729 research outputs found
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Driver Control Actions in High-Speed Circular Driving
No full textIn this pilot study we investigate driver control actions during high speed cornering with a rear wheel drive vehicle. Six drivers were instructed to perform the fastest maneuvers possible around a marked circle, while trying to retain control of the vehicle and constant turning radius. The data reveal that stabilization of the vehicle is achieved with a combination of steering and throttle regulation. The results show that the drivers used steering control to compensate for disturbances in yaw rate and sideslip angle. Vehicle accustomed drivers had the most consistent performance resulting in reduced variance of task metrics and control inputs
Age-Related Limits of 3D Spatial Attention in Dual-Task Driving
No full textA previous experiment by Andersen, Ni, Bian and Kang (2010) examined the limits of 3D spatial attention in younger drivers. In the current experiment, we examined age-related differences in the extent of 3D spatial attention by assessing participants' ability to detect a light-change target in an array of lights over a simulated roadway while performing a car following task. We found that reaction time to light-change targets presented during a car following task varied as a function of distance and horizontal position in younger adults, but only a function of distance in older adults. That is, the breadth of spatial attention for older drivers is constant across various depths. However, the depth of spatial attention may be somewhat less for older drivers as they respond to targets far away at approximately the same speed as younger drivers do for the lights at the same distance in the most extreme horizontal position. The results of the present study suggest that tests to assess crash risk, such as the UFOV, are limited in scope because such tests fail to consider the variation in attention as a function of distance
Using In-Vehicle Devices to Examine Exposure and Patterns in Drivers with Parkinson’s Disease Compared to an Age-Matched Control Group
No full textSymptoms associated with Parkinson’s disease (PD), as well as medications, can influence safe driving. Some studies have shown that drivers with PD make more errors and may have more crashes. Although a few studies have suggested drivers with PD may self-regulate by reducing amount of driving and avoiding challenging situations, findings are based on self-report data. The purpose of this study was to objectively examine naturalistic driving exposure and patterns in drivers with PD compared to an age-matched group of healthy drivers using electronic, in-vehicle devices over a two week monitoring period. Compared to the controls, the PD group drove significantly less overall (number of trips, kilometres, duration), on weekends and at night. When adjusted for number of days of driving, the PD group still made fewer trips and drove proportionately less at night. This was the first study to examine the actual driving practices of a PD population using objective measures
Allocating Visual Attention: How Relevance to Driving Impacts Attention when Drivers are Distracted
No full textUse of cell phones while driving, and safety implications thereof, has captured public and scientific interest. Previous research has shown that driver reactions and visual attention are impacted by cell phone use, even when a handsfree device is used. In addition to these effects, Strayer and colleagues also found lower recognition for items present in the driving environment when drivers were using a cellular phone than when not using the phone. Strayer and colleagues used recognition as their primary measure of attention. Relevance to driving may have an impact on how attention is allocated to the environment via eye movements, separate from the impact on recognition memory. The current project used a medium-fidelity driving simulator to extend previous research by investigating how attention is allocated across driving-relevant and -irrelevant objects in the environment. Driving-relevant objects consisted of signs and potential hazards. Driving-irrelevant objects were billboards. Eye movement patterns (primarily measured by number of gazes) were impacted by distraction, and the pattern of gazes also differed across relevance levels, with hazards receiving the most gazes, and signs receiving the fewest. When only considering driving-relevant objects (i.e., signs vs. hazards), the eye movement measures showed an interaction between distraction and relevance. Signs received fewer gazes when drivers were distracted, whereas there was no comparable decrease in gazes to hazards
Dexamphetamine and Alcohol Effects in Simulated Driving and Cognitive Task Performance
No full textThis study assessed the effects of dexamphetamine with and without alcohol on simulated driving and cognitive tasks. 18 subjects participated in all 4 conditions: 10 mg dexamphetamine and 0.8g/kg alcohol, 10 mg dexamphetamine only, 0.8g/kg alcohol only, and a placebo control condition. A driving simulator was used to assess driving skills and risk taking on different road types. Cognitive performance was assessed using vigilance and divided attention tasks and subjects completed different rating scales. The main effects found were those of alcohol. This related to a larger standard deviation of lateral position, shorter accepted gap time and distance, higher average and maximum driving speeds and more violations of speed limits. A higher percentage of subjects in the dexamphetamine + alcohol condition did not stop for the red traffic lights, or collided with a vehicle. Performance of vigilance and divided attention tasks was impaired in the alcohol condition and impaired to a lesser degree in the dexamphetamine + alcohol condition. The conclusions of this study are that the main effect of impaired driving was found in the effect of 0.8 g/kg alcohol dose at the control level and the maneuvering level. The amphetamine dose did not potentiate risk taking behaviour, but also did not overcome the negative effects of alcohol. The findings of the present study justify the conclusion that drivers using 0.8 g/kg alcohol, or the combination of dexamphetamine with alcohol, pose a considerable traffic safety risk
The Effect of Visual Clutter on Driver Eye Glance Behavior
