Relationships between personality facets and accident involvement among truck drivers

Prior research on the personality characteristics of truck drivers and accident involvement has relied primarily on the Big Five personality factors (e.g., Extraversion), and has largely focused on self-reported number of accidents rather than more objective, independent records. We examined the association between personality characteristics and accidents among professional truck drivers at the facet level of personality using company records of accidents over time. Analyses suggested that more empathetic individuals had lower rates of accident involvement, whereas more anxious, guilt-prone, exhibitionistic, and risk-taking individuals had higher rates. We discuss implications for decreasing rates of accidents, the selection of drivers, and use in other industries where physical safety is a concern.     

Driver fatigue among military truck drivers

The Israeli Defense Force (IDF) Transport Center is the largest and the most diverse transportation organization in Israel: three times as large as the largest commercial fleet in Israel, and military bases are spread all over the country. It also has the ability to regulate the drivers better: enforcing diet, hours of sleep, and working hours. The drivers are either permanently employed civilians, career service personnel, or mandatory service personnel. This employment status correlates with age, experience, carrier type, and several job characteristics (for example mandatory service drivers typically do not drive at night).The study consisted of a survey of 314 male drivers (30% of the entire base driver population). Despite the different environment, the military drivers display many characteristics and coping-behaviors characteristic of civilian drivers. Our results cast a doubt on the efficacy of enforcing night sleep and prohibiting night drives as an alternative to regulating hours of service. Our findings also reveal that it is insufficient to provide drivers with the time to sleep. One has to ensure that they also get a good quality of sleep. Implications for reducing fatigue in this environment are suggested. We identified the mandatory service drivers (young, less experienced drivers, lower military ranks) as a group of drivers that falls asleep more often and to a greater extent. They are particularly sensitive to sleep deficits and influenced by external events such as aggravation and boredom.It is important to provide drivers with more in-vehicle, accessible countermeasures to counter fatigue since they often do not stop, particularly in short-haul conditions. Since the radio has a high level of usage and acceptance among drivers, it could be exploited as an interactive communications system, as an educational medium, and as an image-enhancing device.     

Effects of partial sleep deprivation: A comparative assessment of young non-professional and professional taxi drivers

AimThis study aims to determine the effects of partial sleep deprivation (PSD) on driving performance of professional and young non-professional drivers.MethodsThe study included fifty participants (20 professional taxi drivers and 30 young non-professional drivers) driving the simulator-cab in three conditions. The first test session (TS1) was conducted after one night of PSD followed by the second test (TS2) after two consecutive nights of PSD. The driving performance metrics in two conditions of PSD (i.e., sleep duration = 4.25 ± 0.5 h) were compared with the baseline drive with no sleep loss. Sleep restriction was monitored using Actiwatch. Drivers subjectively self-reported their alertness using Karolinska Sleepiness Scale (KSS). Driving performance metrics and reaction time to emergency events were collected during each drive.ResultsA preliminary mixed-design ANOVA showed deterioration in driving performance of all drivers in terms of speed (p < 0.1), speed variability (p = 0.06), standard deviation in lateral positions (SDLP) (p < 0.001) and delayed reaction time (p < 0.05). Separate Mixed-Effects Generalized Linear Models for professional and non-professional drivers showed that speed variability, SDLP and reaction time increased from baseline during both the PSD tests, among both the driving groups. The speed variability, SDLP and reaction time of professional drivers differed significantly from other drivers under PSD conditions. Contrary to the existing belief, the professional drivers had significant decrements in driving performance due to PSD.ConclusionA critical and comparative analysis revealed that driving experience/skill of professional drivers does not improve their resistance to deteriorating effects of sleep loss.     

Fatigue risk management based on self-reported fatigue: Expanding a biomathematical model of fatigue-related performance deficits to also predict subjective sleepiness

