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.     

Electrocortical Responses to ecologically relevant visual stimuli among professional drivers with and without cardiovascular disease

Electrocortical responses were assessed using two simulated aspects of visual signals encountered in traffic: the Glare Pressor Test (GPT) and Event-Related Potential Avoidance Task (ERPAT) among four groups of male professional drivers: 12 with ischemic heart disease (IHD), 12 hypertensives, 10 borderline hypertensives, 34 who were apparently healthy and 23 nonprofessional driver healthy control subjects. The blood pressure (BP) responses immediately after the ERPAT were also measured. There was a significant between groups effect for the amplitude of the target N2 component in the ERPAT (p=0.02), with the lowest means among the drivers with IHD and the highest among those with hypertension. Drivers with IHD also showed the highest diastolic BP reactivity to the ERPAT. Significantly more than the expected number of drivers with IHD failed to recover alpha activity after the first glare impulse of the GPT. Professional drivers who failed to recover baseline levels of alpha activity after the GPT showed a significantly smaller N2 amplitude compared to those who recovered (p=0.01). There was a positive correlation between abundance of alpha activity at rest with P300 amplitude (p=0.02). An inverse relation was found between number of work hours behind the wheel and the amplitude of the target P300 (p=0.04). Results are interpreted in light of recent advances concerning integrative mechanisms of defence versus vigilance response patterns. The findings in this study justify further applications of these psychophysiologic methods to assess the relationship between simulated signals of the work environment and mechanisms of cardiac risk in this occupational group.     

The effect of sleep-need and time-on-task on driver fatigue

Both sleep- and task-related factors are thought to contribute to driver fatigue, with each factor individually associated with deteriorated driving performance. However, the relative and combined effects of these factors in the context of monotonous driving have not been well studied. This study (N = 60) investigated lateral and longitudinal vehicle control, subjective fatigue and physiological response (EEG) during three 10-minute periods of time-on-task spread across a monotonous, 2-hour simulator drive. Level of physiological sleep-need was manipulated between participants by varying the instructed time spent in bed on the night before testing (≤5h or ≥ 8 h). In addition, half of the participants in each sleep group read the applicable speed limit from periodic roadside signs whereas the others performed an arithmetic calculation, displayed on the signs, to determine the speed limit. This task manipulation has been demonstrated to reduce performance decrements over time. Results demonstrated effects of time-on-task and sleep need on self-report ratings, an effect of time-on-task on EEG indices, and an interaction of sleep-need and time-on-task on an EEG index of mental workload and on the lateral control measure of driving performance. There were no significant effects on the measure of speed variability. These results confirm that both sleep-need and time-on-task negatively affect driver state, and that time-on-task decrements in driver performance can occur in the absence of heightened sleep-need. Results also suggest that drivers with heightened sleep-need could protect their performance for a short time, perhaps by exerting effort to compensate for reduced capacity. The secondary task did not counteract declining performance.     

Analysis of the factors affecting drivers’ queue-jumping behaviors in China

In China, drivers’ queue-jumping behaviors are very common. To explore the factors affecting drivers’ queue-jumping, first, a driving attitude scale, a risk perception scale and a queue-jumping behavior scale were designed, and an existing Type A behavior pattern scale and a driver skill scale were also introduced. Second, these scales were used to collect empirical data, and 202 valid samples were obtained. Third, the reliability and validity of the developed scales were verified, and a structural equation model of drivers’ queue-jumping behaviors was established to explore the interrelationships among the Type A personality trait, cognitions (including attitudes and risk perception), driver skills (including driving skill and safety motivation) and queue-jumping behaviors. The results showed that drivers’ cognitions significantly affected their queue-jumping behaviors; specifically, drivers’ attitudes toward queue-jumping and traffic violations positively correlated with their queue-jumping behaviors (β = 0.323, t = 3.470; β = 0.277, t = 3.072), while drivers’ risk perception toward queue-jumping negatively correlated with their queue-jumping behaviors (β = −0.297, t = −3.889). Drivers’ driving skill and safety motivation also significantly affected their queue-jumping behaviors (β = 0.198, t = 2.385; β = −0.355, t = −4.101). Although Type A personality trait had no significant effects on drivers’ queue-jumping behaviors, it had significant effects on drivers’ attitudes toward queue-jumping and traffic violations (β = 0.336, t = 4.720; β = 0.215, t = 2.873) and their risk perceptions toward queue-jumping (β = −0.232, t = −3.279). In other words, the Type A personality trait can indirectly affect drivers’ queue-jumping behaviors through drivers’ attitudes and risk perceptions toward queue-jumping. The results provided offer traffic administration departments a theoretical foundation for governing this behavior.     

