| 1. |
- Barbieri, Dechristian Franca, et al.
(författare)
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Comparison of sedentary behaviors in office workers using sit-stand tables with and without semi-automated position changes
- 2017
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 59:5, s. 782-795
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study compared usage patterns of two different electronically controlled sit-stand tables during a 2-month intervention period among office workers.Background: Office workers spend most of their working time sitting, which is likely detrimental to health. Although the introduction of sit-stand tables has been suggested as an effective intervention to decrease sitting time, limited evidence is available on usage patterns of sit-stand tables, and whether patterns are influenced by table configuration.Methods: Twelve workers were provided with standard sit-stand tables (non-automated table group) and 12 with semi-automated sit-stand tables programmed to change table position according to a pre-set pattern, if the user agreed to the system-generated prompt (semi-automated table group). Table position was monitored continuously for two months after introducing the tables, as a proxy for sit-stand behavior.Results: On average, the table was in a “sit” position for 85% of the work-day in both groups; this did not change significantly during the 2-month period. Switches in table position from sit to stand were, however, more frequent in the semi-automated table group than in the non-automated table group (0.65 vs. 0.29 hr-1; p=0.001).Conclusion: Introducing a semi-automated sit-stand table appeared to be an attractive alternative to a standard sit-stand table, since it led to more posture variation.Application: A semi-automated sit-stand table may effectively contribute to making postures more variable among office workers, and thus aid in alleviating negative health effects of extensive sitting.
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| 2. |
- Bianchi Piccinini, Giulio, 1982, et al.
(författare)
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How Do Drivers Respond to Silent Automation Failures? Driving Simulator Study and Comparison of Computational Driver Braking Models
- 2020
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Ingår i: Human Factors. - Chalmers University of Technology, Gothenburg, Sweden.; Volvo Group Trucks Technology, Gothenburg, Sweden.; Virginia Tech Transportation Institute, Blacksburg, USA.; University of Leeds, UK.; VTI, Gothenburg, Sweden. : SAGE Publications. - 1547-8181 .- 0018-7208. ; 62:7, s. 1212-1229
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This paper aims to describe and test novel computational driver models, predicting drivers’ brake reaction times (BRTs) to different levels of lead vehicle braking, during driving with cruise control (CC) and during silent failures of adaptive cruise control (ACC). Background: Validated computational models predicting BRTs to silent failures of automation are lacking but are important for assessing the safety benefits of automated driving. Method: Two alternative models of driver response to silent ACC failures are proposed: a looming prediction model, assuming that drivers embody a generative model of ACC, and a lower gain model, assuming that drivers’ arousal decreases due to monitoring of the automated system. Predictions of BRTs issued by the models were tested using a driving simulator study. Results: The driving simulator study confirmed the predictions of the models: (a) BRTs were significantly shorter with an increase in kinematic criticality, both during driving with CC and during driving with ACC; (b) BRTs were significantly delayed when driving with ACC compared with driving with CC. However, the predicted BRTs were longer than the ones observed, entailing a fitting of the models to the data from the study. Conclusion: Both the looming prediction model and the lower gain model predict well the BRTs for the ACC driving condition. However, the looming prediction model has the advantage of being able to predict average BRTs using the exact same parameters as the model fitted to the CC driving data. Application: Knowledge resulting from this research can be helpful for assessing the safety benefits of automated driving.
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| 3. |
- Ciccarelli, Marina, et al.
(författare)
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Variation in Muscle Activity Among Office Workers When Using Different Information Technologies at Work and Away From Work
- 2013
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 55:5, s. 911-923
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To determine differences in muscle activity amplitudes and variation of amplitudes, when using different Information and Communication Technologies (ICT).Background: Office workers use different ICT to perform tasks. Upper body musculoskeletal complaints are frequently reported by this occupational group. Increased muscle activity and insufficient muscle activity variation are potential risk factors for musculoskeletal complaints.Method: Muscle activity of right and left upper trapezius and right wrist extensor muscle bundle (extensor carpi radialis longus and brevis) of 24 office workers (performing their usual tasks requiring different ICT at work and away-from-work) were measured continuously over 10-12 hours. Muscle activity variation was quantified using two indices, APDF(90-10) and EVAsd.Results: There was a trend for electronics-based New ICT tasks to involve less electromyography (EMG) variation than paper-based Old ICT tasks. Performing Combined ICT tasks (i.e. using paper- and electronics-based ICT simultaneously) resulted in the highest muscle activity levels and least variation; however, these Combined ICT tasks were rarely performed. Tasks involving no ICT (Non-ICT) had the greatest muscle activity variation.Conclusion: Office workers in this study used various ICT during tasks at work and away-from-work. The high EMG amplitudes and low variation observed when using Combined ICT may present the greatest risk for musculoskeletal complaints, and use of Combined ICT by workers should be kept low in office work. Breaking up Combined, New and Old ICT tasks; for example, by interspersing highly variable Non-ICT tasks into office workers’ daily tasks, could increase overall muscle activity variation and reduce risk for musculoskeletal complaints.
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| 4. |
- Dahlman, Joakim, 1974-, et al.
(författare)
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Performance and Autonomic Responses during Motion Sickness
- 2009
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 51:1, s. 56-66
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of the study was to investigate how motion sickness, triggered by an optokinetic drum, affects short term memory performance and to explore autonomic responses to perceived motion sickness. Background: Previous research has found motion sickness to decrease performance, but it is not known how short term memory in particular is affected. Method: Thirty-eight healthy participants performed a listening span test while seated in a rotating optokinetic drum. Measurements of motion sickness, performance, heart rate, skin conductance, blood volume pulse, and pupil size were performed simultaneously throughout the experiment. Results: A total of 16 participants terminated the trial due to severe nausea, while the other 22 endured the full 25 minutes. Perceived motion sickness increased over time in both groups, but less among those who endured the trial. Short term memory performance decreased towards the end for those who terminated, while it increased for the other group. Results from the measured autonomic responses were ambiguous. Conclusion: The present study concludes that performance, measured as short term memory, declines as perceived motion sickness progresses. Application: This research has potential implications for command and control personnel in risk of developing motion sickness.