Biomathematical models of fatigue can be used to predict neurobehavioral deficits during sleep/wake or work/rest schedules. Current models make predictions for objective performance deficits and/or subjective sleepiness, but known differences in the temporal dynamics of objective versus subjective outcomes have not been addressed. We expanded a biomathematical model of fatigue previously developed to predict objective performance deficits as measured on the Psychomotor Vigilance Test (PVT) to also predict subjective sleepiness as self-reported on the Karolinska Sleepiness Scale (KSS). Four model parameters were re-estimated to capture the distinct dynamics of the KSS and account for the scale difference between KSS and PVT. Two separate ensembles of datasets – drawn from laboratory studies of sleep deprivation, sleep restriction, simulated night work, napping, and recovery sleep – were used for calibration and subsequent validation of the model for subjective sleepiness. The expanded model was found to exhibit high prediction accuracy for subjective sleepiness, while retaining high prediction accuracy for objective performance deficits. Application of the validated model to an example scenario based on cargo aviation operations revealed divergence between predictions for objective and subjective outcomes, with subjective sleepiness substantially underestimating accumulating objective impairment, which has important real-world implications. In safety-sensitive operations such as commercial aviation, where self-ratings of sleepiness are used as part of fatigue risk management, the systematic differences in the temporal dynamics of objective versus subjective measures of functional impairment point to a potentially significant risk evaluation sensitivity gap. The expanded biomathematical model of fatigue presented here provides a useful quantitative tool to bridge this previously unrecognized gap.     

Driver distraction in long-haul truck drivers

Research on driver distraction has typically been conducted by means of epidemiology or experimental testing. The study presented here uses a naturalistic approach, where real-world driving data were collected from truck drivers as they worked their normal delivery runs. Crash, near-crash, and crash-relevant conflict data from 41 long-haul truck drivers, driving approximately 140,000 miles, were examined. Of the 2737 crashes, near-crashes, and crash-relevant conflicts (collectively termed “critical incidents”) that were recorded, 178 were attributed to “driver distraction”. The 178 distraction-related critical incidents were analyzed and 34 unique distraction types were identified. Results showed that a small number of long-haul drivers were involved in a disproportionate number of distraction-related critical incidents. For example, two of the drivers accounted for 43 of the 178 distraction incidents. Important insight was also gained into the relative safety impacts of different distracting agents and behaviors. The frequency and duration of a task, along with the visual demand associated with performing the task, were found to contribute in combination to the prevalence of critical incidents. Finally, it was found that simply because a task does not necessarily require visual attention does not mean that long-haul drivers will not look (sometimes often) away from the roadway. However, it is also clear that visually demanding tasks carry the highest degree of risk, relative to other categories of tasks.     

The relationship between self-reported received and perceived social support: A meta-analytic review

Social support is broad term encompassing a variety of constructs, including support perceptions (perceived support) and receipt of supportive behaviors (received support). Of these constructs, only perceived support has been regarded as consistently linked to health, and researchers have offered differing assessments of the strength of the received-perceived support relationship. An overall estimate of the received-perceived support relationship would clearly further the dialogue on the relationship between received and perceived support and thus assist in the theoretical development of the field. This study evaluated all available studies using the Inventory of Socially Supportive Behaviors (ISSB; Barrera, Sandler, & Ramsey, 1981, American Journal of Community Psychology, 9, 435–447) and any measure of perceived social support. Using effect sizes from 23 studies, we found an average correlation of r = .35, p < .001. Implications of this estimate for further development of models of social support as well as interventions to enhance social support are discussed.     

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.     

Sex differences in the causes of self-reported adolescent delinquency

Sex differences in the causes of self-reported adolescent delinquency were examined in full and half siblings born to a nationally representative sample of women in the United States. Qualitative sex differences in the genes that influence delinquency were not detected. Similarly, the proportions of variance in both aggressive and nonaggressive delinquency attributable to genetic and environmental influences did not differ significantly between girls and boys. Nonetheless, total variance in delinquency was greater among boys, and a scalar sex-differences model suggested that genetic and environmental influences on delinquency have less effect on population variation in delinquency among girls. Similarly, a test of the polygenic multiple threshold model suggested that girls require greater causal liability for the expression of delinquency than boys.     

Supervisor undermining and driving errors in truck drivers: A moderated mediation model

The present study focuses on the detrimental impact of supervisor undermining behaviors at work on driving errors for truck drivers, arguing for the mediating role of burnout. Moreover, this research highlights the moderating role of general self-efficacy in the relationships between supervisor undermining and burnout, and between burnout and driving errors, respectively. The data collected from a sample of 190 Romanian drivers supported a moderated mediation model in which burnout partially mediates the relation between supervisor undermining and driving errors, while self-efficacy moderates both aforementioned relationships. The conditional indirect effect of supervisor undermining on driving errors was significant when self-efficacy was low and non-significant when self-efficacy was high. Overall, our results emphasize the negative impact that supervisor undermining and burnout have on driving errors, while also highlighting the buffering effect of self-efficacy.     

