729 research outputs found
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Effect of Feedback on Performance in the Lane-Change Test
No full textThe Lane-Change Test (LCT) is an easy-to-use methodological tool that has proven useful for researching dual-task driving situations. This paper examines the effect of feedback on LCT performance. Feedback is important for maintaining the focus of attention on the primary (driving) task and providing motivation for learning. An experiment was conducted in which two driver groups performed the LCT with or without end-of-block summary feedback. Results showed that the presence of feedback significantly improved performance, as revealed by lower overall means and lower standard deviations (with practice) of lateral deviation values. We conclude that feedback can have a positive effect on performance in the LCT and, therefore, it may be critical to include such feedback when using this, as well as similar tasks, to investigate dual-task driving situations
How Do Task Structure and Uncertainty Influence Task-Interleaving Strategies During Distracted Driving?
No full textDuring distracted driving, people commonly alternate or interleaveattention between driving and another task. One factor that influences taskinterleaving is task structure. Specifically, people tend to switch between tasks atsub-tasks boundaries. Uncertainty about the roadway environment during glancesaway from the road, however, may play a larger role in shaping task interleavingstrategies during distracted driving. The purpose of this study was to examine taskinterleaving strategies when drivers completed a distracting task of various subtasksizes. Participants entered phone numbers, modified zip codes, or digitstrings while performing a lane-keeping task. In general, the time between buttonpresses in the secondary task was significantly greater between sub-tasks thanwithin sub-tasks. However, as sub-tasks became larger drivers switched morefrequently within sub-tasks than between sub-tasks. Additionally, participants’ didnot change their visual sampling strategies as the size of sub-tasks increased.Thus, uncertainty influenced decisions to switch between two interleaved tasks inthe driving environment more than sub-task boundaries
Longitudinal Two-Year Follow-Up of Updating and Flexibility Functions in Drivers with Parkinson’s Disease: Preliminary Results
No full textThis paper outlines the preliminary results of a longitudinal follow up at two years interval (t0 versus t2) in 10 drivers with mild to moderate Parkinson’s disease (PD) and 10 matched controls. Changes of (1) driving habits assessed by a questionnaire, (2) neuropsychological performances measured by a set of cognitive tests and (3) cognitive abilities while driving using a simulator, were analyzed. Two types of changes were observed: the decline over time in PD group at two years interval and the appearance of some deficits in PD patients (compared to controls) at the second assessment (t2). These deficits were not observed at the first one (t0). The results showed that PD patients had changed their driving habits over time (reduction of mileage, more avoidance, underestimation of their own driving competency). The cognitive status of PD patients remained relatively stable over time, except for the Trail Making Test performances (part A and part B) which declined. A deficit for the TMT-part A in PD patients, compared to controls, appeared at t2. The data from driving simulator showed no significant decline in PD patients for both updating and flexibility performances. However, a deficit in flexibility appeared at t2 in PD patients, as demonstrated by their poorer performances on the flexibility cost. Our data suggest that flexibility may be significantly affected in PD patients with more advanced disease. The small size on our sample does not allow us any conclusion on updating function in both PD patients and controls
Cognitive and Psychomotor Correlates of Hazard Perception Ability and Risky Driving
No full textDeficits in specific cognitive and psychomotor capacities, such as attention, reaction time, memory, and hand-eye coordination ability are associated with increased crash risk, especially among older drivers (e.g., Anstey et al., 2005). Higher-order cognitive processes are also closely linked with hazard perception skills (e.g., Groeger, 2000). Employing a large professional driver sample, this study examines cognitive and psychomotor correlates of driver hazard perception detection accuracy (HPDA) and risky driving. Professional drivers (N = 2541) who applied to psycho-technical driver assessment centers were administered a number of computer-based measures of hazard perception, monotonous and selective attention, reasoning, visual pursuit, visual perception, hand-eye coordination, and reaction time. They also completed a self-reported measure of aberrant driver behaviors and reported the accidents involved and violation tickets taken in last three years. Results showed that attention capacity and psychomotor abilities were consistently associated with HPDA. Regression analyses revealed that selective attention, reasoning ability, and visual pursuit were moderately strong predictors of HPDA. These variables, however, weakly but significantly predicted the indicators of risky driving including aberrant driving behaviors, road traffic accidents, and violation tickets. These results suggest that hazard perception skills mediate the link between specific cognitive/perceptual skills and risky driving. The findings underscore the role of higher-order perceptual and cognitive processes, especially selective attention and reasoning, underlying hazard perception ability and have implications for driver assessment, training, and cognitive demands for driving
Fully-Automated Driving: The Road to Future Vehicles
No full textThe study investigated the impact of fully-automated vehicle control on driver behaviour, physiology and the uptake of secondary tasks in varying traffic conditions. Previous studies have indicated the potential ironies of such automation on fatigue, stress and situational awareness, but have also suggested potential benefits through enhanced safety, more efficient traffic flows and reduced driver workload. The research was undertaken in a high-fidelity driving simulator that allowed drivers to see, feel and hear the impact of the automated control. Independent factors of Drive Type (manual control, fully-automated) and Traffic Density (light, heavy) were manipulated in a repeated-measures experimental design. 49 drivers participated. Drivers experiencing full vehicle automation tended to refrain from behaviours, such as overtaking, that required them to temporarily retake manual control, accepting the resulting increase in journey time. Automation improved safety margins in car following, but this benefit was restricted only to conditions of light surrounding traffic. Automation also reduced heart rate and increased driver fatigue, the latter being mitigated somewhat by high traffic density. Furthermore, drivers became more heavily involved with in-vehicle entertainment than they were in manual driving, affording less visual attention to the road ahead. Drivers do appear happy to forgo their supervisory responsibilities in preference of a more entertaining automated drive. However, these responsibilities are taken more seriously as supervisory demand increases