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| 5. |
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| 6. |
- Duncan, Carolyn A., et al.
(författare)
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The Effect of Wave Motion Intensities on Performance in a Simulated Search and Rescue Task and the Concurrent Demands of Maintaining Balance
- 2022
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 64:3, s. 579-588
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Tidskriftsartikel (refereegranskat)abstract
- Objective The purpose of this study was to examine how intensity of wave motions affects the performance of a simulated maritime search and rescue (SAR) task. Background Maritime SAR is a critical maritime occupation; however, the effect of wave motion intensity on worker performance is unknown. Methods Twenty-four participants (12 male, 12 female) performed a simulated search and rescue task on a six-degree-of-freedom motion platform in two conditions that differed in motion intensity (low and high). Task performance, electromyography (EMG), and number of compensatory steps taken by the individual were examined. Results As magnitude of simulated motion increased, performance in the SAR task decreased, and was accompanied by increases in lower limb muscle activation and number of steps taken. Conclusions Performance of an SAR task and balance control may be impeded by high-magnitude vessel motions. Application This research has the potential to be used by maritime engineers, occupational health and safety professionals, and ergonomists to improve worker safety and performance for SAR operators.
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| 7. |
- Engström, Johan A Skifs, 1973, et al.
(författare)
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Effects of working memory load and repeated scenario exposure on emergency braking performance
- 2010
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 52:5, s. 551-559
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of the present study was to examine the effect of working memory load on drivers' responses to a suddenly braking lead vehicle and whether this effect (if any) is moderated by repeated scenario exposure. Background: Several experimental studies have found delayed braking responses to lead vehicle braking events during concurrent performance of nonvisual, working memory-loading tasks, such as hands-free phone conversation. However, the common use of repeated, and hence somewhat expected, braking events may undermine the generalizability of these results to naturalistic, unexpected, emergency braking scenarios. Method: A critical lead vehicle braking scenario was implemented in a fixed-based simulator. The effects of working memory load and repeated scenario exposure on braking performance were examined. Results: Brake response time was decomposed into accelerator pedal release time and accelerator-to-brake pedal movement time. Accelerator pedal release times were strongly reduced with repeated scenario exposure and were delayed by working memory load with a small but significant amount (178 ms). The two factors did not interact. There were no effects on accelerator-to-brake pedal movement time. Conclusion:The results suggest that effects of working memory load on response performance obtained from repeated critical lead vehicle braking scenarios may be validly generalized to real world unexpected events. Application: The results have important implications for the interpretation of braking performance in experimental settings, in particular in the context of safety-related evaluation of in-vehicle information and communication technologies. © 2010, Human Factors and Ergonomics Society.
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| 8. |
- Eriksson, Lars, 1963-, et al.
(författare)
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Effects of visual flow display of flight maneuvers on perceived spatial orientation
- 2005
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Ingår i: Human Factors. - 0018-7208 .- 1547-8181. ; 47:2, s. 378-393
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Tidskriftsartikel (refereegranskat)abstract
- Postural responses were utilized as measures of the effectiveness of a wide-angle visual flow display in determining perceived spatial orientation (SO). The general experimental setup included a 150 degrees x 34 degrees wide-field display showing flight over computer-generated ground with horizon. Simulated roll maneuvers on this display induced postural sway in the observer that was registered by a head-tracker system. Two experiments with 16 participants in each investigated the effects of visual flow, display exclusions in the central visual field, and display extensions into the visual periphery. Clear vestibular and proprioceptive suppression effects were demonstrated on postural sway with the inclusion of visual flow of forward ego motion in roll maneuvers. Compared with the full view, up to 20 degrees x 20 degrees central field omission either did not reduce the effect or reduced the effect but, frequently, only moderately. Limiting the display area to 45 degrees in the horizontal dimension reduced display effectiveness significantly, whereas a 105 degrees area did not, compared with the full view. Utilizing postural responses as indications of visual display resonance with our SO mechanism, actual or potential applications of this research include the design of an interface integrating flight-adapted visual flow to counteract or reduce pilot spatial disorientation.
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| 9. |
- Friberg, Marc, et al.
(författare)
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The Effects of Stress on Tourniquet Application and CPR Performance in Layperson and Professional Civilian Populations
- 2023
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Ingår i: Human Factors. - : SAGE PUBLICATIONS INC. - 0018-7208 .- 1547-8181. ; 65:3, s. 496-507
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Tidskriftsartikel (refereegranskat)abstract
- Objective The purpose of this study was to compare laypeoples and professional first responders ability to perform tourniquet application and cardiopulmonary resuscitation (CPR) during calm and stressful circumstances. Background Life-threatening bleeding is a major cause of death that could be prevented by fast and appropriate first aid interventions. Therefore, laypeople are now being trained in bleeding control skills, transforming them from bystanders to immediate responders. However, critics have questioned whether laypeople are able to perform during more stressful conditions. Method Twenty-four laypersons and 31 professional first responders were tested in two conditions: a calm classroom scenario and a stressful scenario consisting of paintball fire and physical exertion. Stress and workload were assessed along with task performance. Results The experimental manipulation was successful in terms of eliciting stress reactions. Tourniquet application performance did not decline in the stressful condition, but some aspects of CPR performance did for both groups. First responders experienced higher task engagement and lower distress, worry and workload than the laypeople in both the calm and stressful conditions. Conclusion Stress did not affect first responders and laypeople differently in terms of performance effects. Stress should therefore not be considered a major obstacle for teaching bleeding control skills to laypeople. Application Tourniquet application can be taught to laypeople in a short amount of time, and they can perform this skill during stress in controlled settings. Concerns about laypeoples ability to perform under stress should not exclude bleeding control skills from first aid courses for civilian laypeople.
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| 10. |
- Gillespie, B. M., et al.
