Prediction of mood and risk appraisals from trait measures: Two studies of simulated driving

Fatigue and Secondary Media Impacts in the Automated Vehicle: A Multidimensional State Perspective

Safety researchers increasingly recognize the impacts of task-induced fatigue on vehicle driving behavior. The current study (N = 180) explored the use of a multidimensional fatigue measure, the Driver Fatigue Questionnaire (DFQ), to test the impacts of vehicle automation, secondary media use, and driver personality on fatigue states and performance in a driving simulator. Secondary media included a trivia game and a cellphone conversation. Simulated driving induced large-magnitude fatigue states in participants, including tiredness, confusion, coping through self-comforting, and muscular symptoms. Consistent with previous laboratory and field studies, dispositional fatigue proneness predicted increases in state fatigue during the drive, especially tiredness, irrespective of automation level and secondary media. Similar to previous studies, automation slowed braking response to the emergency event following takeover but did not affect fatigue. Secondary media use relieved subjective fatigue and improved lateral control but did not affect emergency braking. Confusion was, surprisingly, associated with faster braking, and tiredness was associated with impaired control of lateral position of the vehicle. These associations were not moderated by the experimental factors. Overall, data support the use of multidimensional assessments of both fatigue symptoms and information-processing components for evaluating safety impacts of interventions for fatigue.

ADHD, depression, and motor vehicle crashes: A prospective cohort study of continuously-monitored, real-world driving

ADHD is associated with automobile crashes, traffic fatalities, and serious road trauma, but it is unclear whether this risk is (a) driven by ADHD symptoms specifically, and (b) unique to ADHD or transdiagnostic across psychiatric disabilities, such as depression, that also have concentration problems as core symptoms. The current study provides the first prospective, continuously-monitored evaluation of crash risk related to ADHD symptoms, including the first on-road comparison of ADHD with another high-prevalence psychiatric disability (depression). A probability-based sample of 3226 drivers from six U.S. sites, including subsamples with self-reported ADHD (n = 274) and depression (n = 251), consented to have their vehicles outfitted with sophisticated data acquisition technologies to continuously monitor real-world, day-to-day driving from 'engine-on to engine-off' for 1-2 years (Mean = 440 consecutive days/driver, Mean = 9528 miles/driver). Crashes and near-crashes were objectively identified via software-based algorithms and double-coded manual validation (blinded to clinical status). Miles driven, days monitored, age, gender, education, and marital status were controlled. ADHD symptoms portended 5% increased crash risk per increase in symptom severity score (IRR = 1.05). This risk corresponded to approximately 1 biennial crash and 1 annual near-crash per driver with ADHD; crash risk doubled for drivers reporting ADHD symptom severity near the sample's maximum. Analyses based on self-reported clinical status indicated similarly elevated rates for ADHD (IRR = 1.46) and depression (IRR = 1.34) that may be related, in part, to both groups' inattention/concentration symptoms. Risk was not attenuated by ADHD usual treatment, but varied according to antidepressant medication status. Previous studies have significantly underestimated the risk for traffic crashes conveyed by ADHD and depression.

Perceptions, intentions and behavioral norms that affect pre-license driving among Arab youth in Israel

The present study examines reported pre-license driving among youth from the population of Arab citizens of Israel. The purpose of the present study is to examine which sociodemographic variables, attitudes and perceptions about safe driving and individual and societal behavioral norms are associated with pre-license driving. The research distinguished between the factors that actually contribute to pre-license driving (reported behavior, peer norms, gender and parents' messages) and the factors that explain the intention (parental authority, social norms, parents' messages and fear of road crashes). Even though there was a significant partial overlap (84%) between those who intend to drive without a license and those who reported driving without a license, the main factors that distinguish pre-license driving groups are different from the factors that distinguish the intention to drive before receiving a license. What is unique about the findings is the identification of the context in which social norms are influential and that in which parental authority is influential. The study indicated that in the case of pre-license driving, the main motivating factor is subjective norms, whereas in the case of expecting to drive without a license, the main motivating factor is the interaction between parental authority and the messages that parents convey. While actual behavior pertains to the behavioral level, we argue that intended behavior pertains to the cognitive level. At this level, rational considerations arise, such as fear of parental punishment and fear of accidents. These considerations compete with the influence of friends and their norms, and may outweigh them. The findings suggest that it is important to safeguard youth against the influence of peer pressure as early as the stage of behavioral intentions. Follow-up studies can simulate situations of pre-license driving due to social pressure and identify the factors that might affect young people's decision-making. Moreover, providing parents with training before the accompaniment period is highly recommended.

