Younger drivers executive functioning and the relationship with experiencing signs of sleepiness

Young drivers are more likely to continue driving when experiencing signs of sleepiness and are over-represented in sleep-related crashes. Adolescence and early adulthood are characterised by comparatively poor executive functioning, and while previous research has demonstrated a link between poor executive functions and several risky driving behaviours, the relationship with sleepy driving is not well understood. Accordingly, the first aim of the current study was to examine the association between executive functions and experiencing the signs of driver sleepiness in a sample of young adult drivers. Additionally, young drivers who have less experience with driving while sleepy, may attribute less importance to the signs of sleepiness as an indicator of underlying sleepiness level. To test this assumption (aim two), the impact of experiencing signs of sleepiness on perceptions of the importance of those signs was examined. Participants included 118 young adults aged between 17 and 25 years, who completed an online survey measuring experiences with the signs of sleepiness while driving, executive functions, and demographic characteristics. This sample of young adults reported having considerable experience with several signs of sleepiness (i.e., yawning, mind wandering, and difficulty keeping eyes while driving). A linear regression analysis found that the demographic variables of age and hours driven per week, as well as the executive function constructs of organization, strategic planning, and impulse control were associated with experiencing signs or sleepiness. Moreover, having experienced more signs of sleepiness was associated with an increased likelihood in rating those signs as important indicators of sleepiness. The current findings suggest both that several high-level cognitive processes as well as levels of experience with driving when experiencing signs of sleepiness contribute to young peoples’ sleepy driving.     

Factors in the fatigue of heavy vehicle drivers

This study assessed work-related and driver-related factors in fatigue among Finnish heavy vehicle drivers. 683 professional drivers responded to a questionnaire, 27.8% of whom reported often feeling fatigue during their work shifts. Of the respondents, 27.5% reported having momentarily fallen asleep at the wheel while driving during the past year. Almost half (46.8%) of the fatigued drivers estimated the reasons for momentarily falling asleep were work-related. Long working shifts and short sleeps significantly increased the risk of momentarily falling asleep at the wheel. The risk of fatigue was the highest for the drivers who were unable to choose the time of their breaks.     

Age and gender comparisons of driving while sleepy: Behaviours and risk perceptions

To assist road safety professionals in developing effective strategies to combat the risk associated with driving while fatigued, a survey was administered to 1000 Australian drivers. Participants reported their past behaviours in regards to driving while sleepy and their perceptions of risk associated with driving fatigued as compared to speeding and driving under the influence of alcohol. Although participants appeared to be aware of the substantial risk associated with driving while sleepy, many drivers reported that they frequently drive when sleepy. Age and gender comparisons, revealed that risk taking behaviour in regards to driving while sleepy is occurring across all age groups and in both male and female drivers. Overall young to middle age drivers and male drivers reported the highest frequency of driving while sleepy and reported the lowest perceived personal risk in regards to driving while sleepy.     

Efficacy of proxy definitions for identification of fatigue/sleep-related crashes: An Australian evaluation

Fatigue/sleepiness is recognised as an important contributory factor in fatal and serious injury road traffic incidents (RTIs), however, identifying fatigue/sleepiness as a causal factor remains an uncertain science. Within Australia attending police officers at a RTI report the causal factors; one option is fatigue/sleepiness. In some Australian jurisdictions police incident databases are subject to post hoc analysis using a proxy definition for fatigue/sleepiness. This secondary analysis identifies further RTIs caused by fatigue/sleepiness not initially identified by attending officers. The current study investigates the efficacy of such proxy definitions for attributing fatigue/sleepiness as a RTI causal factor. Over 1600 Australian drivers were surveyed regarding their experience and involvement in fatigue/sleep-related RTIs and near-misses during the past five years. Driving while fatigued/sleepy had been experienced by the majority of participants (66.0% of participants). Fatigue/sleep-related near misses were reported by 19.1% of participants, with 2.4% being involved in a fatigue/sleep-related RTI. Examination of the characteristics for the most recent event (either a near miss or crash) found that the largest proportion of incidents (28.0%) occurred when commuting to or from work, followed by social activities (25.1%), holiday travel (19.8%), or for work purposes (10.1%). The fatigue/sleep related RTI and near-miss experience of a representative sample of Australian drivers does not reflect the proxy definitions used for fatigue/sleepiness identification. In particular those RTIs that occur in urban areas and at slow speeds may not be identified. While important to have a strategy for identifying fatigue/sleepiness related RTIs proxy measures appear best suited to identifying specific subsets of such RTIs.     