(författare)
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The Impact of Robotic-Assisted Surgery on Team Performance: A Systematic Mixed Studies Review
- 2021
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208. ; 63:8, s. 1352-1379
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Tidskriftsartikel (refereegranskat)abstract
- Objective The aim of this study is to describe the impact of robotic-assisted surgery on team performance in the operating room. Background The introduction of surgical robots has improved the technical performance of surgical procedures but has also contributed to unexpected interactions in surgical teams, leading to new types of errors. Method A systematic literature search of Cumulative Index to Nursing and Allied Health Literature, PubMed, ProQuest, Cochrane, Web of Science, PsycINFO, and Scopus databases using key words and MeSH terms was conducted. Screening identified studies employing qualitative and quantitative methods published between January 2000 and September 2019. Two reviewers independently appraised the methodological quality of the articles using theMixed Methods Appraisal Tool(2018). Discussions were held among authors to examine quality scores of the studies and emergent themes, and agreement was reached through consensus. Themes were derived using inductive content analysis. Results Combined searches identified 1,065 citations. Of these, 19 articles, 16 quantitative and 3 qualitative, were included. Robotic-assisted surgeries included urology, gynecology, cardiac, and general procedures involving surgeons, anesthetists, nurses, and technicians. Three themes emerged: Negotiating the altered physical environs and adapting team communications to manage task and technology; managing the robotic system to optimize workflow efficiency; andtechnical proficiency depends on experience, team familiarity, and case complexity. Conclusion Inclusion of a robot as a team member adds further complexity to the work of surgery. Application These review findings will inform training programs specifically designed to optimize teamwork, workflow efficiency, and learning needs.
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| 11. |
- Gold, Judith, et al.
(författare)
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Serum and MRI biomarkers in mobile device texting : a pilot study
- 2014
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 56:5, s. 864-872
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We aimed to determine if serum biochemical and MRI biomarkers differed between high volume (≥ 230 texts sent/day; n = 5) and low volume (≤ 25 texts sent/day; n = 5) texters. A secondary aim was to ascertain what correlations between the biochemical and imaging biomarkers could tell us about the pathophysiology of early onset tendinopathies.Background: Text messaging has become widespread, particularly among college-aged young adults. There is concern that high rates of texting may result in musculoskeletal disorders, including tendinopathies. Pathophysiology of tendinopathies is largely unknown.Method: Ten females with a mean age of 20 were recruited. We examined serum for 20 biomarkers of inflammation, tissue degeneration and repair. We used conventional MRI and MRI mean intratendinous signal intensity (MISI) to assess thumb tendons. Correlations between MISI and serum biomarkers were also examined.Results: Three high volume texters had MRI tendinopathy findings as did one low volume texter. Increased serum TNF-R1 was found in high volume texters compared to low volume texters, as were non-significant increases in MISI in two thumb tendons. Serum TNF-R1 and TNF-α correlated with MISI in these tendons, as did IL1-R1. Conclusion: These results suggest that early onset tendinopathy with concurrent inflammation may be occurring in prolific texters. Further studies with larger sample sizes are needed for confirmation.
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| 12. |
- Helander, Martin
(författare)
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Drivers' Steering Behavior during Traffic Events: A Case of Perceptual Tropism?
- 1978
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 20:6, s. 681-690
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Tidskriftsartikel (refereegranskat)abstract
- Seventy-five drivers participated in test runs, driving a total of 1500 km. Mean value and 1 standard deviation of steering wheel angle were plotted for several traffic events from 10 s before the event until 10 s after. Two seconds before meeting an oncoming car, there was a 1° shift in steering wheel angle to the left, thereby moving toward the oncoming car. The peak value was obtained at the instant when the oncoming car passed. The original steering wheel position was regained 2 s after the meeting. The behavior was more pronounced on narrow roads than on wide roads, and it was unaffected by driving experience. The behavior is explained by the perceptual significance of the oncoming car and, in analogy with tropistic behavior noted in lower organisms, the phenomenon is called perceptual tropism. The findings introduce a new dimension to analyses of steering behavior. More important, the obtained results suggest that there are interactions between visual and motor behavior.
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| 13. |
- Jackson, Jennie, et al.
(författare)
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Should We Be More on the Ball? : The Efficacy of Accommodation Training on Lumbar Spine Posture, Muscle Activity, and Perceived Discomfort During Stability Ball Sitting
- 2013
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 55:6, s. 1064-1076
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to evaluate the efficacy of a 9-day accommodation protocol on reducing perceived discomfort while sitting on a stability ball (SB); trunk muscle activity levels and lumbar spinal postures were also considered. Background: Previous studies have compared SB sitting with office chair sitting with few observed differences in muscle activity or posture; however, greater discomfort during SB sitting has been reported. These findings may indicate an accommodation period is necessary to acclimate to SB sitting. Method: For this study, 6 males and 6 females completed two separate, 2-hr sitting sessions on an SB. Half the participants completed a 9-day accommodation period between the visits, whereas the other half did not use an SB during the time. On both occasions, self-reported perceived discomfort ratings were collected along with erector spinae and abdominal muscle activity and lumbar spinal postures. Results: Discomfort ratings were reduced in female participants following the accommodation; no effects on muscle activation or lumbar spine postures were observed. Conclusion: Accommodation training may reduce perceived low-back discomfort in females. Trunk muscle activity and lumbar spine postures during seated office work on an SB did not differ between groups; however, greater sample power was required to conclusively address these variables. Application: Regarding whether to use an SB in place of a standard office chair, this study indicates that females electing to use an SB can decrease discomfort by following an accommodation protocol; no evidence was found to indicate that SB chair use will improve trunk strength or posture, even following an accommodation period.
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| 14. |
- Kircher, Katja, 1973-, et al.
(författare)
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Minimum Required Attention : A Human-Centered Approach to Driver Inattention
- 2017
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Ingår i: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 59:3, s. 471-484
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To propose a driver attention theory based on the notion of driving as a satisficing and partially self-paced task and, within this framework, present a definition for driver inattention.Background: Many definitions of driver inattention and distraction have been proposed, but they are difficult to operationalize, and they are either unreasonably strict and inflexible or suffer from hindsight bias.Method: Existing definitions of driver distraction are reviewed and their shortcomings identified. We then present the minimum required attention (MiRA) theory to overcome these shortcomings. Suggestions on how to operationalize MiRA are also presented.Results: MiRA describes which role the attention of the driver plays in the shared "situation awareness of the traffic system." A driver is considered attentive when sampling sufficient information to meet the demands of the system, namely, that he or she fulfills the preconditions to be able to form and maintain a good enough mental representation of the situation. A driver should only be considered inattentive when information sampling is not sufficient, regardless of whether the driver is concurrently executing an additional task or not.Conclusions: The MiRA theory builds on well-established driver attention theories. It goes beyond available driver distraction definitions by first defining what a driver needs to be attentive to, being free from hindsight bias, and allowing the driver to adapt to the current demands of the traffic situation through satisficing and self-pacing. MiRA has the potential to provide the stepping stone for unbiased and operationalizable inattention detection and classification.
