Results: Those with a pattern of occasional use were significantly more likely to experience a lane departure during distraction periods after acute cannabis use relative to baseline (OR = 3.71, p = 0.04, CI = 1.04, 13.17), while those with daily use did not exhibit a similar increase (OR = 1.56, p = 0.43, CI = 0.52, 4.64). Changes in departure risk were significantly greater for the occasional use group compared to no-use (p = 0.02), but not for the daily use group compared to no-use (p = 0.18). However, following acute use, those who use daily exhibited decreases in speed relative to baseline in comparison to the changes observed in the no-use group (p = 0.02), while differences between occasional and no-use did not reach statistical significance (p = 0.052). Differences in standard deviation of lateral position were not statistically significant, likely due to the short duration of tasks.Conclusions: These results find the largest potential safety concerns associated with a pattern of occasional use, who displayed an increase in lane departures after acute cannabis smoking. Those in the daily use group decreased their speed, which may be interpreted as compensation for drug effects. Further research is needed to understand the effects during longer and more complex secondary tasks.

Evaluation of a population health strategy to reduce distracted driving: Examining all "Es" of injury prevention.

BACKGROUND: Cell phone use while driving (CPWD) increases the risk of crashing and is a major contributor to injuries and deaths. The objective of this study was to describe the evaluation of a multifaceted, evidence-based population health strategy for the reduction of distracted driving. METHODS: A multipronged campaign was undertaken from 2014 to 2016 for 16- to 44-year-olds, based on epidemiology, focused on personal stories and consequences, using the "Es" of injury prevention (epidemiology, education, environment, enforcement, and evaluation). Education consisted of distracted driving videos, informational cards, a social media AdTube campaign, and a movie theater trailer, which were evaluated with a questionnaire regarding CPWD attitudes, opinions, and behaviors. Spatial analysis of data within a geographic information system was used to target advertisements. A random sample telephone survey evaluated public awareness of the campaign. Increased CPWD enforcement was undertaken by police services and evaluated by ARIMA time series modeling. RESULTS: The AdTube campaign had a view rate of >10% (41,101 views), slightly higher for females. The top performing age group was 18- to 24-year-olds (49%). Our survey found 61% of respondents used handheld CPWD (14% all of the time) with 80% reporting our movie trailer made them think twice about future CPWD. A stakeholder survey and spatial analysis targeted our advertisements in areas of close proximity to high schools, universities, near intersections with previous motor vehicle collisions, high traffic volumes, and population density. A telephone survey revealed that 41% of the respondents were aware of our campaign, 17% from our print and movie theater ads and 3% from social media. Police enforcement campaign blitzes resulted in 160 tickets for CPWD. Following campaign implementation, there was a statistically significant mean decrease of 462 distracted driving citations annually (p = 0.001). CONCLUSION: A multifaceted, evidence-based population health strategy using the Es of injury prevention with interdisciplinary collaboration is a comprehensive method to be used for the reduction of distracted driving. LEVEL OF EVIDENCE: Therapeutic, level IV.

Investigating in-vehicle distracting activities and crash risks for young drivers using structural equation modeling.

Distracted driving has been considered one of the main reasons for traffic crashes in recent times, especially among young drivers. The objectives of this study were to identify the distracting activities in which young drivers engage, assess the most distracting ones based on their experiences, and investigate the factors that might increase crash risk. The data were collected through a self-report questionnaire. Most participants reported frequent cell phone use while driving. Other reported activities include adjusting audio devices, chatting with passengers, smoking, eating, and drinking. A structural equation model was constructed to identify the latent variables that have a significant influence on crash risk. The analysis showed that in-vehicle distractions had a high effect on the crash likelihood. The results also indicated that dangerous driving behavior had a direct effect on the crash risk probability, as well as on the rash driving latent variables. The results provide insight into distracted driving behavior among young drivers and can be useful in developing enforcement and educational strategies to reduce this type of behavior.