Differential effects of driver sleepiness and sleep inertia on driving behavior

ObjectivesDriver sleepiness is one of the major safety issues in conventional driving and sleep inertia emerges as a driver state in automated driving. The aim of the present study was to assess the differential impacts of sleepiness and sleep inertia on driving behavior.Method61 participants completed a 10-min manual driving task during an otherwise automated drive. They completed the task (a) under an alert state, (b) under a sleepy state, and (c) after EEG-confirmed sleep. Driving performance was assessed with the parameters lane-keeping, speed choice, and speed-keeping. The eye-blink-based sleepiness measure PERCLOS (the proportion of time with eyes closed) was compared for the three driver states.ResultsLane- and speed-keeping performance were impaired under the sleepy state and after sleep, relative to the alert state. After sleep, lane-keeping behavior recovered rapidly and speed-keeping recovered by trend. Under the sleepy state, performance deteriorated. After sleep, the mean speed was lower than in the sleepy state and in the alert state. PERCLOS was increased after sleep and under the sleepy state, relative to the alert state.ConclusionsAlthough sleep inertia had detrimental effects on driving parameters similar to sleepiness, this effect rapidly vanished. Hence, while brief naps might be suitable to restore alertness in general, the minimal time needed to regain full capacity after napping should be a focus of future research.     

A driving simulator study to assess driver performance during a car-following maneuver after switching from automated control to manual control

A review of the literature on autonomous vehicles has shown that they offer several benefits, such as reducing traffic congestion and emissions, and improving transport accessibility. Until the highest level of automation is achieved, humans will remain an important integral of the driving cycle, which necessitates to fully understand their role in automated driving. A difficult research topic involves an understanding of whether a period of automated driving is likely to reduce driver fatigue rather than increase the risk of distraction, particularly when drivers are involved in a secondary task while driving. The main aim of this research comprises assessing the effects of an automation period on drivers, in terms of driving performance and safety implications. A specific focus is set on the car-following maneuver. A driving simulator experiment has been designed for this purpose. In particular, each participant was requested to submit to a virtual scenario twice, with level-three driving automation: one drive consisting of Full Manual Control Mode (FM); the other comprising an Automated Control Mode (AM) activated in the midst of the scenario. During the automation mode, the drivers were asked to watch a movie on a tablet inside the vehicle. When the drivers had to take control of the vehicle, two car-following maneuvers were planned, by simulating a slow-moving vehicle in the right lane in the meanwhile a platoon of vehicles in the overtaking lane discouraged the passing maneuver. Various driving performances (speeds, accelerations, etc.) and surrogate safety measures (PET and TTC) were collected and analysed, focusing on car-following maneuvers. The overall results indicated a more dangerous behavior of drivers who were previously subjected to driving automation; the percentage of drivers who did not apply the brakes and headed into the overtaking lane despite the presence of a platoon of fast-moving vehicles with unsafe gaps between them was higher in AM drive than in FM drive. Conversely, for drivers who preferred to brake, it was noted that those who had already experienced automated driving, adopted a more careful behavior during the braking maneuver to avoid a collision. Finally, with regard to drivers who had decided to overtake the braking vehicle, it should be noted that drivers who had already experienced automated driving did not change their behavior whilst overtaking the stopped lead vehicle.     

Characteristics of college students who text while driving: Do their perceptions of a significant other influence their decisions?

IntroductionTexting while driving is a significant risk factor for automobile collisions. The use of cell phones is prevalent among young people and commonly reported when they drive.MethodA web-based survey of 861 college student drivers determined how texting was associated with other forms of risky driving, perceptions of risk, and their driving and texting interactions with a significant other.ResultsTexting drivers were more likely to engage in other risky driving behaviors, perceived less risk in texting and driving, felt more immune to traffic risks, and had friends who text and drive. Logistic regression analyses showed that even after adjusting for risky driving behaviors and perceived risk, texting drivers were significantly more likely to do so if they saw their significant other text and drive.ConclusionsTraffic safety campaigns need to address important social influences on this behavior.     