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| 15. |
- Kircher, Katja, 1973-, et al.
(författare)
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On the Difference Between Necessary and Unnecessary Glances Away From the Forward Roadway : An Occlusion Study on the Motorway
- 2020
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Ingår i: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 62:7, s. 1117-1131
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The present study strove to distinguish traffic-related glances away from the forward roadway from non-traffic-related glances while assessing the minimum amount of visual information intake necessary for safe driving in particular scenarios.Background: Published gaze-based distraction detection algorithms and guidelines for distraction prevention essentially measure the time spent looking away from the forward roadway, without incorporating situation-based attentional requirements. Incorporating situation-based attentional requirements would entail an approach that not only considers the time spent looking elsewhere but also checks whether all necessary information has been sampled.Method: We assess the visual sampling requirements for the forward view based on 25 experienced drivers’ self-paced visual occlusion in real motorway traffic, dependent on a combination of situational factors, and compare these with their corresponding glance behavior in baseline driving.Results: Occlusion durations were on average 3 times longer than glances away from the forward roadway, and they varied substantially depending on particular maneuvers and on the proximity of other traffic, showing that interactions with nearby traffic increase perceived uncertainty. The frequency of glances away from the forward roadway was relatively stable across proximity levels and maneuvers, being very similar to what has been found in naturalistic driving.Conclusion: Glances away from the forward roadway proved qualitatively different from occlusions in both their duration and when they occur. Our findings indicate that glancing away from the forward roadway for driving purposes is not the same as glancing away for other purposes, and that neither is necessarily equivalent to distraction.
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| 16. |
- Kujala, Tuomo, et al.
(författare)
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A Review of Occlusion as a Tool to Assess Attentional Demand in Driving
- 2023
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Ingår i: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 65:5, s. 792-808
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this review is to identify how visual occlusion contributes to our understanding of attentional demand and spare visual capacity in driving and the strengths and limitations of the method.Background: The occlusion technique was developed by John W. Senders to evaluate the attentional demand of driving. Despite its utility, it has been used infrequently in driver attention/inattention research.Method: Visual occlusion studies in driving published between 1967 and 2020 were reviewed. The focus was on original studies in which the forward visual field was intermittently occluded while the participant was driving.Results: Occlusion studies have shown that attentional demand varies across situations and drivers and have indicated environmental, situational, and inter-individual factors behind the variability. The occlusion technique complements eye tracking in being able to indicate the temporal requirements for and redundancy in visual information sampling. The proper selection of occlusion settings depends on the target of the research.Conclusion: Although there are a number of occlusion studies looking at various aspects of attentional demand, we are still only beginning to understand how these demands vary, interact, and covary in naturalistic driving.Application: The findings of this review have methodological and theoretical implications for human factors research and for the development of distraction monitoring and in-vehicle system testing. Distraction detection algorithms and testing guidelines should consider the variability in drivers’ situational and individual spare visual capacity.
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| 17. |
- Kumar, Arun, 1991, et al.
(författare)
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Prediction of Drivers’ Subjective Evaluation of Vehicle Reaction Under Aerodynamic Excitations
- 2024
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 66:5, s. 1600-1615
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objectives are to determine which quantities are important to measure to determine how drivers perceive vehicle stability, and to develop a regression model to predict which induced external disturbances drivers are able to feel. Background: Driver experience of a vehicle’s dynamic performance is important to auto manufacturers. Test engineers and test drivers perform several on-road assessments to evaluate the vehicle’s dynamic performance before sign-off for production. The presence of external disturbances such as aerodynamic forces and moments play a significant role in the overall vehicle assessment. As a result, it is important to understand the relation between the subjective experience of the drivers and these external disturbances acting on the vehicle. Method: A sequence of external yaw and roll moment disturbances of varying amplitudes and frequencies is added to a straight-line high-speed stability simulation test in a driving simulator. The tests are performed with both common and professional test drivers, and their evaluations to these external disturbances are recorded. The sampled data from these tests are used to generate the needed regression model. Results: A model is derived for predicting which disturbances drivers can feel. It quantifies difference in sensitivity between driver types and between yaw and roll disturbances. Conclusion: The model shows a relationship between steering input and driver sensitivity to external disturbances in a straight-line drive. Drivers are more sensitive to yaw disturbance than roll disturbance and increased steering input lowers sensitivity. Application: Identify the threshold above which unexpected disturbances such as aerodynamic excitations can potentially create unstable vehicle behaviour.
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| 18. |
- Liu, Zhuofan, et al.
(författare)
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Attentional Demand as a Function of Contextual Factors in Different Traffic Scenarios
- 2019
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Ingår i: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 62:17, s. 1171-1189
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To assess the attentional demand of different contextual factors in driving.Background: The attentional demand on the driver varies with the situation. One approach for estimating the attentional demand, via spare capacity, is to use visual occlusion.Method: Using a 3 × 5 within-subjects design, 33 participants drove in a fixed-base simulator in three scenarios (i.e., urban, rural, and motorway), combined with five fixed occlusion durations (1.0, 1.4, 1.8, 2.2, and 2.6 s). By pressing a microswitch on a finger, the driver initiated each occlusion, which lasted for the same predetermined duration within each trial. Drivers were instructed to occlude their vision as often as possible while still driving safely.Results: Stepwise logistic regression per scenario indicated that the occlusion predictors varied with scenario. In the urban environment, infrastructure-related variables had the biggest influence, whereas the distance to oncoming traffic played a major role on the rural road. On the motorway, occlusion duration and time since the last occlusion were the main determinants.Conclusion: Spare capacity is dependent on the scenario, selected speed, and individual factors. This is important for developing workload managers, infrastructural design, and aspects related to transfer of control in automated driving.Application: Better knowledge of the determinants of spare capacity in the road environment can help improve workload managers, thereby contributing to more efficient and safer interaction with additional tasks.
