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.     

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.     

Lifestyle traits as predictors of driving behaviour in urban areas of Greece

The aim of this study was to examine possible links between different lifestyle patterns and aberrant driver’s behaviour. Personal interviews were conducted in a representative sample of 324 adults (18–65), all residents of Crete. Aberrant driver’s behaviour was assessed by the ‘driver behaviour questionnaire’ (DBQ). Also to measure different dimensions of lifestyle, first, a 26-items questionnaire was used, and second, three questions measuring ‘driving without destination’, related in previous findings with road accident risk. Four lifestyle patterns: ‘religion/tradition’, ‘driving aimlessly’, ‘sports’ and ‘culture’ are significant predictors of ordinary violations. ‘Driving without destination’ has a significant effect all three DBQ factors (b positive). ‘Religion/tradition’ was related only to ordinary violations (b negative) and ‘sports’ has a positive impact on ordinary violations and a negative impact on ‘errors’. Two lifestyle factors are related to more dangerous driving: ‘Driving without destination’ and/or pursuing a more ‘athletic way of living’. Road safety campaigns must teach the first group to use other hobbies and activities to vent their feelings and the second, not to overestimate their abilities, while driving.     

Judgments of mean speed and predictions of route choice

How are driving speeds integrated when speeds vary along a route? In a first study, we examined heuristic processes used in judgments of mean speed when the mean speeds on parts of the trip varied. The judgments deviated systematically from objective mean speeds because the distances driven at different speeds were given more weight than travel time spent on the different distances. The second study showed that when there was a 10–15 min pause during a travel the effect on the mean speed decrease was underestimated for driving speeds of 90 km/h and higher. In the third study, the objective mean speeds and the subjective biased mean speed judgments were used to predict choices between routes with different speed limits. The results showed that subjective judgments predicted decisions to maximize mean speed significantly better than objective mean speeds. Finally, some applied and basic research implications of the results were discussed.     

Bias in older adults’ driving self-assessments: The role of personality

A convenience sample of 50 older drivers (M_age = 73.14, SD = 4.85) completed the Myers-Briggs Type Indicator® (MBTI®) Step III™ instrument and rated their own driving abilities (compared to all other drivers, same age drivers, and their own driving 20 years prior) and their ability to perform 68 specific driving-related behaviors. Each subject’s driving performance was also evaluated in a comprehensive on-road assessment conducted by a certified driving rehabilitation specialist, who rated the same 68 driving behaviors as well as driving performance. Drivers identified by the MBTI Step III instrument as Extraverted, Sensing, and (above median) Confident rated their driving significantly more favorably than Introverts, Intuitives, and below median Confidence drivers. Step III Sufficiency scales were associated with on-road performance: drivers with scores indicating low Confidence, low Stamina, or critical high levels of Compensatory Strain received significantly lower evaluations. Drivers with a Sensing preference or critical Strain score rated their driving significantly more favorably than evaluators did. These findings present preliminary evidence for the utility of personality assessments in identifying self-serving bias in driving self-evaluations, essential for safe self-regulation of driving.     

Strategic adaptation to performance objectives in a dual-task setting

How do people interleave attention when multitasking? One dominant account is that the completion of a subtask serves as a cue to switch tasks. But what happens if switching solely at subtask boundaries led to poor performance? We report a study in which participants manually dialed a UK‐style telephone number while driving a simulated vehicle. If the driver were to exclusively return his or her attention to driving after completing a subtask (i.e., using the single break in the xxxxx‐xxxxxx representational structure of the number), then we would expect to see a relatively poor driving performance. In contrast, our results show that drivers choose to return attention to steering control before the natural subtask boundary. A computational modeling analysis shows that drivers had to adopt this strategy to meet the required performance objective of maintaining an acceptable lateral position in the road while dialing. Taken together these results support the idea that people can strategically control the allocation of attention in multitask settings to meet specific performance criteria.     

Testing for effects of racial attitudes and visual contrast on the speed of a driver’s response to a pedestrian

Although ethnic minorities are overrepresented in pedestrian-vehicle collisions, previous driving studies did not examine racial attitudes in such collisions. Our objective was to determine whether the speed of a driver’s response to a pedestrian was affected by the driver’s racial attitudes and the contrast between the pedestrian’s skin colour and background. Participants viewed simulated driving scenes of a pedestrian on a road and pressed a button as soon as they saw an obstacle. Visual information, but not racial attitudes, affected the time it took observers to respond to pedestrian and non-pedestrian stimuli in driving scenes. Results indicated that contrast affected response time even when the stimulus was subliminal. We believe this is the first demonstration of contrast effects with subliminal stimuli in a driving context. Results have implications for traffic safety and for methodology used to study racial attitudes.     

Functional Consequences of HIV-Associated Neuropsychological Impairment

This review focuses on the “real world” implications of infection with HIV/AIDS from a neuropsychological perspective. Relevant literature is reviewed which examines the relationships between HIV-associated neuropsychological impairment and employment, driving, medication adherence, mood, fatigue, and interpersonal functioning. Specifically, the relative contributions of medical, cognitive, psychosocial, and psychiatric issues on whether someone with HIV/AIDS will be able to return to work, adhere to a complicated medication regimen, or safely drive a vehicle will be discussed. Methodological issues that arise in the context of measuring medication adherence or driving capacity are also explored. Finally, the impact of HIV/AIDS on mood state, fatigue, and interpersonal relationships are addressed, with particular emphasis on how these variables interact with cognition and independent functioning. The purpose of this review is to integrate neuropsychological findings with their real world correlates of functional behavior in the HIV/AIDS population.     

Effects of visual roll on steering control and gaze behavior in a motorcycle simulator

The goal of this study was to examine the effects of visual roll tilt on gaze and riding behavior when negotiating a bend using a motorcycle simulator. To this end, experienced motorcyclists rode along a track with a series of right and left turns whilst the degree of visual roll tilt was manipulated in three different conditions. Gaze behavior was analyzed by using the tangent point as a dynamic spatial reference; the deviation of gaze to this particular point was computed in both the horizontal and vertical directions. Steering control was assessed in terms of the lateral positioning, steering stability and number of lane departures. In the no-roll condition, the motorcyclists tracked a steering point on the road ahead, which was compatible with the hypothesis of “steer where you look” behavior. In the roll condition, our results revealed that the horizontal distribution of gaze points relative to the tangent point was preserved. However, significantly more fixations were made further ahead of the tangent point in the vertical direction. This modification of visual behavior was coupled with a degradation in steering stability and an offset in lateral positioning, which sometimes led to lane departures. These results are discussed with regard to models of visual control of steering for bend negotiation.