Falta de atenção ao conduzir veículo automotor como causa de acidentes de trânsito nas rodovias federais brasileiras / Distracted driving of a motor vehicle on Brazilian federal highways as a cause of traffic accidents

RESUMO: Introdução: Falta de atenção ao conduzir (FAC) veículo é tida como fator de risco em ascensão para Acidentes de Transporte Terrestre (ATT). Objetivo: Os objetivos deste estudo foram identificar a tendência do número de vítimas em acidentes por FAC e do número de infrações por uso de aparelho telefônico celular nas rodovias federais brasileiras e problematizar a categoria FAC tal como vem sendo empregada no país. Método: Estudo de séries temporais, com dados de acidentes com vítimas disponibilizados pela Polícia Rodoviária Federal, cuja causa tenha sido FAC, no período de 2007 a 2016, e dados de infrações por dirigir utilizando celular. Resultados: Identificou-se tendência de aumento mensal do número de vítimas de acidentes por FAC no país até meados de 2011 (variação percentual mensal - VPM = 0,57%), seguida de diminuição significante (VPM = -0,45%). As macrorregiões apresentaram comportamento similar, com exceção do Sudeste. Houve tendência de aumento mensal do número de infrações pelo uso de celular pelo condutor de 2007 a 2013. Conclusão: A tendência é de aumento mensal do número de vítimas decorrentes de FAC no Brasil e na maioria das macrorregiões até 2011, com posterior tendência de declínio. A inexatidão da expressão "falta de atenção" compromete a qualidade dos dados e, por consequência, o adequado dimensionamento das vítimas atribuível a esse fator de risco. A díade celular-condução pode estar na origem de acidentes com vítimas por FAC no país.

ABSTRACT: Introduction: Distracted driving (DD) of a motor vehicle is considered an increasing risk factor for land transport accidents. Objective: To identify the tendency in the number of victims in DD accidents and in the number of offences due to cell phone use on Brazilian federal highways, as well as analyze the DD category in depth as it is being used in the country. Method: A time series study with data on accidents with victims, made available by the Federal Highway Police, whose cause was distracted driving, from 2007 to 2016 and data on offences for driving using a cell phone. Results: There was a tendency towards a monthly increase in the number of distracted driving accident victims in the country up to mid-2011 (percentage monthly variation - PMV = 0.57%), followed by a significant decrease (PMV = -0.45%). Macro-regions showed similar behavior, except in the Southeast. There was a monthly increase in the number of offences caused by drivers using cell phones from 2007 to 2013. Conclusion: There was a tendency towards monthly increases in the number of victims of distracted driving in Brazil and in most macro-regions up to 2011, followed by a subsequent downward tendency. The inaccurate nature of the expression "distraction" compromises the quality of the data and, consequently, the adequate estimation of victims attributable to this risk factor. The cell phone-driving dyad could be the root cause of accidents with victims caused by distracted driving in the country.

Determining the incidence of distraction among trauma patients in all modes of transportation.

BACKGROUND: The use of distracting technology is an increasing source of risk for injury among trauma patients. Both drivers and pedestrians show increased unsafe behavior. The data for prevalence and risk for distraction in trauma has varied widely. Our hypothesis is that distraction is more highly prevalent and widely distributed among all mechanisms of injury and variety of trauma patients. METHODS: A 10-question survey of adult trauma victims at a Level I trauma center regarding distraction at time of event was performed, examining age, sex, ethnicity, education level, mode of injury and role in the accident (driver, passenger, pedestrian, bicyclist, motorcyclist). Multiple-variable logistic regression was performed to identify risk factors for distraction. RESULTS: From June 2016 to October 2018, 1,316 patients were surveyed, and 1,011 (76.8%) patients reported their role in the traffic accident. The prevalence of distraction was 21.73% among drivers, 9.01% among passengers, 16.50% among pedestrians, 20.00% among bicyclists, and 8.09% among motorcyclists. Males (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.26-2.67) as well as all Others (OR, 2.09; 95% CI, 1.10-3.98) showed statistically significant increased risk for distraction. Motorcyclist (OR, 0.25; 95% CI, 0.13-0.50) and passenger (OR, 0.37; 95% CI, 0.18-0.77) roles during collision were a lowered risk of distraction. Furthermore, Asian/Pacific Islanders (OR, 1.62; 95% CI, 0.94-2.79) trended toward being at greater risk for distraction. CONCLUSION: Distraction is prevalent among a wide range of traffic accident victims, not just drivers. Males as well as all Others are more likely to be distracted. In contrast, motorcyclists and passengers are less likely to be distracted. Further studies to assist in determining effective interventions and public safety efforts aimed at specific at-risk groups beyond motor vehicle drivers are warranted. LEVEL OF EVIDENCE: Epidemiological, level V.