卡车驾驶员的夜间视力研究

运用ＹＪＳ—ＩＩ型夜间视觉检查仪对２３８名男性卡车驾驶员的暗适应时间和夜间视力进行了测试。结果表明：卡车驾驶员暗适应时间的９５％上限值为５９．６７秒;卡车驾驶员暗适应时间和夜间视力的年龄阈值为４０岁;事故组与安全组卡车驾驶员暗适应时间存在显著差异（Ｐ＜０．０５）,事故组卡车驾驶员的暗适应时间较长,表明卡车驾驶员的暗适应能力差是引起夜间交通事故的重要因素。研究结果为驾驶员的选拔,安全教育以及制订预防夜间交通事放对策提供一定的理论依据。     

The differences in hazard response time and driving styles of violation-involved and violation-free taxi drivers

The present study aimed to investigate the relationships between taxi drivers’ traffic violations in past driving and two domains: driving skill (hazard perception skill) and driving style. Five hundred and fifty taxi drivers aged 25 – 59 were recruited to finish a video-based hazard perception test and the Chinese version of the Multidimensional Driving Style Inventory (MDSI). The relationships between hazard response time, driving style and traffic violations were examined, and the differences in hazard response times and driving styles of violation-involved drivers (n = 220) and violation-free drivers (n = 330) were compared. The results showed that taxi drivers’ traffic violations are closely related to their driving styles and hazard response time. Violation-involved drivers scored significantly higher in hazard response time and maladaptive driving styles (i.e., anxious, risky and angry styles) and lower in careful driving style than violation-free drivers. More importantly, drivers’ hazard response time and driving styles can effectively predict their violation involvement in the last 12 months with an overall classification accuracy of 66.4%. The findings provide evidence for the usefulness of video-based hazard perception tests and the MDSI in taxi driver testing and training.     

Driver behaviour and traffic accident involvement among professional urban bus drivers in China

The present research aimed to investigate specific behaviors of professional urban bus drivers in China with the revised Driver Behavior Questionnaire (DBQ), and to define the relationships among various driving behaviors (errors, positives, inattention errors, violations), background information (age, years of driving experience, mobility, etc.), self-assessment, and traffic accident. To achieve such goals, the present research designed a four-dimensional DBQ with 20 items for professional urban bus drivers in China. The KMO coefficient of the whole scale was 0.835, and Bartlett’s test was statistically significant (p < 0.000), which demonstrated strong validity of the scale and should be suitable for factor analysis. The four loading factors accounted for 58.991%. In addition, the reliability and effectiveness of the present 20-item scales were measured. The coefficient of internal consistency-Cronbach’s alpha coefficient was 0.881 and the Cronbach’s Alpha Based on Standardized Items was 0.911. This showed that driving behavior scale of professional bus drivers in China was of high reliability and validity. The analysis showed that among the four factors, positive driving behaviors were significantly associated with errors, inattention errors and violations, respectively. Errors, inattention errors and violations correlated positively with each other. This verified that the correlation coefficient of each factor was medium and high, which indicated that the scale had good difference validity. The test content of the total scale was also highly consistent with the test content of each factor, which indicated that the revised scale had good standard related validity. According to the accident prediction model, the variables that significantly affected the occurrence of traffic accidents were daily driving time, positive driving behavior, SE2 (Driving safety), SE3 (Aberrant driver behaviors). The results showed that professional bus drivers often working overtime were most likely to have accidents. The probability of traffic accidents decreased by 53% for every unit of positive driving behavior frequency of professional bus drivers. The more they felt that they had the tendency of aberrant driving behavior, the more likely they were to have traffic accidents. To summary, the present research contributed to validating and improving the DBQ for professional urban drivers in China.     

