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No description available.

Driver fatigue is a complex phenomenon that has a range of causal factors including sleeprelated and task-related factors. These manifest as different safety and performance outcomes. Extensive research has been applied to linking these factors to performance impairment. However, little research focuses on the mechanisms by which this link exists. This research project therefore focuses on the processes underlying how driving performance is controlled and maintained during the development on non-sleep-related driver fatigue. The main aim was to establish whether progressive impairment of driving control over a prolonged drive could be attributed to a depletion of attentional resources, as proposed by Resource Theory, or to a withdrawal of effort, as proposed by Effort-Regulation Theory. As a multicomponent skill, driving requires perception, cognition and motor output. The secondary aim of this research was therefore to assess whether a prolonged drive impairs stage-specific information processing. Participants (n=24) in three experimental groups performed a 90-minute simulated drive wherein they were expected to keep the bonnet of a car on a lane (tracking task). The three groups differed in terms of lane width: small, medium and large, corresponding to low, medium, and high task-demand, respectively. To assess the impacts of this task on stagespecific information processing, participants performed a set of resource specific tests before and after the prolonged drive. Each task had two difficulty variations to ensure that performance decrement was due not only to the task-characteristic, but specifically to resource depletion. The tests probing information processing were: a modified Fitts' tapping task for motor programming, a digit recall task for perception, and an object recognition reading task for cognition. Performance was measured as lateral deviation of the car. Physiological measures included heart rate frequency (HR) and various time- and frequencydomain heart rate variability (HRV) parameters, eye blink frequency and duration. The Borg CR-10 scale was used to evaluate subjective effort and fatigue during the task. Driving control declined over time and was supplemented by HR, HRV, blink frequency and duration, indicating an increase in parasympathetic activity (or a reduction in arousal). An increase in blink frequency was considered as a sign of withdrawal of attentional resources over time. Driving control declined to a greater extent in the large road width group and reflected a lower parasympathetic activity, whereas the inverse was observed for the small road width group. Resource tests reveal a non-specific impairment of information processing following the prolonged drive. However, this was accompanied by an increase in parasympathetic activity. Overall, results indicate that Effort-Regulation Theory better accounts for the impairment of driving control in prolonged driving than does Resource Theory. This suggests that the impact of fatigue is guided more by task goals and intrinsic motivation than by the manner in which the fatigue state developed. Moreover, performance impairment by effort-regulation is dependant more on time on task than on task-demand

Worldwide, motor accidents are responsible for a large number of deaths and disabilities (Connor et al., 2001), and one of the major causes of motor accidents is driver fatigue. Although majority of drivers are aware of the dangers of fatigued driving, accidents related to this continues to contribute to a large percentage of all accidents, between 5 and 50% (Nilsson et al., 1997; Williamson et al., 2011). The purpose of the research was to establish the effect that fatigue renders on an individual’s peripheral visual field and to determine whether a decrement in driving performance occurs at the same rate as a decrement in peripheral visual performance. Fatigue was induced through time of day as well as time on task. Sixteen students from Rhodes University were recruited, subject to no previous sleep disorders, among other criteria. Each participant was required to partake in two conditions, namely a day condition (09h00–11h00) and a night condition (23h00– 01h00). Each condition consisted of a 90 minute dual task; the primary task was a tracking task, in which participants were instructed to track a white line as accurately as possible. A secondary peripheral response task was introduced, in which participants were instructed to respond as quickly as possible to the peripheral stimuli, by pressing one of two clickers located on the steering wheel. The peripheral stimuli were located at 20º, 30º and 40º visual angle. Psychophysiological, performance and subjective measures were obtained before, during and after the main task. The pre- and post-tests included core body temperature, critical flicker fusion frequency threshold, a digit span memory test, Wits Sleepiness Scale and a NASA-TLX questionnaire. The psychophysiological and performance measures of heart rate, heart rate variability, blink frequency, blink duration, lane deviation, number of saccades towards peripheral stimuli, response time to peripheral stimuli and the percentage of missed peripheral responses were all recorded throughout the 90 minute main dual task. The results revealed significant differences (p<0.05) for heart rate variability, number of saccades towards peripheral stimuli and the Wits Sleepiness Scale, with regard to time of day. For time on task, significant effects were established for lane deviation, response time to peripheral stimuli, percentage of missed peripheral responses, heart rate, heart rate variability, blink frequency, blink duration, critical flicker fusion frequency threshold, core body temperature and the Wits Sleepiness Scale. Eccentricity was analysed and found to be significant for response time to peripheral stimuli, as well as for the percentage of missed peripheral responses; there was a significant increase in both measures with an increase in the stimuli eccentricity. No significances were established for time of day or between the pre- and post-tests conducted for the digit span memory performance; however, a significant interactional effect between the two was established. When assessing the percentage rate of decrement of driving performance compared to the percentage rate in the decrement of the missed peripheral responses, it was found that the percentage rate of decrement was equal for both measures. Thus from this research it can be seen that, concurrent with a decrement in driving performance, there are adverse effects on an individuals' peripheral vision, which have great implications for the safety of workers in industry and transport, as well as motorists. It was also established that time on task is possibly a more appropriate variable to consider than time of day, when implementing work schedules and rest breaks in industry, transport and fields alike, as more significant findings were seen for time on task compared to time of day. / Adobe Acrobat 9.53 Paper Capture Plug-in