High perceptual load causes inattentional blindness and deafness in drivers

ABSTRACT

Perceptual load theory of attention predicts that the level of perceptual load in a primary task affects the processing of additional stimuli. Given the lack of ecologically valid evidence for the model, the current study assessed the effect of perceptual load on driver awareness during simulated driving tasks. The results showed that perceptual load dramatically affected driver awareness for visual and auditory stimuli, even those that were driving relevant and safety critical (e.g. pedestrians or the sound of a car horn). The results support load theory and suggest that perceptual load may be an important factor in driver safety.     

Patterns in perceived crash risk among male and female drivers with and without substantial cycling experience

Perceived risk of crashes is generally higher in female than in male cyclists. No study has assessed whether these gender differences only apply to riding bicycles. Using an online risk assessment task and survey, this study (a) tested the hypothesis that compared to men, women perceive higher risks, irrespective of traffic mode and (b) explored gender differences in the predictors of perceived risk. Data were analysed from 595 driver licence holders in Australia: 444 who cycled regularly, termed ‘cyclists’ from here on (31% women) and 151 regular drivers who did not (63% women), who are referred to as ‘drivers’. Cyclists in their role as cyclists and drivers in their role as drivers (traffic role) were instructed to imagine being in a specified traffic scenario and to assess crash likelihood. Each of 6 traffic scenarios was presented twice but differing in configuration: a violating car and a violating bicycle. A mixed ANOVA, with rated probability of a crash as the dependent variable, gender and traffic role as grouping factors, and configuration as the repeated measure, resulted in a main effect of configuration, showing that both drivers and cyclists perceived higher levels of risk of violating cars than of violating bicycles (η_p2 = 0.34). The interaction of traffic role and configuration showed this difference to be smaller for drivers than for cyclists (η_p2 = 0.18). This suggests that drivers are aware of the car’s high injury potential in crashes with cyclists. The main effect of gender showed that irrespective of traffic role, women perceived higher risk than men, which supported the hypothesis that gender differences are not limited to cycling (η_p2 = 0.03). The main effect of traffic role was not significant.For the predictors of perceived risk, ANOVA showed main effects for traffic role and gender, with small effect sizes (from η_p2 = 0.02 to η_p2 = 0.03). Cyclists were more confident, less inattentive and more in favour of stricter laws. Women felt less skilled and were more concerned about risks. None of the interactions between gender and traffic role were significant, which lent further support to the hypothesis that gender differences were a general rather than a cycling specific characteristic. Thus, perceived risk does not differ between women who regularly cycle and those who do not. These findings may inform interventions about the role of perceived risk in the uptake of cycling.     

Effects of personality on driving behaviors among professional truck drivers: The mediating effect of safety climate

Introduction: The number of traffic accidents involving truck drivers remains high, and strategies to eliminate the probability of such accidents have been proposed, among which enhancing the safety climate has attracted much interest. The main purpose of the current study was to validate the Chinese version of the safety climate scale for truck drivers and apply it to investigate the mediating effect of safety climate between truck driver personality and driving behavior. Method: A total of 389 male truck drivers completed the Big Five Inventory, the Chinese version of the trucking safety climate scale, the driver behavior questionnaire and the positive driver behavior scale. Results: The reliability and validity of the Chinese version of the organization-level safety climate scale and the group-level safety climate scale were confirmed through factor analysis. More importantly, a path analysis revealed that the organization-level safety climate mediated the effects of agreeableness and neuroticism on aggressive violations, ordinary violations and lapses, while the group-level safety climate mediated the influences of agreeableness, neuroticism and openness on positive behavior and all four kinds of aberrant driving behaviors. Conclusions: This study introduced the trucking safety climate scale into China and stressed the significance of improving both the organizational and the group levels of safety climate to reduce accidents involving professional truck drivers. Practical Applications: First, the adapted safety climate scale for Chinese truck drivers contributes to further investigating the role that safety climate plays in the safety problem of truck drivers in China. Moreover, the critical impacts of both levels of the trucking safety climate serve as reminders for relevant companies to not only pay attention to establishing an organization-level safety climate but also invest more effort into promoting the group-level safety climate.     