Exploring the effects of EEG signals on collision cases happening in the process of young drivers’ braking

Detecting mental states in drivers offers an opportunity to reduce accidents by triggering alerts and signaling the need for rest or renewed focus. Here we used electroencephalography (EEG) to measure brain signals in young drivers operating a driving simulator to detect mental states and predict accidents. We measured reaction times to unexpected hazardous events and correlated them with EEG signals measured from the frontal, parietal, and temporal cortices as well as the central sulcus (corresponding to motor cortex). We found that EEG signals in the relative beta (power in beta (13–30 Hz) relative to total power of the EEG (0.5–30 Hz)), alpha/delta, alpha/theta, beta/delta, beta/theta frequency bands were higher for collisions than successful collision avoidance, and that the key decision-making period is the 2nd second before braking. Importantly, a decision tree classifier trained on these neural signals predicted collision avoidance outcomes. Then based on random forest model, we extracted three critical neural signals (beta/delta_frontal, relative beta_parietal and relative beta_central Sulcus) to classify collision avoidance outcomes. Our findings suggest measuring EEG during driving may provide useful signals for enhancing driver safety.     

Transcultural validation and reliability of the Spanish version of the behaviour of young novice drivers scale (BYNDS) in a Colombian young driver population

The overrepresentation of young drivers in road crashes, and the fatalities and injuries arising from those crashes, is an intractable problem around the world. A plethora of research has led to the development and application of a range of research tools, including self-report survey instruments. One such instrument, the five-factor Behaviour of Young Novice Driver Scale (BYNDS), was developed in an Australian young driver population, and has recently been validated in a New Zealand young driver population. The current study aimed to validate the BYNDS in a Colombian young driver population, the first application of the instrument in a developing country. Translation from English to Spanish, and back translation from Spanish to English, in addition to culturally-appropriate modifications (such as changing ‘right hand side’ to ‘left hand side’) resulted in a Spanish version of the BYNDS (BYNDS-Sp). The BYNDS-Sp was administered to a sample of 392 young drivers aged 16–24 years (n = 353 aged 19–24 years) with a valid driver’s licence. An exploratory factor analysis revealed a six factor structure using 40 of the original 44 BYNDS-Sp items, accounting for 58.5% of the variance in self-reported risky driving behaviour. Ninety-three percent of participants reported having ready access to their own vehicle (42% owned their own vehicle), with Colombian young drivers most likely to report driving at night and on the weekend. The majority of participants reported driving in excess of posted speed limits (e.g., only one third of participants reported never driving 10–20 km/h over the speed limit), and driving in response to their mood (e.g., only one third of participants reported they never drove faster if in a bad mood). As such, the BYNDS-Sp can reveal patterns of problematic behaviours (such as risky driving exposure), in addition to specific behaviours of concern (such as carrying passengers at night, and driving when tired), guiding the development and implementation of interventions targeting the risky driving behaviour of young drivers in Colombia. In addition, the BYNDS-Sp can be used as a measure of intervention success if used as a baseline and as a follow-up tool. Further research can investigate the utility and applicability of the BYNDS-Sp in other Spanish-speaking countries, such as Spain and Mexico.     

A comprehensive analysis of factors leading to speeding offenses among large-truck drivers

Much research has demonstrated that speeding is the most common offense among car drivers. However, few studies have focused on this offense among drivers of large trucks. This paper investigates the factors that lead to speeding offenses for drivers of large trucks in Taiwan. The study sample consisted of information for 2101 male large-truck drivers from a national survey in 2012. The results revealed that drivers’ daily working hours ranged from 2 to 15 h with a mean of 9.67 h, and that they worked for approximately 25.23 days – and rested only 4.77 days – per month. Among these observed drivers, 11.6% reported having at least one speeding offense over a one-year period. The results of a logistic regression model presented that the factors that influenced speeding offense were not related to job experience. Rather, the driver’s demographics (age and education), mental condition (sleep quality), and driving status (yearly distance driven and driving late at night) were significantly linked to speeding offenses.     