Individual Differences in Driver Stress and Performance

80 subjects high and low in vulnerability to driver stress participated in a study of simulated driving performance. Subjects completed the Driving Behaviour Inventory, which assesses vulnerability through a Dislike of Driving scale. Half the subjects performed in a ‘stress’ condition, in which they frequently lost control of vehicle steering, the remainder in a non-stressful control condition. Two performance measures were analyzed: response time (RT) on a secondary attentional task, and a measure of lateral tracking. The stress manipulation was more strongly related to longer RTs in high Dislike of Driving subjects than in low Dislike subjects. However, slowing of response was more pronounced on straight than on curved road sections, i.e. when the driving task is relatively undemanding. This finding suggests that stress-related impairment is not simply due to overload of attention. Instead, the stress-vulnerable driver may have difficulties in matching effort to task demands, with under-mobilisation of effort when the task appears relatively easy. Lateral tracking data were also consistent with this hypothesis. Self-report data suggested that the manipulation was generally effective in inducing subjective stress symptoms. However, high Dislike subjects tended to react to the manipulation with particularly high levels of intrusive thoughts and ‘cognitive interference’.

Validation of the Driver Stress Inventory in China: Relationship with dangerous driving behaviors

Perceived stress while driving may affect how critical driving events are handled. The current study validates a Chinese version of the Driver Stress Inventory (DSI) and explores its correlation with dangerous driving behaviors and gender. A sample of 246 drivers completed the Chinese version of the DSI and the Driver Behavior Questionnaire (DBQ). We also evaluated specific sociodemographic variables and traffic violations (including speeding, violating traffic signs or markings, driving while intoxicated, running a red light, and incurring penalty points). A confirmatory factor analysis (CFA) verified the DSI's internal structure. The DSI was also validated using questionnaires related to the DBQ, self-reported traffic accidents and violations, and sociodemographic characteristics. First, all of the DSI dimensions were moderately or weakly correlated with the DBQ subscales. Second, aggression, hazard monitoring and fatigue were weakly correlated with minor accidents. Third, drivers who had sped and violated traffic signs during the previous three years reported higher aggression and thrill seeking, while drivers who had violated traffic signs or markings during the previous three years reported decreased hazard monitoring compared with non-offenders. Finally, there were significant gender differences in driver stress. The Chinese version of the DSI will be useful for classifying and diagnosing drivers who may be at an increased risk for stress reactions.

Sadder but Wiser? Effects of Negative Emotions on Risk Perception, Driving Performance, and Perceived Workload

Traditional affect research has frequently used a valence dimension—positive and negative states. However, these approaches have not discriminated the effects of distinct emotions of the same valence. Recent findings have indicated that different emotions may have different impacts even though they belong to the same valence. The current study consists of a simulated driving experiment with two induced affective states to examine how sadness and anger differently influence driving-related risk perception, driving performance, and perceived workload. Thirty two undergraduates drove under three different road conditions with induced sadness, anger, or neutral emotions. Participants in both affect conditions showed significantly more errors than those in the neutral condition. However, only participants with induced anger reported significantly higher perceived workload than participants with neutral. Results are discussed in terms of affect mechanisms and design directions for the in-vehicle emotion regulation system.

Attributions and personality as predictors of the road rage response

This study examined the ability of attributions and personality traits to predict the emotional and behavioural components of the road rage response. Participants recalled a recent time when they experienced three different anger-provoking events when driving. They then rated their behaviours and emotions during the event, and their attributions for why the event occurred. Participants also completed a battery of personality questionnaires designed to predict their responses to the situations. Attributing causality for the anger-arousing event to a stable factor in the offending driver was uniquely related to aggressive behaviour and anger in all three situations. Hostile and blame attributions predicted aggressive behaviour and anger in different situations. In addition to dispositional measures of aggressiveness and anger predicting aggressive behaviour and anger in each of the anger-provoking situations, other personality variables were also related to aspects of the road rage response (e.g. conscientiousness, agreeableness, narcissism, and extraversion). Attributions and personality traits accounted for unique variance in the outcomes, and there were only sporadic effects of attributions partially mediating the relationships between personality variables and responses to the anger-provoking situations. Therefore, it is unlikely that the relationships between personality traits and responses to anger-provoking situations are completely mediated by attributional processing.