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Driving simulation is widely accepted as a safe, effective, and economical alternative for investigating driver behavior in a variety of contexts. However, in order to apply simulator-based research results to real-world settings, the performance measures acquired through simulated driving experiments must first be validated. This research was aimed at validating the Oregon State University Driving Simulator based on speed, acceleration, and deceleration data. The validation effort consisted of a road test and a simulator test. The road test was completed on a five-lane urban principal arterial in Corvallis, Oregon, and the simulated environment matched the field conditions as closely as possible. Ten subjects participated in both tests. Minimum speed, maximum speed, average speed, 85th-percentile speed, maximum acceleration and maximum deceleration data variables were analyzed using graphical comparisons as well as two-sample paired t-tests. With the exception of minimum speed, all data variables showed statistically significant differences on at least one of the three test sections. However, the researchers considered the magnitude of these differences to be insignificant in a practical setting (on average, 3.5 mph for speed variables and 0.80 ft/s�� for acceleration and deceleration variables). Thus, the results of this research confirm the validity of the OSU driving simulator with regards to speed and acceleration. / Graduation date: 2013

Thesis (Ph. D.)--University of Washington, 2000. / Includes bibliographical references (leaves 44-52).

The purpose of the study was to examine the efficacy of virtual reality exposure therapy (VRET) to treat driving phobia using a multiple baseline across-subjects design. The sequence of events included a pre-treatment assessment, a baseline phase, 8 weekly VRET sessions using a standardized treatment protocol, a post-treatment assessment, and 1- and 3-month follow-up assessments. A sample of seven treatment seeking adults with a primary diagnosis of specific phobia (driving) was recruited. Five completed the treatment and follow-up phases. One individual withdrew after the pre-treatment assessment, and the other, after the first treatment session. It was hypothesized that VRET would reduce driving anxiety and avoidance symptoms between pre- and post-treatment assessments using several outcome measures. Visual and statistical analysis methods were used to assess treatment outcome. Three participants showed clear improvement in driving anxiety and avoidance symptoms between pre- and post-treatment assessments. There was a marginal improvement in these symptoms for one participant. The remaining participant showed very little improvement, and some outcome measures revealed slight deterioration in some of her symptoms. There was negligible change in actual driving frequency in any participant. Some gains were lost at the 1- and 3-month follow-up assessments, but symptoms remained far below pre-treatment results. Possibilities for future research and practice implications are discussed.

Thesis (M.Soc.Sc.)--University of Waikato, 2007. / Title from PDF cover (viewed February 29, 2008) Includes bibliographical references (p. 150-156)