Systematic review of observational studies on secondary task engagement while driving.

The last decade has seen a worldwide exponential increase in the use of mobile information systems, especially smartphones. This trend covers all areas of life, and also seems to include phone use while driving. In order to assess the scope of secondary task occupation, especially smartphone use while driving, observation studies from outside the car have been established as an efficient and valid method. A review of international studies using traffic observation was done finding 51 publications with a total of 117 observation studies with more than 1,800,000 single observations at more than 17,500 sites from nine different countries. The review describes the relevant aspects of the observation methods and gives an overview about the trends found in the data. As the methods differ widely over the years as well as between the countries and studies, an integration of the results is not possible. However, from all studies it is very clear that smartphone use has increased including not only phoning while driving but also, more important to traffic safety, using apps and texting on the smartphone. Additional observable secondary tasks were only rarely examined. Thus, further research using observational studies is strongly recommended. Suggestions are given with regard to the methodology which can contribute to get comparable and valid results across countries and studies.

Relationships Between Older Drivers' Cognitive Abilities as Assessed on the MoCA and Glance Patterns During Visual-Manual Radio Tuning While Driving.

Objective: Research has established that long off-road glances increase crash risk, and other work has shown increased off-road glance behavior in older drivers. This study investigated the relationship between older drivers' (M = 66.3, range 61-69 years) cognitive abilities and the duration of off-road glances while engaged in secondary visual-manual activities. Method: Twenty-two drivers completed the Montreal Cognitive Assessment (MoCA) prior to driving an instrumented vehicle and completing a set of radio-tuning tasks. Glance behavior was recorded and manually coded into 7 glance regions (toward the forward roadway, instrument cluster, center stack, rearview mirror, left, right, and other). Results: On average, older drivers with higher MoCA scores used shorter glances and glanced away from the forward roadway for less total time when manually tuning the radio. Discussion: These findings suggest that lower MoCA scores may represent a driving force behind the "age" differences reported in earlier studies of off-road glance behavior. Questions are raised concerning the identification of MoCA scores that might be used as inclusion cut-points in driving research and in identifying individuals needing further evaluation related to suitability for continuance of driving.

Using SHRP 2 naturalistic driving data to assess drivers' speed choice while being engaged in different secondary tasks.

INTRODUCTION: The engagement in secondary tasks while driving has been found to result in considerable impairments of driving performance. Texting has especially been suspected to be associated with an increased crash risk. At the same time, there is evidence that drivers use various self-regulating strategies to compensate for the increased demands caused by secondary task engagement. One of the findings reported from multiple studies is a reduction in driving speed. However, most of these studies are of experimental nature and do not let the drivers decide for themselves to (not) engage in the secondary task, and therefore, eliminate other strategies of self-regulation (e.g., postponing the task). The goal of the present analysis was to investigate if secondary task engagement results in speed adjustment also under naturalistic conditions. METHOD: Our analysis relied on data of the SHRP 2 naturalistic driving study. To minimize the influence of potentially confounding factors on drivers' speed choice, we focused on episodes of free flow driving on interstates/highways. Driving speed was analyzed before, during, and after texting, smoking, eating, and adjusting/monitoring radio or climate control; in a total of 403 episodes. RESULTS: Data show some indication for speed adjustment for texting, especially when driving with high speed. However, the effect sizes were small and behavioral patterns varied considerably between drivers. The engagement in the other tasks did not influence drivers' speed behavior significantly. CONCLUSIONS AND PRACTICAL APPLICATIONS: While drivers might indeed reduce speed slightly to accommodate for secondary task engagement, other forms of adaptation (e.g., strategic decisions) might play a more important role in a natural driving environment. The use of naturalistic driving data to study drivers' self-regulatory behavior at an operational level has proven to be promising. Still, in order to obtain a comprehensive understanding about drivers' self-regulatory behavior, a mixed-method approach is required.