Drinking and driving “safely”: Who uses a breathalyzer and when?

Breathalyzers are often promoted on the grounds of safety. However, drivers who use them to avoid illegal blood-alcohol levels inadvertently expose themselves to sleepiness-related risks following alcohol intake. Personal breathalyzers may even be counterproductive if they make more drivers engage in more frequent or habitual drinking and driving. This study explores the extent to which and how drivers use the breathalyzer. We contacted nine major breathalyzer importers in Finland and found out that the estimated number of devices delivered during 2006 was almost 50,000, equaling approximately one percent of population and one-and-a-half percent of driving-license holders. Survey data on a representative sample of Finnish active drivers (N = 1121) showed that 11.5% owned a breathalyzer. More men than women own and use a breathalyzer, and most often the men are aged 36–55 years. These men also use it more often after acute drinking (32% vs. 20% in the whole sample). Seventy-nine percent of breathalyzer use occurs the following day after evening or night drinking. Therefore, while in a smaller percentage of cases the risk involves the additive and interactive effects of alcohol and sleepiness in the evening, most users expose themselves to risks related to daytime sleepiness due to drinking the previous night.     

The self-reported causes of sleepiness in shift-working tram and truck drivers

Identifying the causes of sleepiness in various safety-critical work environments is necessary for implementing more efficient fatigue management strategies. In transportation, little is known about drivers’ own perceptions of these causes. Therefore, we instructed shift-working tram (n = 23) and long-haul truck drivers (n = 52) to report at the end of their shifts what made them sleepy if they felt so. These self-reports, measured on-duty sleepiness, and sleep amounts were recorded on every shift over a period of 2–3 weeks per driver. The causes of sleepiness were queried with smartphone applications and sleep logs. Sleepiness was measured with the Karolinska Sleepiness Scale (KSS) and sleep with wrist-worn actigraphs. Data were analyzed using generalized estimating equations. Sleep loss and insufficient rest breaks were commonly reported as causing sleepiness among the tram drivers, whereas time of day and sleep loss were the leading causes among the truck drivers. Other causes, such as traffic or cabin conditions, were not frequently mentioned. During morning, day, and evening shifts, the truck drivers were less likely to report insufficient rest breaks as causing sleepiness than the tram drivers. Similarly, during morning shifts, the truck drivers were less likely to attribute their sleepiness to sleep loss. In shifts with drives reporting severe sleepiness (KSS ≥ 7 at least once, 18–21% of shifts), sleep loss was significantly reported as causing sleepiness among both groups. Reporting insufficient rest breaks was associated with severe sleepiness among the tram drivers, whereas time of day showed the same among the truck drivers. The results highlight the need for addressing sleep-related fatigue in transportation and provide directions for future research with regard to secondary causes of sleepiness.     

Contributory factors to sleepiness amongst London bus drivers

Driver sleepiness contributes to a substantial proportion of all road crashes. Despite all that is known about driver sleepiness, bus drivers are often overlooked. What is certain is that bus drivers have the potential to suffer from sleepiness as they are shift workers. The current research used a large online survey to investigate sleepiness amongst London bus drivers. There were two aims; to quantify the prevalence of sleepiness amongst London bus drivers, and to determine the factors which contributed to sleepiness. Overall, 20.8% of respondents indicated that they had to fight sleepiness at least 2–3 times a week, and 36.6% of respondents stated that they had experienced a close call due to sleepiness in the past year. There were several potential causes of sleepiness including work, sleep, and personal factors such as obtaining less than 11 h rest between shifts, working 6 or more days without a rest day, and poor self-reported health. These findings show that sleepiness is common amongst London bus drivers and is caused by a combination of factors. The combination of contributory factors suggests that a multifaceted approach should be taken to reduce bus driver sleepiness.     