A Comparison of Heart Rate and Heart Rate Variability Indices in Distinguishing Single-Task Driving and Driving Under Secondary Cognitive Workload
No full textHeart rate and heart rate variability (HRV) measures collected under actual highway driving from 25 young adults were compared to assess the relative sensitivity of each for distinguishing between a period of single task driving and periods of low and high additional cognitive workload. Basic heart rate, skin conductance and most, but not all, of the HRV indices were significantly different between single task driving and the high secondary demand period. Heart rate and skin conductance were also robust at distinguishing between single task driving and the low added demand period; however, several HRV measures did not show statistically significant differences between these two periods and the remaining HRV measures that did were less robust than basic heart rate as assessed by effect size and observed power. Rather than attempting to argue for the inherent superiority of any one physiological measure, these findings are presented with the intent of encouraging a broader discussion around the conditions under which particular physiological measures may be most useful and/or complementary for detecting different aspects of workload and operator state
Effects of Familiarity and Age on Driver Safety Errors During Wayfinding
No full textWayfinding is a critical skill that enables drivers to navigate from one location to another. Wayfinding abilities decline as individuals age, which may increase older driver reliance on directional cues (e.g. signs) and divert cognitive resources at the expense of vehicle control and safety. Familiarity with an environment can facilitate wayfinding due to previous knowledge of the route. This study examines the role of familiarity in driving safety errors committed during a wayfinding task. Results suggest that age-related driving difficulties can be lessened by familiarity with the environment. The results underscore the need to consider geographical license restrictions in administrative policies aimed at improving older driver safety
The Accuracy of Drivers’ Judgments of the Effects of Headlight Glare: Are We Really Blinded by the Light?
No full textHeadlights must balance two conflicting goals: maximizing visibility for the driver and minimizing glare to other drivers. Yet consumer complaints about headlights tend to focus on glare and not on poor visibility – a known casual factor of nighttime roadway crashes. These reactions may help to explain why drivers tend to underuse high beam headlights. This study explored the relationships among objective (impaired visual performance) and subjective (reports of discomfort and participants’ judgments of glare-induced visual impairments) consequences of headlight glare. Sixteen participants sat in a vehicle that moved slowly on a closed road and estimated the distance at which they could determine the orientation of a retroreflective Landolt C. Actual recognition distances and reports of glare-induced discomfort were also assessed. Observers’ overestimated the extent to which glare degraded their ability to see the target. Participants’ estimates of their own acuity decreased significantly when the opposing vehicle used high beams despite the fact that their actual acuity was unaffected. Overall, estimates of the disabling effects of glare were more tightly correlated with subjective reports of glare-induced discomfort than with actual visual performance. These results, which are consistent with psychophysical data obtained in a laboratory setting, may help explain drivers’ reluctance to use their high beams. The results also underscore the need to collect data on disability glare, not only discomfort glare, when evaluating new lighting technologies
Driver Rehabilitation in Parkinson’s Disease Using a Driving Simulator: A Pilot Study
No full textParkinson’s disease (PD) impairs driving performance. In this pilot study, four drivers with PD (selected based on poor road driving performance in the past) participated in a rehabilitation program using a driving simulator. Two different training drives (#1- multiple intersections of varying visibility and traffic load, where an incurring vehicle posed a crash risk, #2- various scenarios on decision making, hazard perception and response) were administered in each session (total 3 sessions once every 1-2 weeks) with immediate feedback after the drives. We observed reduction in crashes in drive #1 and improved scores on drive #2 in the simulator. In addition, 3 subjects showed marked improvements in their total error counts on a standard road test between baseline and post-training sessions, one subject stayed stable. These findings suggest that our simulator training program is feasible and potentially useful in impaired drivers with PD
Driving Consistency Errors Overestimate Crash Risk from Cellular Conversation in Two Case-Crossover Studies
No full textThe goal of this study is to help resolve the discrepancy in relative risk estimates between recent and early epidemiological studies of call-crash association. Recent epidemiological studies estimate a crash risk for cellular conversation near that of baseline driving – a relative risk of about one. In contrast, two early case-crossover studies estimated a relative crash risk of about four for cellular conversation while driving. One hypothesis to explain this fourfold discrepancy is that the early studies had less driving time in the control window on a day before the crash, than in the crash window just before the crash. This bias in driving exposure translated into relatively lower exposure to cellular conversation during control windows than during crash windows, thereby introducing an overestimate of the relative risk for cellular conversation while driving. To test this hypothesis, the present study developed a new driving consistency index (DCI), which measures the percentage overlap in driving times from one day to the next. The mean DCI for 240 vehicles in a Chicago GPS study with known driving times for two successive days was a surprisingly low 14.8%, substantially below the driving consistency estimates in the early case-crossover studies. After adjustment by the mean DCI, the relative risk estimates for cellular conversation while driving in the early case-crossover studies are about one, resolving the discrepancy with the more recent epidemiological studies