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| 19. |
- Ljungberg, Jessica K., et al.
(författare)
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The Impact of Intonation and Valence on Objective and Subjective Attention Capture by Auditory Alarms
- 2012
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Ingår i: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 54:5, s. 826-837
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Tidskriftsartikel (refereegranskat)abstract
- Objective:The objective was to study the involuntary capture of attention by spoken words varying in intonation and valence.Background:In studies of verbal alarms, the propensity of alarms to capture attention has been primarily assessed with the use of subjective ratings of their perceived urgency. Past studies suggest that such ratings vary with the alarms’ spoken urgency and content.Method:We measured attention capture by spoken words varying in valence (negative vs. neutral) and intonation (urgently vs. nonurgently spoken) through subjective ratings and behavioral measures. The key behavioral measure was the response latency to visual stimuli in the presence of spoken words breaking away from the periodical repetition of a tone.Results:The results showed that all words captured attention relative to a baseline standard tone but that this effect was partly counteracted by a relative speeding of responses for urgently compared with nonurgently spoken words. Word valence did not affect behavioral performance. Rating data showed that both intonation and valence increased significantly perceived urgency and attention grabbing without any interaction.Conclusion:The data suggest a congruency between subjective ratings and behavioral performance with respect to spoken intonation but not valence.Application:This study demonstrates the usefulness and feasibility of objective measures of attention capture to help design efficient alarm systems.
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| 20. |
- Lo, Julia C., et al.
(författare)
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Individual Markers of Resilience in Train Traffic Control : The Role of Operators' Goals and Strategic Mental Models and Implications for Variation, Expertise, and Performance
- 2016
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 58:1, s. 80-91
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to examine individual markers of resilience and obtain quantitative insights into the understanding and the implications of variation and expertise levels in train traffic operators' goals and strategic mental models and their impact on performance. Background: The Dutch railways are one of the world's most heavy utilized railway networks and have been identified to be weak in system and organizational resilience. Method: Twenty-two train traffic controllers enacted two scenarios in a human-in-the-loop simulator. Their experience, goals, strategic mental models, and performance were assessed through questionnaires and simulator logs. Goals were operationalized through performance indicators and strategic mental models through train completion strategies. Results: A variation was found between operators for both self-reported primary performance indicators and completion strategies. Further, the primary goal of only 14% of the operators reflected the primary organizational goal (i.e., arrival punctuality). An incongruence was also found between train traffic controllers' self-reported performance indicators and objective performance in a more disrupted condition. The level of experience tends to affect performance differently. Conclusion: There is a gap between primary organizational goals and preferred individual goals. Further, the relative strong diversity in primary operator goals and strategic mental models indicates weak resilience at the individual level. Application: With recent and upcoming large-scale changes throughout the sociotechnical space of the railway infrastructure organization, the findings are useful to facilitate future railway traffic control and the development of a resilient system.
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| 21. |
- Markkula, Gustav M, 1978, et al.
(författare)
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A Review of Near-Collision Driver Behavior Models
- 2012
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 54:6, s. 1117-1143
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This article provides a review of recent models of driver behavior in on-road collision situations.Background: In efforts to improve traffic safety, computer simulation of accident situations holds promise as a valuable tool, for both academia and industry. However, to ensure the validity of simulations, models are needed that accurately capture near-crash driver behavior, as observed in real traffic or driving experiments.Method: Scientific articles were identified by a systematic approach, including extensive database searches. Criteria for inclusion were defined and applied, including the requirement that models should have been previously applied to simulate on-road collision avoidance behavior. Several selected models were implemented and tested in selected scenarios.Results: The reviewed articles were grouped according to a rough taxonomy based on main emphasis, namely avoidance by braking, avoidance by steering, avoidance by a combination of braking and steering, effects of driver states and characteristics on avoidance, and simulation platforms.Conclusion: A large number of near-collision driver behavior models have been proposed. Validation using human driving data has often been limited, but exceptions exist. The research field appears fragmented, but simulation-based comparison indicates that there may be more similarity between models than what is apparent from the model equations. Further comparison of models is recommended.Application: This review provides traffic safety researchers with an overview of the field of driver models for collision situations. Specifically, researchers aiming to develop simulations of on-road collision accident situations can use this review to find suitable starting points for their work.
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| 22. |
- Montgomery, Henry, et al.
(författare)
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Engaging in activities involving information technology : dimensions, modes, and flow
- 2004
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Ingår i: Human Factors. - Santa Monica : Human factors. - 0018-7208 .- 1547-8181. ; 46:2, s. 334-348
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Tidskriftsartikel (refereegranskat)abstract
- An engagement mode involves a subject (e.g., a user of information technology, or IT) who is engaged in an activity with an object in a certain manner (the mode). The purpose of this study is to develop a general model of engagement modes that may be used for understanding how IT-related activities are shaped by properties of the user and the IT object. A questionnaire involving items on IT engagement and the experience of flow was administered to 300 participants. The results supported an engagement mode (EM) model involving 5 different engagement modes (enjoying/acceptance, ambition/curiosity, avoidance/hesitation, frustration/anxiety, and efficiency/productivity) characterized on 3 dimensions (evaluation of object, locus of control between subject and object, and intrinsic or extrinsic focus of motivation). The flow experience follows from a balance between enjoying/acceptance and efficiency/productivity propelled by ambition/curiosity. The EM model could provide a platform for considering how IT users, IT applications, and IT environments should work together to yield both enjoyment and efficiency. Actual or potential applications of this research include designing IT training programs on different levels of specificity.
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| 23. |
- Nordqvist, Tommy, et al.