Mobile phone use while driving-literary review

This paper analysis published results of the research into the connection between mobile phone use while driving and traffic safety. Ever since the introduction of the first mobile phones, the authors have been examining the risks associated with its use in traffic, namely: prevalence or frequency of mobile phone use while driving, characteristics of drivers who make more frequent use of mobile phones, the connection between mobile phone use while driving and a car crash risk, a link between mobile phone use while driving and perception of risk, effects on driving performance of using various modes of mobile phones while driving (“hands-free” or “hand-held”), psychological factors influencing driver's decision to use a mobile phone while driving, etc.It is important to point out that the results of some studies indicate that using a hands-free mobile phone while driving does not provide greater safety as compared to the use of hand-held mobile phones while driving. Generally speaking, younger male drivers tend to use mobile phones more often while driving than women and older males.This paper analyses the results of studies which were published in 60 papers from 1994 to 2013.The analysis of the papers selected for research confirms detrimental effects of mobile phone use while driving. Also, four phases in the process of understanding the issue of mobile phone use impacts while driving have been established or identified. The first phase gives the analysis of the prevalence or frequency of mobile phone use while driving. The second phase identifies the characteristics of drivers who tend to use mobile phones more frequently while driving. The third phase concerns research into impacts of using different modes of mobile phones while driving on driving performance (“hands-free” or “hand-held”). Finally, the fourth phase deals with research into risks of mobile phone use while driving (“hands-free” or “hand-held”). The importance of this paper is reflected in that it can help traffic safety policy makers, on the basis of better understanding of the issue of mobile phone use impact while driving, to develop effective strategies aimed at reducing the extent of mobile phone use while driving.     

Hazard perception performance and visual scanning behaviours: The effect of sleepiness

Driver sleepiness accounts for a substantial proportion of crashes in Australia and Worldwide. Young adults are overrepresented in sleep-related crashes and are more susceptible to sleepiness, resulting in impaired attention and driving performance. Visual scanning behaviour can affect the role between attention and information acquisition from the driver's environment. Thus, if attention is impaired, visual scanning behaviours are likely to show decrements as well. Overall, 32 young adults aged between 20 and 25 years completed a 60-minute hazard perception task to examine the effect of sleepiness and time-on-task on hazard perception performance, visual scanning behaviours, subjective sleepiness scores, and psychomotor vigilance test performance. The main outcomes include decrements in hazard perception performance and a restriction in horizontal and vertical eye scanning ranges across the 60-minute session, but with a more pronounced effect when sleep-restricted. These outcomes were consistent with increases in subjective sleepiness and behavioural metrics of sleepiness assessed via the PVT. Reductions in scanning range could limit opportunities to attend to hazards and other critical safety events. The current study outcomes provide an important contribution regarding the risks associated with sleepy driving performance.     

Attitudes and behaviors associated with young drivers’ texting and app use

IntroductionDistracted driving is a major risk factor for motor vehicle crashes, especially for young drivers. This study examines factors that contribute to the exposure of young drivers to distracted driving behaviors.MethodsData from the 2015 National Survey on Distracted Driving Attitudes and Behaviors was used to determine the influence that perceived safety, likelihood to do or say something, social norms, and demographic variables have on self-reported cell phone distracted driving. Our population included 16–24-year old drivers. Dependent variables were texting (reading and sending a text/email) and smartphone app use while driving. Rao-Scott chi-squared tests and multivariate logistic regression models were applied. Sampling weights were applied to create nationally representative estimates and all statistical tests accounted for complex survey design.ResultsAmong young drivers who report cell phone use while driving, 42% reported reading a text, 33% reported sending a text, and 23% reported smartphone app use. Multivariate regression results showed that perceived safety had the strongest association with reporting texting and smartphone app use while driving. In addition, social norms and age-education were significantly associated with reporting sending a text/email and reading a text/email while driving, respectively.ConclusionsThe current study found significant relationships between attitudes and behaviors about cell phone use while driving and self-reported engagement in distracted driving.Practical applicationsInterventions with an emphasis on changing perceived safety and social norms for young drivers could be beneficial for reducing engagement in cell phone use while driving.     