Development and validation of a self-report measure of bus driver behaviour

There are likely to be individual differences in bus driver behaviour when adhering to strict schedules under time pressure. A reliable and valid assessment of these individual differences would be useful for bus companies keen to mitigate risk of crash involvement. This paper reports on three studies to develop and validate a self-report measure of bus driver behaviour. For study 1, two principal components analyses of a pilot questionnaire revealed six components describing bus driver behaviour and four bus driver coping components. In study 2, test-retest reliability of the components were tested in a sub-sample and found to be adequate. Further, the 10 components were used to predict bus crash involvement at three levels of culpability with consistently significant associations found for two components. For study 3, avoidance coping was consistently associated with celeration variables in a bus simulator, especially for a time-pressured drive. STATEMENT OF RELEVANCE: The instrument can be used by bus companies for driver stress and fatigue management training to identify at-risk bus driver behaviour. Training to reduce the tendency to engage in avoidance coping strategies, improve evaluative coping strategies and hazard monitoring when under stress may improve bus driver safety.

Driving styles among young novice drivers--the contribution of parental driving styles and personal characteristics

As part of the effort to ascertain why young drivers are more at risk for car crashes, attention has recently turned to the effects of family, including the intergenerational transmission of driving styles from parents to offspring. The current study sought to further understanding of the nature and aspects of the family influence with the help of Bowen's family systems theory. In Phase 1 of the prospective study, 130 young driving students completed questionnaires tapping personal and personality measures, and their parents completed driving-related instruments. In Phase 2, a year after the young drivers had obtained their driver's license, they were administered the same questionnaires their parents had previously completed. The results show significant correlations between the parents' driving styles and those of their offspring a year after licensure. Furthermore, differentiation of self and self-efficacy in newly acquired driving skills were found to moderate or heighten the similarity between the driving styles of parents and their offspring. For young drivers reporting anxiety in Phase 1, this was associated with a reported anxious driving style a year later. Among young female drivers, anxiety was also associated with a reckless and careless style. Higher sensation seeking was related to higher reckless driving among young male drivers. The findings are discussed in the context of adolescence and the role of the study variables in the development and intergenerational transmission of driving styles. In addition to its theoretical contribution to the realms of intergenerational transmission in general, and young drivers in particular, the study may have practical implications for both family therapy and the design of driving interventions.

Stress, fatigue, health, and risk of road traffic accidents among professional drivers: the contribution of physical inactivity

Strategies to achieve ambitious targets for reducing road accidents ( 34 ) have largely focused on engineering and technological advancements, the modification of occupational demands, and, to a lesser extent, human factors. These factors include stress and psychological states; sleep, fatigue, and alertness; and health status. Physical activity appears to influence all these human factors but has not previously been systematically considered as a direct or indirect risk factor for driver accidents. This chapter provides an overview, within an evidence-based framework, of the impact each of these human factors has on driver performance and risk of at-work road traffic accidents and then examines how physical (in)activity may moderate and mediate these relationships. Finally, we consider practical implications for work site interventions. The review aims to offer an evidence base for the deployment of resources to promote physical activity, manage stress, facilitate sleep, reduce fatigue, and enhance alertness to improve physical and psychological health among professional drivers.

Driver stress and performance on a driving simulator

Effects of stress on driving performance can depend on the nature of driver's stress reactions and on the traffic environment. In an experimental study, we assessed multiple dimensions of vulnerability to driver stress by a questionnaire that was validated in previous field studies and related those dimensions to performance on a driving simulator. Results were broadly consistent with prediction. A dimension of habitual dislike of driving was associated with reduced control skills, greater caution, and disturbance of moods. A measure of aggressive driving predicted more frequent and more error-prone overtaking, which are effects attributed to the use of confrontive coping strategies in interaction with other vehicles. An alertness measure predicted speed of reaction to pedestrian hazards. This research has practical applications for system design, automated monitoring of driver performance, selection and assessment of drivers, and training.