Young drivers’ perception of hazards: Variation with experience and day versus night

Young novice drivers have a relatively high crash risk for several years following initial licensing, and while all drivers are at greater risk at night, the night-time increase is greater for inexperienced drivers. Poor hazard perception has been identified as an important contributor to inexperienced drivers’ risk, but research on day-night differences in hazard perception for drivers varying in experience is lacking. This exploratory study investigated the nature of hazards reported by young inexperienced drivers versus more experienced and slightly older drivers. Hazards were not pre-identified by researchers; participants were simply provided with a general definition of ‘hazard’. Analysis focused on how experience level affected qualitative differences in the kinds of hazards reported, with particular focus on day-night differences.The 53 participants ranged in driving experience from learners through to 5+years post licensing, and in age from 16 to 30 years. They viewed 14 day- and night-time video clips of a diverse range of driving situations, pausing the video whenever they identified a hazard and then explaining why they had paused it at that point. Their responses were recorded. Content analysis of responses showed that more experienced drivers reported visibility-related hazards significantly more often than inexperienced ones, and significantly more so at night. They also commented significantly more on hazards related to tight bends in the road and significantly less on hazards concerning compliance with rules. Comments tended to be fewer with higher vehicle speeds, particularly for the least experienced drivers.Results are discussed in terms of how experience-related differences in drivers’ cognitive schemata and mental models are likely to affect hazard perception and crash risk, particularly at night. Some implications for driver training and license testing are suggested.     

The relationship between leisure time and driving style in two groups of male drivers

Despite overall improvements in traffic safety levels, young male drivers continue to be over represented in accidents. In this study the association between driving style and leisure time was examined in two groups of drivers. The sample consisted of 4000 male drivers of which 2000 were 18 years old and 2000 were 28 years old. A posted questionnaire was used. The overall response rate was 51% (N = 2018). A similar factor structure of three factors with regard to driving style was identified in both groups of drivers. The factors were named Thrill, Anxiety and Anger. Despite significant differences regarding specific leisure time activities, a similar relationship between leisure time and driving style was found in the two groups of drivers particularly in relation to problem behaviours. In both groups driving related interaction with friends as well as a high paced leisure time was found to be related to a high score on the factors Thrill and Anger. In the older group of drivers cruising with friends was associated with problem behaviours such as smoking pot and doing drugs. Results indicate a need for early intervention enhancing safe behavioural choices thereby preventing unsafe behaviours to become permanent behavioural strategies in life.     

Perceived risk vs actual driving performance during distracted driving: A comparative analysis of phone use and other secondary distractions

The present study attempts to explore the association of drivers’ risk perception towards phone usage as well as other everyday distractions (operating a music player and eating during driving), and their driving performance observed during these distracted conditions. For this purpose, driving simulator experiments were conducted with 90 participants to collect their driving performance data and a questionnaire was conducted to obtain their basic details along with their risk perceptions. Firstly, the driving performance was divided into clusters using hierarchical clustering and the clustered subgroups were compared for crash and non-crash cases to identify the groups having significant performance degradation. Based on this comparison, the driving performance subgroups were then divided into the following crash risk probabilities: High risk, Moderate risk and Low risk. Further, the associations of perceived risk with these performance subgroups and other potential factors were analyzed using association rules mining technique. Most of the drivers (72.06%) reported texting as an extremely risky task. But, surprisingly none of them considered conversation as an extremely risky task. However, in case of conversation, it was found that even though the professional drivers reported the task to be not at all risky, the observed crash risk was high for them (S = 5.21%, C = 67.86%), indicating an underestimation of the associated risk by the drivers. Similarly, the results revealed that for music player and eating tasks, drivers reported the distracting tasks to be less risky, but, in some instances, their driving performance was associated with higher chances of crash occurrence. Many interesting associations of risk perception and driving performance with respect to demographic and driving characteristics were also obtained. The findings can be useful while designing the awareness programs related to distracted driving with an aim to reduce such practices.     