Hanging on the telephone: Mobile phone use patterns among UK-based business travellers on work-related journeys

There is currently only limited understanding of the driving-related phone use patterns of business travellers. This paper addresses this gap in knowledge by presenting the findings of a UK-based study on the extent to which, and ways in which, people on work-related journeys use mobile phones while driving. A sample of 149 UK drivers who used a particular motorway service station were surveyed, with follow up interviews being conducted with 15 survey respondents. It was found that such drivers made frequent and extensive use of mobile phones, with over 50% of survey respondents being categorized as ‘serial users’ of mobile phones while driving. Survey analysis also found that male drivers were significantly more likely than female drivers to be serial users. The interviews that were conducted highlighted the complexity of the decision making process drivers typically undertook in deciding whether and how to use their phones, which took account of factors such as the nature of road conditions and the type of call to be made or taken.     

Does awareness of penalties influence deterrence mechanisms? A study of young drivers’ awareness and perceptions of the punishment applying to illegal phone use while driving

This research implemented both qualitative and quantitative methods to 1) explore young drivers’ (aged between 17 and 25 years) awareness and perceptions of legal sanctions associated with phone use while driving and 2) identify whether the accuracy of their knowledge influences deterrence-related perceptions. In the qualitative phase, 60 Queensland motorists participated in focus groups. The findings of the focus groups highlighted that greater awareness of the penalty for phone use while driving would enable this punishment to act as a more salient deterrent. More specifically, the penalty for hands-free phone use was considered too high, whereas when the penalty was applied to hand-held phone use it was considered reasonable, with some commenting that increasing the fine could be a greater deterrent. However, the penalty also appeared to be linked to the perceived legitimacy of the rule. The quantitative phase utilised a cross-sectioanl survey design and consisted of 503 drivers. Overall, more participants appear to be underestimating (63% underestimated the fine and 37% underestimated the demerit points) as opposed to overestimating (14% overestimated the fine and 22% overestimated the demerit points) the penalty for phone use while driving. As expected, compared to those who accurately estimated the extent of the punishment (both the monetary sanction and the number of demerit points) associated with phone use while driving, drivers who underestimated the phone punishment (points and fine) had significantly lower perceptions of the severity of punishment. These findings suggest that some young drivers do not have sufficient knowledge of mobile phone sanctions, which has significant implications for ongoing attempts to maximise deterrent mechanisms.     

Identifying the main factors contributing to driving errors and traffic violations – Results from naturalistic driving data

Researchers have identified various factors that likely affect aberrant driving behaviors and therefore crash risk. However, it remains unclear which of these factors poses the greatest risk for either errors or violations under naturalistic driving conditions. This study investigated important variables contributing to driving errors and traffic violations based on naturalistic driving data from the second Strategic Highway Research Program (SHRP 2). In addition, this study identified factors determining the drivers’ willingness to perform common secondary tasks while driving, which have been associated with different degrees of crash risk. Results showed that anger, passenger presence, and persistent individual differences in driver behavior were the main factors associated with committed violations; surprise, high-risk visually distracting secondary tasks, and the driving task demand passing through an interchange were the main factors associated with errors. The willingness to engage in risky secondary tasks while driving appeared to be related to an overall tendency to engage in risky driving behaviors. However, drivers considered the driving context particularly when engaging in visually distracting secondary tasks. This study’s comprehensive approach should be a step towards generating a complete model of the variables that contribute to, or mitigate dangers in traffic.     