The role of executive function,personality and attitudes to risks in explaining self-reported driving behaviour in adolescent and adult male drivers

Young drivers show high levels of risky driving and are over-represented in motor vehicle crash statistics world-wide. As well as personality and attitudinal factors, high rates of risk taking during adolescence may be due to poorly developed executive functions, a result of the slow maturation of the pre-frontal cortex of the brain. This study was undertaken to investigate the roles of executive function, personality, attitudes to risk in relation to self-reported driving behaviour. Adolescent (n = 46, age 16–18 years) and adult (n = 32, 25 years and over) male drivers completed a battery of neuropsychological tests to assess general cognitive ability and executive function, and questionnaires to assess driving history, personality, attitudes to physical and psychological risk as well as questionnaires of self-reported driving behaviour (Driver risk taking and Driver Attitude Questionnaire, DAQ). The adolescent drivers showed poorer executive function, higher levels of impulsivity and risk-taking, lower levels of agreeableness and conscientiousness compared to adult drivers. Regression analyses revealed that attitudes to risk, agreeableness and working memory made unique significant contributions in explaining self-reported driving behaviour. Interestingly though, better working memory was associated with higher levels of self-reported risky driving and more accepting attitudes to risky driving. Together the findings suggest that some aspects of executive function, personality, and attitudes to risk may help to explain self-reported driving behaviour. Whether these findings are relevant to female drivers and apply to on-road driving behaviour should be the focus of future studies.     

Working on a cognitive task does not influence performance in a physical fitness test

PurposeA limited number of studies have looked at the negative effect that cognitive fatigue has on physical performance.Methods and resultsTwo studies were conducted to assess the impact of a cognitive task on performance in an externally paced running task. In study 1, 12 trained athletes completed a standardized shuttle run, once after a cognitively fatiguing task (unmatched stroop for 10 min) and once after an easy cognitive task (matched stroop for 10 min). Performance in the shuttle run test did not differ between the two conditions, and, surprisingly, perceived effort was significantly higher in the control condition. In study 2, the control condition was modified and the easy cognitive task replaced by watching a video. 11 trained athletes completed both sessions, however, there were again no differences in either performance or in perceived effort.ConclusionBoth studies failed to reveal an impact of cognitive fatigue on subsequent physical performance. These findings contribute to the growing body of literature in this area, showing that the relationship between cognitive and physical task completion is not straightforward, and that other important factors still remain for investigation.     

Duration discrimination in the context of age,sex, and cognition

It has been proposed that the perception of very short duration is governed by sensory mechanisms, whereas the perception of longer duration depends on cognitive capacities. Four duration discrimination tasks (modalities: visual, auditory; base duration: 100 ms, 1000 ms) were used to study the relation between time perception, age, sex, and cognitive abilities (alertness, visual and verbal working memory, general fluid reasoning) in 100 subjects aged between 21 and 84 years. Temporal acuity was higher (Weber fractions are lower) for longer stimuli and for the auditory modality. Age was related to the visual 100 ms condition only, with lower temporal acuity in elder participants. Alertness was significantly related to auditory and visual Weber fractions for shorter stimuli only. Additionally, visual working memory was a significant predictor for shorter visual stimuli. These results indicate that alertness, but also working memory, are associated with temporal discrimination of very brief duration.     

Dimensions of fatigue in different working populations

Perceived fatigue related to work has often been measured in one dimension. The main purpose of the present study was to validate a proposed five-factor model of perceived fatigue in a new sample. 597 persons, employed in five occupations with different types of work loads, rated their fatigue after work. The ratings were subjected to analyses of linear structural equation models. The results suggest a slightly revised model for perceived fatigue, still with the five dimensions: Lack of energy, Physical exertion, Physical discomfort, Lack of motivation and Sleepiness. As expected, the rating profiles describing fatigue states differed between the five occupations. On the basis of these results, a revised version of the Swedish Occupational Fatigue Inventory (SOFI) is presented.     

Perceived job autonomy and turnover intention: The moderating role of perceived supervisor support

Perceived job autonomy has been recognized as a central tenet of work design, leading to a range of positive outcomes. Still, scholars have rightfully questioned its predictive role for several outcomes, including turnover intention as the two have been found to be virtually unrelated. In line with calls for more complex research on the predictive role of perceived job autonomy on employee outcomes, the purpose of this study was to investigate whether the relationship between perceived job autonomy and turnover intention may be prone to contextual influences. Two cross-sectional surveys among 680 Norwegian employees from different public service organizations showed that the relationship between perceived job autonomy and turnover intention was moderated by perceived supervisor support. In support of our hypothesis, the form of the moderations revealed that perceived job autonomy was negatively related to turnover intention only for employees reporting high levels of perceived supervisor support. Implications for practice and directions for future research are discussed.