Personality and demographic differences in the perceived risks of potentially timid driving behaviours

Timid driving behaviours can be described as overly cautious and hesitant driving behaviours. Little research has examined behaviours that potentially resemble timid driving and how these behaviours are perceived by other drivers. This is despite the potential for these behaviours to be perceived in a way that leads to angry and aggressive retaliatory behaviours in some drivers (e.g., in anger-prone drivers). We conducted an online survey examining the perceived road safety risks of several behaviours that could potentially result from timid driving and their relationships with driver personality (trait anxiety, trait driving anger), behaviour (anxious driving, angry driving), and demographic (age, gender, annual mileage) background. Drivers (N = 439, M_age = 49.41 ± 5.59 years, aged 18–89) perceived excessively cautious and unpredictable braking behaviours as posing moderate levels of risk. Multiple linear regression analyses also indicated higher perceived risks of slow and excessively cautious behaviours in older, male, and anger prone drivers. No meaningful associations were found between driver characteristics and the risks of unpredictable braking behaviours. These results suggest that safety campaigns to reduce aggressive behaviour may benefit from targeting the perceptions of other drivers’ behaviours.     

Understanding and modelling risky driving behaviour on high-speed corridors

This study explores the relationships among various factors influencing risky driving behaviours, particularly on high-speed corridors (expressways). A total of 546 samples are collected from licenced drivers through an online survey. Exploratory factor analysis confirms the four-factor solution and the same is verified using confirmatory factor analysis. These factors are individual aberrant driving behaviour (violations and errors), risky driving behaviour performed by surrounding vehicles and dangerous manoeuvres due to prevailing road environment. Structural equation modelling is used to establish the relationships amongst the aforementioned factors. The results of the study describe that observed risky driving behaviour on expressways is mostly affected by drivers’ individual aberrant driving (γ = 0.62) followed by risky driving behaviour performed by surrounding vehicles (γ = 0.39) and least affected by the road environment (γ = 0.36). The individual driving behaviour is mostly affected by violations (γ = 0.47) followed by errors (γ = 0.38). Furthermore, differences in Driving Behaviour Questionnaire (DBQ) scales are analysed with respect to the demographic variables. Results suggest that male and young drivers report more violations than female and older drivers, respectively, however, female drivers are more error prone than male drivers. The findings of the study can be useful to identify the potential road safety countermeasures to improve the driving style as well as the driving environment.     

A matter of style? Testing the moderating effect of driving styles on the relationship between job strain and work-related crashes of professional drivers

Different empirical studies suggest that both job strain and driving styles are significant contributors to the work-related traffic crashes suffered by professional drivers. Nevertheless, the current evidence falls considerably short when explaining why driving styles may modify (or not) the relationship between occupational stressors and professional drivers’ safety outcomes. The aim of this study was to examine whether driving styles moderate the effect of job strain on professional drivers’ Work Traffic Crashes (WTCs). This research was performed using the data collected from a sample of 753 professional drivers, responding to a self-report questionnaire on job strain (work stress indicator of the Job Demand-Control model), driving styles and work-traffic safety outcomes suffered in the past two years. Regression-based moderation analyses suggest that the job strain of professional drivers is positively associated with the occupational traffic crashes they suffer, and that such association is stronger in drivers with “reckless & careless”, “anxious”, and “angry & hostile” driving styles. Meanwhile, the “patient & careful” (positive) driving style was not associated with a lower risk of suffering a WTC, nor with a lower vulnerability to stress-related WTCs. The results of this study support the hypothesis that driving styles exert a statistical moderation between the job strain and the occupational traffic crashes suffered by professional drivers. These findings may support the design of evidence-based interventions in both the organizational and individual levels, focused stress-related factors and driving styles as predictors of work traffic crashes.     

