The effect of fatigue driving on car following behavior

Existing fatigued driving analysis methods mainly focus on lateral driving performance by using the measurements related to the steering wheel or lane position. There is a lack of research on longitudinal car following behavior. In this study, 40 professional drivers are invited to participate in field expressway driving experiment, lasting at least for 6 h. During the test, their performance is measured in terms of their self-reported fatigued driving level according to the Karolinska Sleepiness Scale (KSS), the PERcentage of eye CLOSures (PERCLOS) and the Time Headway (THW). Then the effects of the fatigued driving level on car following behavior are evaluated. The results indicate that the fatigue level (for both KSS and PERCLOS) has significantly impact on THW parameters, including the mean, standard deviation and minimum THW. An increase in KSS and PERCLOS leads to a lower mean and minimum THW. Meanwhile, the standard deviation of THW increases with the increase of KSS and PERCLOS. In conclusion, this study found that a higher fatigue level leads to the driver keeping a smaller THW when following another vehicle and choosing shorter THW to make lane change. More deviation of car following performance was also found with the increase of fatigue level. Therefore, the findings of this study can be used to explain fatigue as one of the major reasons for rear-end collisions. Also, the research findings demonstrate the impact of fatigue on driving behavior in terms of car following performance, which can be used as a measurement for monitoring fatigued drivers.     

The impact of safety climate on safety related driving behaviors

This study explored the impact of safety climate, age and tenure as a driver on safety related driving behaviors among 290 company drivers in Ghana. The study found a negative relationship between safety climate and studied work-related behaviors: speeding, rule violation, inattention and driving whiles tired. The study also found that age significantly predicted the extent to which drivers engaged in safety related driving behaviors. The results showed that young drivers (aged 20–35 years) engage more in risky driving behaviors relative to adult drivers (aged 36–60 years). The study also found that the tenure of a driver did not significantly affect work-related driver behaviors. The findings from this study suggests that in the quest to reduce safety related traffic accidents and its resulting consequences such as injuries, absenteeism and deaths, a critical organizational variable that organizations can use to mitigate this canker is commitment to and strict adherence to safety practices and regulations. By extension, the findings suggest, Ghana’s commitment to safety practices and enforcement of safety regulations and policies among others can help the country win the battle against road accidents.     

Testing the Bivalent Fear of Evaluation Model of Social Anxiety: The Relationship between Fear of Positive Evaluation,Social Anxiety,and Perfectionism

The Bivalent Fear of Evaluation (BFOE) model of social anxiety proposes that fear of negative evaluation (FNE) and fear of positive evaluation (FPE) play distinct roles in social anxiety. Research is however lacking in terms of how FPE is related to perfectionism and how these constructs interact to predict social anxiety. Participants were 382 individuals from the general community and included an oversampling of individuals with social anxiety. Measures of FPE, FNE, perfectionism, and social anxiety were administered. Results were mostly consistent with the predictions made by the BFOE model and showed that accounting for confounding variables, FPE correlated negatively with high standards but positively with maladaptive perfectionism. FNE was also positively correlated with maladaptive perfectionism, but there was no significant relationship between FNE and high standards. Also consistent with BFOE model, both FNE and FPE significantly moderated the relationship between maladaptive perfectionism and social anxiety with the relationship strengthened at high levels of FPE and FNE. These findings provide additional support for the BFOE model and implications are discussed.     

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.     

Are situation awareness and decision-making in driving totally conscious processes? Results of a hazard prediction task

Detecting danger in the driving environment is an indispensable task to guarantee safety which depends on the driver’s ability to predict upcoming hazards. But does correct prediction lead to an appropriate response? This study advances hazard perception research by investigating the link between successful prediction and response selection. Three groups of drivers (learners, novices and experienced drivers) were recruited, with novice and experienced drivers further split into offender and non-offender groups. Specifically, this works aims to develop an improved Spanish Hazard Prediction Test and to explore the differences in Situation Awareness, (SA: perception, comprehension and prediction) and Decision-Making (DM) among learners, younger inexperienced and experienced drivers and between driving offenders and non-offenders. The contribution of the current work is not only theoretical; the Hazard Prediction Test is also a valid way to test Hazard Perception. The test, as well as being useful as part of the test for a driving license, could also serve a purpose in the renewal of licenses after a ban or as a way of training drivers. A sample of 121 participants watched a series of driving video clips that ended with a sudden occlusion prior to a hazard. They then answered questions to assess their SA (“What is the hazard?” “Where is it located?” “What happens next?”) and DM (“What would you do in this situation?”). This alternative to the Hazard Perception Test demonstrates a satisfactory internal consistency (Alpha = 0.750), with eleven videos achieving discrimination indices above 0.30. Learners performed significantly worse than experienced drivers when required to identify and locate the hazard. Interestingly, drivers were more accurate in answering the DM question than questions regarding SA, suggesting that drivers can choose an appropriate response manoeuvre without a totally conscious knowledge of the exact hazard.     

Driver brake vs. steer response to sudden forward collision scenario in manual and automated driving modes

In autonomous vehicle operation, situations may arise when the driver is required to re-engage in manual control of the vehicle. Whether the control handoff from vehicle to human is done in a structured or unstructured manner, the process may be affected by the driver’s state, i.e. distracted or not. The study reported here was designed to measure a non-distracted driver’s response to a sudden forward collision (FC) event, in which the driver would assume manual control of the autonomous vehicle. Three driving scenarios were investigated: autonomous vehicle driven with full collision avoidance support, autonomous vehicle driven without collision avoidance support, and vehicle driven in manual mode.Forty-eight volunteers participated in a simulator study conducted in VIRTTEX. It was found that, at handoff, (1) drivers in manual mode tended to use evasive steering, rather than braking, compared to drivers in both the autonomous modes, (2) between subjects variations in speed were higher for the automation with collision support condition than for the other two scenarios, (3) for both autonomous driving scenarios, drivers reaction times were longer than for manual driving. In some cases the driver response was so late and the distance remaining so reduced that crash avoidance might be unfeasible. At a minimum, results of this study suggest that drivers may benefit from appropriate driver assistance technologies when a crash imminent situation is suddenly encountered.     

Measuring driving workload of heavy vehicles at roundabouts

Correctly designed roundabouts proved to have positive safety and functional performances. However, they are also affected by peculiar disadvantages. In particular, they are difficult to manoeuvre, especially for heavy vehicle drivers. Despite these concerns, there are currently no driving workload metrics devoted to roundabouts.A novel methodological approach is proposed for trying to quantify workload impinging on heavy vehicle drivers when manoeuvring through complex at-grade intersections. Proper acquisition of input data constitutes the starting point for future research about ascertainment of workload for these particular road scenarios. The described procedure enables recording steering wheel angles performed by a driver when manoeuvring an articulated lorry through a complex at-grade intersection. A field trial was carried out for verifying the practical feasibility of proposed method in capturing driver’s steering behaviour. Dynamic data acquired via global navigation satellite system instrumentation were related to actual driver’s steering wheel behaviour captured by camera frames. As a complement to the experiment, selected steering behaviour metrics were calculated. Steering Entropy attributed a high difficulty level to the manoeuvres performed through the roundabout, whereas High Frequency Component and Steering Reversal Rate showed intensity and occurrences of driver’s corrections needed for controlling position of the semitrailer at the ring. It appears that even a single roundabout may represent an arduous task for drivers. The study concludes with recommendations for further research about workload imposed by roundabouts to heavy vehicle drivers, with special attention to successions of closely spaced roundabouts.