Survey of New Zealand truck driver fatigue and fitness for duty

This paper presents recent research into compliance with current driving hours regulations, the effectiveness of using driving hours to predict fatigue, and alternative compliance and enforcement options. The paper describes results of a major survey of truck driver fatigue in New Zealand, a review of international compliance and enforcement procedures, and research focussing on the social forces and influences that affect truck drivers. The survey of truck drivers was based on interviews and performance tests collected from 600 truck drivers at depots, wharves, markets, and other locations throughout the North Island of New Zealand. The interviews included: questions on driver demographic and work/rest patterns, drivers' attitudes towards fatigue, propensity towards daytime sleepiness, and a self-assessment of the driver's momentary level of fatigue. In addition, a simulator-based performance test of driving was undertaken. The performance test included a combination of a standard driving task, a dual-axis sub-critical tracking task (maintaining speed and steering in a controlled but unstable environment, a virtual roadway affected by the appearance of random wind gusts requiring steering correction), and a tertiary or side-task requiring driver monitoring and periodic responses. The initial results from the first 100 drivers have found a sizable number of drivers exceeding the allowable driving hours, high levels of fatigue and sleepiness, and interesting differences between line-haul and local delivery drivers. A related research project into the social processes and relationships that affect truck drivers has resulted in a good understanding of the social conditions that influence cultural change and the actions of truck drivers and fleet managers. In this paper we will have particular regard to these processes in the construction of ideas concerning safety. This includes an understanding of the role of major stakeholders, such as freight forwarders and the enforcement agencies with respect to drivers and their conditions, actions and understanding of the road transport industry. This knowledge coupled with the survey results and an understanding of compliance and enforcement alternatives will be used to explore potential fatigue management options.     

Psychological predictors of texting while driving among university students

Although text messaging while driving is illegal in Spain previous research has shown that a substantial proportion of drivers, particularly young drivers, engage in this risky behaviour. The present study set out to investigate the psychological predictors of this behaviour using the Theory of Planned Behaviour (TPB). This study also measured the drivers’ perceptions regarding the effectiveness of the ban on mobile phone use while driving, their perceived crash risk, the risk of being fined and the drivers perceived ability to compensate for the distraction caused by reading or writing text messages while driving. Data were collected using an online questionnaire from 1082 university students who were drivers and owned a mobile phone. Attitude and perceived behavioural control significantly predicted the intention to send and read text messages while driving, even after controlling for exposure and demographic variables. Furthermore, intention was found to be a significant predictor of retrospective measures of both sending and reading text messages while driving, as was perceived behavioural control for several of the outcome measures. The present findings provide support for the TPB and also demonstrate the additional contributions that the mobile phone ban and perceived ability to compensate for the distraction had in predicting intentions. In addition, perceived crash risk was positively related to the prediction of intentions to send text messages and the number of messages read in the last week. The implications of these findings are discussed.     

Analysis of contributory factors for driving under the influence of alcohol: A stated choice approach

This study adopts the stated choice modeling approach to explore the contributory factors and circumstances for driving after drinking. A total of 308 drivers who participated in the Traffic Safety Reeducation Program during the period between October 17 and November 5, 2010 in Taiwan were selected to answer the questionnaire. The survey results indicate that a relatively large proportion of respondents lack of full knowledge of drunk driving regulations and the effects of impaired levels on driving ability. The results of stated choice analysis further indicate that level of impairment, police enforcement, driver’s drinking habits and knowledge of drunk driving regulations can significantly affect drivers’ choice of driving after they drink.     

Support for distracted driving laws: An analysis of adolescent drivers from the Traffic Safety Culture Index from 2011 to 2017

IntroductionAdolescent drivers are often the focus of traffic safety legislation as they are at increased risk for crash-related injury and death. However, the degree to which adolescents support distracted driving laws and factors contributing to their support are relatively unknown. Using a large, nationally weighted sample of adolescent drivers in the United States, we assessed if perceived threat from other road users’ engagement in distracted driving, personal engagement in distracted driving behaviors, and the presence of state distracted driving laws was associated with support for distracted driving laws.MethodsThe sample included 3565 adolescents (aged 16–18) who participated in the Traffic Safety Culture Index survey from 2011 to 2017. A modified Poisson regression model with robust errors was fit to the weighted data to examine support for distracted driving laws. Models included age, gender, year, state distracted driving laws, personal engagement in distracted driving behavior, and perceived threat from other road users’ engaging in distracted driving.ResultsApproximately 87% of adolescents supported a law against texting and emailing compared to 66% who supported a universal handheld cellphone law. Support for distracted driving legislation was associated with greater perceived threat of other road users engaging in distracted driving while accounting for personal engagement in distracted driving, state distracted driving laws, and developmental covariates.DiscussionGreater understanding of the factors behind legislative support is needed. Public health interventions focused on effectively translating the risks of cellphone use while driving and effective policy will further improve the traffic safety culture.