Driving distraction at night: The impact of cell phone use on driving behaviors among young drivers

Currently, young drivers are more likely than other drivers to use cell phones while driving at night, which has become a major cause of road crashes. However, limited attention has been given to distracted nighttime driving. Therefore, the aim of this study was to explore the interaction effect of cell phone use and time of day (daytime and nighttime) on young drivers’ car-following performance. Forty-three young drivers engaged in a driving simulator experiment with a within-subject design that included three distractions (no distraction, talking and texting on a cell phone) and two times of day. This paper applied non-parametric tests to analyze the data and obtained the following results: (1) the standard deviation of lane position (SDLP) did not significantly differ at either time of day under no distraction, but it was significantly higher at night on straight roads and large-radius curves after introducing distractions. In addition, participants drove faster and gave less headway on small-radius curves under both distractions at night; (2) texting significantly increased the SDLP, while there was less lateral variation during the talking tasks than under no distraction on simple road sections; and (3) compared with the experienced drivers, the novice drivers drove faster during the talking tasks on small-radius curves, but there was no significant difference between groups during the texting tasks. These findings provide both theoretical and practical implications for related policy makers to enhance traffic safety.     

Contextual Design for driving: Developing a trip-planning tool for older adults

Independent living depends on mobility, and mobility depends on driving, particularly for people 65 years and older. The longer older adults can safely drive, the longer they can independently run errands, shop, exercise, and maintain social networks. Age-related decline of perceptual, motor, and cognitive abilities can undermine the mobility and driving safety of older drivers. Data from driving simulators, on-road tests, surveys, and crash reports describe the driving safety and mobility challenges of older adults, but these methods offer a limited view of these challenges and fail to indicate design solutions. Contextual Design—a combination of Contextual Inquiry interviews, model building, and affinity diagrams—offers a complementary approach to uncover challenges that older adult drivers’ experience. For two weeks, 39 drivers age 65 and above, had their vehicles instrumented to collect driving and video data. Applying Contextual Design to these data showed that older drivers in urban and rural settings faced different mobility challenges and adopted various strategies to mitigate risk: older drivers often involved their spouse or passenger in the driving task, avoided certain driving maneuvers such as left turns, avoided unfamiliar or poorly lit roads at night, and planned trips to avoid risky driving situations. Ridesharing and trip planning emerged as important strategies to improve the safety and mobility of older drivers. Ridesharing could serve as a potential solution to prolong mobility; however, factors such as wait time, scheduling conflicts, costs, and trust were concerns for older drivers. A paper prototype was developed to validate the driving challenges faced by older drivers, and guide the development of a customized web-based trip-planning tool. The trip-planning tool could help older drivers make safer route choices by offering routes with fewer driving challenges, thereby enhancing their driving safety, mobility, and independence.     

A new approach to identifying the effect of diabetic peripheral neuropathy on the ability to drive safely

The purpose of this study was to estimate the potential for impaired driving performance in current drivers with diabetic peripheral neuropathy compared to healthy controls. We analysed, using a driving simulator, three important aspects of driving - use of the accelerator pedal, steering wheel and eye-steering coordination - to test for any differences, and then to integrate these findings to identify a unique pattern of changes in people driving with diabetic peripheral neuropathy. Patients with diabetic peripheral neuropathy displayed differences in use of the accelerator pedal compared to healthy control drivers (p < 0.05) which could be a direct consequence of their sensorimotor impairment due to diabetic peripheral neuropathy. Drivers with DPN used the more extreme high and low positions of the pedal to a greater extent than the Control group who exhibited a more graded use of the accelerator pedal over the mid-range. Eye-steering coordination was also different in drivers with diabetic peripheral neuropathy (p < 0.05) and, as it improved during the second drive, becoming closer to healthy drivers’ values, the occasional loss of control experienced during driving reduced. These insights demonstrate that diabetic peripheral neuropathy affects multiple aspects of driving performance suggesting the need for an integrated approach to evaluate the potential for driving safely in this population.