(författare)
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Fatigue and reading of text on videotex
- 1986
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 28:3, s. 353-363
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Tidskriftsartikel (refereegranskat)abstract
- Examined the effects of fatigue during the reading of texts presented by means of a videotex system or by means of print on paper in 3 experiments with 72 undergraduates. The 2-hr reading task was interrupted 6 times for tests of speed and accuracy in scanning a matrix of letters for given target letters, speed and accuracy in an auditory-motor reaction time (RT) task, and a free recall test of the information presented prior to each text session. The 3 experiments differed with respect to task demands. Exp I was less demanding than Exp II, which was less demanding than Exp III. It was predicted that Ss who read the texts presented on videotex would show more dramatic effects than Ss who read texts under more regular print-on-paper conditions. It was also predicted that these effects would be more pronounced for more demanding tasks. Results demonstrate only marginal effects of fatigue. It is suggested that some effects could be interpreted as more fatigue in the videotex group than in the print group. The increase in task demands resulted in longer scanning and RTs, but accuracy data were unaffected.
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| 24. |
- Oskarsson, Per-Anders, et al.
(författare)
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Enhanced perception and performance by multimodal threat cueing in simulated combat vehicle
- 2012
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 54:1, s. 121-136
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Tidskriftsartikel (refereegranskat)abstract
- Objective:In a simulated combat vehicle, uni-, bi-, and trimodal cueing of direction to threat were compared with the purpose to investigate whether multisensory redundant information may enhance dynamic perception and performance. Background: Previous research has shown that multimodal display presentation can enhance perception of information and task performance. Method: Two experiments in a simulated combat vehicle were performed under the instructions to turn the vehicle toward the threat as fast and accurately as possible after threat cue onset. In Experiment 1, direction to threat was presented by four display types: visual head-down display, tactile belt, 3-D audio, and trimodal with the three displays combined. In Experiment 2, direction to threat was presented by three display types: visual head-up display (HUD)–3-D audio, tactile belt–3-D audio, and trimodal with HUD, tactile belt, and 3-D audio combined. Results: In Experiment 1, the trimodal display provided overall best performance and perception of threat direction. In Experiment 2, both the trimodal and HUD–3-D audio displays led to overall best performance, and the trimodal display provided overall the best perception of threat direction. None of the trimodal displays induced higher mental workload or secondary task interference. Conclusion: The trimodal displays provided overall enhanced perception and performance in the dynamically framed threat scenario and did not entail higher mental workload or decreased spare capacity. Application: Trimodal displays with redundant information may contribute to safer and more reliable peak performance in time-critical dynamic tasks and especially in more extreme and stressful situations with high perceptual or mental workload.
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| 25. |
- Pipkorn, Linda, 1991, et al.
(författare)
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Driver Visual Attention Before and After Take-Over Requests During Automated Driving on Public Roads
- 2024
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 66:2, s. 336-347
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Tidskriftsartikel (refereegranskat)abstract
- Objective This study aims to understand drivers’ visual attention before and after take-over requests during automated driving (AD), when the vehicle is fully responsible for the driving task on public roads. Background Existing research on transitions of control from AD to manual driving has mainly focused on take-over times. Despite its relevance for vehicle safety, drivers’ visual attention has received little consideration. Method Thirty participants took part in a Wizard of Oz study on public roads. Drivers’ visual attention was analyzed before and after four take-over requests. Visual attention during manual driving was also recorded to serve as a baseline for comparison. Results During AD, the participants showed reduced visual attention to the forward road and increased duration of single off-road glances compared to manual driving. In response to take-over requests, the participants looked away from the forward road toward the instrument cluster. Levels of visual attention towards the forward road did not return to the levels observed during manual driving until after 15 s had passed. Conclusion During AD, drivers may look toward non-driving related task items (e.g., mobile phone) instead of forward. Further, when a transition of control is required, drivers may take over control before they are aware of the driving environment or potential threat(s). Thus, it cannot be assumed that drivers are ready to respond to events shortly after the take-over request. Application It is important to consider the effect of the design of take-over requests on drivers’ visual attention alongside take-over times.
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| 26. |
- Prytz, Erik, 1985-, et al.
(författare)
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Fixation Differences in Visual Search of Accident Scenes by Novices and Expert Emergency Responders
- 2018
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Ingår i: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 60:8, s. 1219-1227
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Tidskriftsartikel (refereegranskat)abstract
- Objective:We sought to investigate whether expert–novice differences in visual search behavior found in other domains also apply to accident scenes and the emergency response domain.Background:Emergency service professionals typically arrive at accidents only after being dispatched when a civilian witness has called an emergency dispatch number. Differences in visual search behavior between the civilian witness (usually a novice in terms of emergency response) and the professional first responders (experts at emergency response) could thus result in the experts being given insufficient or erroneous information, which would lead them to arrive unprepared for the actual situation.Method:A between-subjects, controlled eye-tracking experiment with 20 novices and 17 experts (rescue and ambulance service personnel) was conducted to explore expert–novice differences in visual search of accident and control images.Results:The results showed that the experts spent more time looking at task-relevant areas of the accident images than novices did, as predicted by the information reduction hypothesis. The longer time was due to longer fixation durations rather than a larger fixation count.Conclusion:Expert–novice differences in visual search are present in the emergency domain. Given that this domain is essential to saving lives and also relies heavily on novices as the first link in the chain of response, such differences deserve further exploration.Application:Visual search behavior from experts can be used for training purposes. Eye-tracking studies of novices can be used to inform the design of emergency dispatch interviews.
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| 27. |
- Rydström, Annie, et al.
(författare)
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Drivers’ Performance in Non-critical Take-Overs From an Automated Driving System—An On-Road Study
- 2023
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Ingår i: Human Factors. - Thousand Oaks, CA : SAGE Publications. - 1547-8181 .- 0018-7208. ; 65:8, s. 1841-1857
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of this semi-controlled study was to investigate drivers’ performance when resuming control from an Automated Driving System (ADS), simulated through the Wizard of Oz method, in real traffic. Background: Research on take-overs has primarily focused on urgent scenarios. This article aims to shift the focus to non-critical take-overs from a system operating in congested traffic situations. Method: Twenty drivers drove a selected route in rush-hour traffic in the San Francisco Bay Area, CA, USA. During the drive, the ADS became available when predetermined availability conditions were fulfilled. When the system was active, the drivers were free to engage in non-driving related activities. Results: The results show that drivers’ transition time goes down with exposure, making it reasonable to assume that some experience is required to regain control with comfort and ease. The novel analysis of after-effects of automated driving on manual driving performance implies that the after-effects were close to negligible. Observational data indicate that, with exposure, a majority of the participants started to engage in non-driving related activities to some extent, but it is unclear how the activities influenced the take-over performance. Conclusion: The results indicate that drivers need repeated exposure to take-overs to be able to fully resume manual control with ease. Application: Take-over signals (e.g., visuals, sounds, and haptics) should be carefully designed to avoid startle effects and the human-machine interface should provide clear guidance on the required take-over actions.