No full textDrivers’ eye glance behavior was examined as they drove on a variety of roadways that varied in visual clutter and the presence or absence of advertising billboards. Eye glance behavior appeared to be more heavily influenced by the nature of the driving task than by the stimulus attributes along the roadside. The mean proportion of glances to the road ahead ranged between 0.80 and 0.87 across conditions. The lowest mean proportion of glances to the road ahead was seen in conditions of high visual clutter, which contained off-premise billboards. Under high levels of clutter, drivers directed more glances to the left and right side of the road than under conditions of low clutter. The longest mean glance durations away from the forward roadway were to the right side of the road (0.105 s) and not to billboards. Mean glances to billboards were 0.078 s and 0.087 s under low and high clutter environments, respectively. The results showed that level of visual clutter present in the highway environment affects how drivers glance at scenes. However, this did not appear to be at the expense of focusing on the forward roadway
Traumatic Brain Injury and Driver Safety: A Systematic Review
No full textTraumatic brain injuries (TBI) can lead to impairments in cognitive, physical, and psychosocial functions, which may ultimately affect an individual’s ability to drive. A systematic review was conducted to: 1) assess the impact of TBI on crash risk/driving performance; 2) determine what factors associated with TBI are predictive of increased crash risk/poor driving performance; and 3) determine if there is a likelihood of future seizure among individuals with a TBI who did not experience a seizure at the time of the injury. Results indicated that: 1) The available evidence is insufficient to determine whether crash risk is elevated for drivers with TBI compared to uninjured controls (Summary RR=1.32; 95% CI=0.77-2.25). However, driving performance was significantly impaired among individuals with TBI compared to uninjured controls (Strength of Evidence: Moderate); 2) Cognitive function measured by certain neuropsychological tests may predict the outcome of driving performance measured by a road test for patients with TBI. (Strength of Evidence: Moderate); and 3) Individuals with TBI who have not experienced a seizure within the first week post-injury still have a significant likelihood of experiencing late seizure(s). Frequencies of late seizures ranged from 1% to 25% during follow-up periods ranging from 1 to 11 years (Strength of Evidence: Moderate). The highest rate of late seizures (25%) was associated primarily with penetrating missile TBIs (Strength of Evidence: Minimally Acceptable [32% vs. 5%]). These findings have potential implications for regulatory agencies with responsibility for road safety
Asymmetric Properties of Heart Rate Variability to Assess Operator Fatigue
No full textThe aim of this study is to evaluate the suitability of heart rate recordings for establishing a reliable connection to well-defined fatigue and performance measures in order to estimate fatigue in industrial and transportation applications. An overnight driving simulation scenario with partial sleep deprivation was utilized to induce strong fatigue. An experiment trial was divided into repeated sessions, each of which consisted of a driving performance and two vigilance tasks. Heart rate (HR) was recorded over the entire experiment; HRmeasures were derived and correlated against measures that were established from driving and vigilance task performance and that represent various aspects of operator fatigue. In a previous report (Hefner et al. 2009) we presented on the basis of the data of one volunteer that multiple fatigue measures correlate well with different expressions of heart rate variability (HRV), especially with longterm HRV derived from Poincaré plots. In this work, we intensify the Poincaré analysis by dividing the distribution of HR data in different accelerating and decelerating segments and by establishing properties of asymmetry between these segments. We also show that most of the properties of long-term HRV correlate well with specific fatigue measures for a group of 5 volunteers despite their large inter-individual differences in HR-to-fatigue correlations
Developing Driving Task Scenarios for Developmentally Tailored Driving Assessments: Using an Evidence-Centered Design Model
No full textA systematic procedure was described by which task scenarios can be derived as a basis for educationally informative and developmentally tailored driving assessments. To this end, Mislevy´s evidence centered design model for assessment was applied to the driving context. Borrowing from recent theories on driving and driving errors, task environment attributes were derived which may complicate the sub processes of driving and thus may result in varying task difficulty. A universe of assessment tasks was defined by combining basic driving tasks and critical task environment attributes. A collection of 55 critical driving task scenarios was selected from 39 video recorded driving lessons, throughout different stages of driving education. Results of a difficulty rating study pertaining to these scenarios including experienced driving instructors show that the scenarios discriminate well between beginning and advanced learner drivers. Successful scenario solution can be predicted by using an IRT function, where solution probability is a function of driver ability and task difficulty. Implications for assessment design activities are discussed
Dynamic Attention as a Predictor of Driving Performance in Clinical Populations: Preliminary Results
No full textExisting tests (e.g., useful field of view; UFOV) that are commonly used to evaluate visual attention when predicting at-risk drivers do not have a dynamic component. In this project, we developed a brief computerized test of dynamic visual attention (multiple object tracking; MOT). Estimates of threshold tracking speed from the brief MOT test showed good agreement with those determined by a full psychometric function (n = 41, r = 0.876, p < 0.001). The brief MOT test was then implemented in a clinical driving assessment program; participants with poorer MOT scores had higher error scores on the road test (n = 15, r = -0.670, p = 0.006)