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| 28. |
- Sagberg, Fridulv, et al.
(författare)
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A Review of Research on Driving Styles and Road Safety
- 2015
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 57:No. 7, November 2015, s. 1248- 1275
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Forskningsöversikt (refereegranskat)abstract
- Objective: To outline a conceptual framework for understanding driving style and, based on this, review the state-of-the-art research on driving styles in relation to road safety.Background: Previous research has indicated a relationship between the driving styles adopted by drivers and their crash involvement. However, a comprehensive literature review of driving style research is lacking. Method: A systematic literature search was conducted, including empirical, theoretical and methodological research on driving styles related to road safety. Results: A conceptual framework was proposed where driving styles are viewed in terms of driving habits established as a result of individual dispositions as well as social norms and cultural values. Moreover, a general scheme for categorising and operationalizing driving styles was suggested. On this basis, existing literature on driving styles and indicators was reviewed. Links between driving styles and road safety were identified and individual and socio-cultural factors influencing driving style were reviewed. Conclusion: Existing studies have addressed a wide variety of driving styles, and there is an acute need for a unifying conceptual framework in order to synthesise these results and make useful generalisations. There is a considerable potential for increasing road safety by means of behaviour modification. Naturalistic driving observations represent particularly promising approaches to future research on driving styles. Application: Knowledge about driving styles can be applied in programmes for modifying driver behaviour and in the context of usage-based insurance. It may also be used as a means for driver identification and for the development of driver assistance systems.
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| 29. |
- Smith, Kip, et al.
(författare)
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Driver Acceptance of False Alarms to Simulated Encroachment
- 2010
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Ingår i: HUMAN FACTORS. - : Sage. - 0018-7208. ; 52:3, s. 466-476
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We investigated driver acceptance of alerts to left-turn encroachment incidents that do not produce a crash. If an event that produces a crash is the criterion for a "true" alert, all the alerts we studied are technically false alarms. Our aim was to inform the design of intersection-assist active safety systems. Background: The premise of this study is that it may be possible to overcome driver resistance to alerts that are false alarms by designing systems to issue alerts when and only when drivers would expect and accept them. Method: Participants were passengers in a driving simulator that presented left-turn encroachment incidents. Participant point of view, the direction of encroachment, and postencroachment time (PET) were manipulated to produce 36 near-crash incidents. After viewing each incident, the participant rated the relative acceptability of a hypothetical alert to it. Results: Repeated-measures ANOVA and logistic regression indicate that acceptability varies inversely with PET. At PET intervals less than 2.2 s, driver point of view and encroachment direction interact. At PET intervals more than 2.2 s, alerts to lateral encroachments are more acceptable than alerts to oncoming encroachments. Conclusion: Driver acceptance of alerts by active safety systems will be sensitive to context. Application: This study demonstrates the utility of eliciting subjective criteria to inform system design to match driver (user) expectations. Intersection-assist active safety systems will need to be designed to adapt to the interaction of driver point of view, the direction of encroachment, and PET.
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| 30. |
- Solis Marcos, Ignacio, et al.
(författare)
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Performance of an Additional Task During Level 2 Automated Driving : An On-Road Study Comparing Drivers With and Without Experience With Partial Automation
- 2018
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Ingår i: Human Factors. - : Sage Publications. - 0018-7208 .- 1547-8181. ; 60:6, s. 778-792
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the influence of prior experience with Level 2 automation on additional task performance during manual and Level 2 partially automated driving.Background: Level 2 automation is now on the market, but its effects on driver behavior remain unclear. Based on previous studies, we could expect an increase in drivers’ engagement in secondary tasks during Level 2 automated driving, but it is yet unknown how drivers will integrate all the ongoing demands in such situations.Method: Twenty-one drivers (12 without, 9 with Level 2 automation experience) drove on a highway manually and with Level 2 automation (exemplified by Volvo Pilot Assist generation 2; PA2) while performing an additional task. In half of the conditions, the task could be interrupted (self-paced), and in the other half, it could not (system-paced). Drivers’ visual attention, additional task performance, and other compensatory strategies were analyzed.Results: Driving with PA2 led to decreased scores in the additional task and more visual attention to the dashboard. In the self-paced condition, all drivers looked more to the task and perceived a lower mental demand. The drivers experienced with PA2 used the system and the task more than the novice group and performed more overtakings.Conclusions: The additional task interfered more with Level 2 automation than with manual driving. The drivers, particularly the automation novice drivers, used some compensatory strategies.Applications: Automation designers need to consider these potential effects in the development of future automated systems.
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| 31. |
- Victor, Trent, 1968, et al.
(författare)
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Automation Expectation Mismatch: Incorrect Prediction Despite Eyes on Threat and Hands on Wheel
- 2018
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 60:8, s. 1095-1116
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to understand how to secure driver supervision engagement and conflict intervention performance while using highly reliable (but not perfect) automation. Background: Securing driver engagement—by mitigating irony of automation (i.e., the better the automation, the less attention drivers will pay to traffic and the system, and the less capable they will be to resume control) and by communicating system limitations to avoid mental model misconceptions—is a major challenge in the human factors literature. Method: One hundred six drivers participated in three test-track experiments in which we studied driver intervention response to conflicts after driving highly reliable but supervised automation. After 30 min, a conflict occurred wherein the lead vehicle cut out of lane to reveal a conflict object in the form of either a stationary car or a garbage bag. Results: Supervision reminders effectively maintained drivers’ eyes on path and hands on wheel. However, neither these reminders nor explicit instructions on system limitations and supervision responsibilities prevented 28% (21/76) of drivers from crashing with their eyes on the conflict object (car or bag). Conclusion: The results uncover the important role of expectation mismatches, showing that a key component of driver engagement is cognitive (understanding the need for action), rather than purely visual (looking at the threat), or having hands on wheel. Application: Automation needs to be designed either so that it does not rely on the driver or so that the driver unmistakably understands that it is an assistance system that needs an active driver to lead and share control.
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| 32. |
- Weibull, Kajsa, et al.
(författare)
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False Alarm Effects in Early Warnings for Emergency Vehicles: Exploring Drivers Move-Over Behavior
- 2023
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Ingår i: Human Factors. - : SAGE PUBLICATIONS INC. - 0018-7208 .- 1547-8181.
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study investigated drivers move-over behavior when receiving an Emergency Vehicle Approaching (EVA) warning. Furthermore, the possible effects of false alarms, driver experience, and modality on move-over behavior were explored. Background: EVA warnings are one solution to encourage drivers to move over for emergency vehicles in a safe and timely manner. EVA warnings are distributed based on the predicted path of the emergency vehicle causing a risk of false alarms. Previous EVA studies have suggested a difference between inexperienced and experienced drivers move-over behavior. Method: A driving simulator study was conducted with 110 participants, whereof 54 inexperienced and 56 experienced drivers. They were approached by an emergency vehicle three times. A control group received no EVA warnings, whereas the experimental groups received either true or false warnings, auditory or visual, 15 seconds before the emergency vehicle overtook them. Results: Drivers who received EVA warnings moved over more quickly for the emergency vehicle compared to the control group. Drivers moved over more quickly for each emergency vehicle interaction. False alarms impaired move-over behavior. No difference in driver behavior based on driver experience or modality was observed. Conclusion: EVA warnings positively affect drivers move-over behavior. However, false alarms can decrease drivers future willingness to comply with the warning. Application: The findings regarding measurements of delay can be used to optimize the design of future EVA systems. Moreover, this research should be used to further understand the effect of false alarms in in-car warnings.
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| 33. |
- Werneke, Julia, 1982, et al.
(författare)
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Perfect Timing: Urgency, Not Driving Situations, Influence the Best Timing to Activate Warnings
- 2014
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Ingår i: Human Factors. - : SAGE Publications. - 1547-8181 .- 0018-7208. ; 56:2, s. 249-259
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of the study was to investigate the influence of different driving scenarios (urban, rural, highway) on the timing required by drivers from a two-stage warning system, based on car-to-car communication.Background: Car-to-car communication systems are designed to inform drivers of potential hazards at an early stage, before they are visible to them. Here, questions arise as to how drivers acknowledge early warnings and when they should be informed (first stage) and warned (second stage). Hence, optimum timing for presenting the information was tested.Method: A psychophysical method was used to establish the optimum timing in three driving scenarios at different speed limits (urban: 50 km/h, rural: 100 km/h, highway: 130 km/h). A total of 24 participants (11 female, 13 male;M = 29.1 years, SD = 11.6 years) participated in the study.Results: The results showed that the optimum timing did not differ among the three scenarios. The first and second stages should ultimately be presented at different timings at each speed limit (first stage: 26.5 s, second stage: 12.1 s before a potential hazard).Conclusion: The results showed that well-selected timing for activating information and warning is crucial for the acceptance of these systems. Appropriate timing for presenting the information and warning can be derived for these systems.Application: The findings will be integrated in further development of assistance systems based on car-to-x technology within the Car2X-Safety project of the Niedersächsisches Forschungszentrum Fahrzeugtechnik in Germany. This study was also supported by Chalmers University of Technology in Sweden.
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| 34. |
- Dekker, Sidney
(författare)
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Doctors are more dangerous than gun owners: A rejoinder to error counting
- 2007
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Ingår i: Human Factors. - 0018-7208. ; 49:2, s. 177-184
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This paper analyzes some of the problems with error counting as well as the difficulty of proposing viable alternatives. Background: Counting and tabulating negatives (e.g., errors) are currently popular ways to measure and help improve safety in a variety of domains. They uphold an illusion of rationality and control but may offer neither real insight nor productive routes for improving safety. Method: The paper conducts a critical analysis of assumptions underlying error counting in human factors. Results: Error counting is a form of structural analysis that focuses on (supposed) causes and consequences; it defines risk and safety instrumentally in terms of minimizing negatives and their measurable effects. In this way, physicians can be proven to be 7500 times less safe than gun owners, as they are responsible for many more accidental deaths. Conclusion: The appeal of error counting may lie in a naive realism that can enchant researchers and practitioners alike. Supporting facts will continue to be found by those looking for errors through increasingly refined methods. Application: The paper outlines a different approach to understanding safety in complex systems that is more socially and politically oriented and that places emphasis on interpretation and social construction rather than on putatively objective structural features.
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| 35. |
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| 36. |
- Källhammer, Jan-Erik, et al.
(författare)
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Driver acceptance of pedestrian alerts by a night vision system
- 2011
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Ingår i: Human Factors. - 0018-7208.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Objective: We investigated driver acceptance of alerts to pedestrian alerts issued by a night vision active safety system with pedestrian detection functionality using a method that leverages scarce and expensive field operational test data. Background: Driver acceptance of automotive active safety systems is a key factor to promote system use and implies a need for a method to assess factors influencing driver acceptance. Method: In a field operational test, ten drivers drove instrumented vehicles equipped with a preproduction night vision system with pedestrian detection software. In a follow-up experiment, the 10 drivers and 25 additional volunteers without experience with the system watched 57 clips with pedestrian encounters gathered during the field operational test. They rated the acceptance of an alert to each pedestrian encounter. Results: Levels of rating concordance were significant between drivers who experienced the encounters and participants who did not. Two contextual variables, pedestrian location and motion, were found to influence ratings. Conclusion: The subjective acceptance rating method provides consistent measures of acceptance in a controlled environment and makes it possible to leverage expensive field operational test data within the confines of the laboratory. Application: The study identifies sources of contextual sensitivity to alerts issued by an active safety system and demonstrates the utility of using subjective driver acceptance criteria to inform active safety system design.
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| 37. |
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