| 1. |
- Ahlström, Christer, et al.
(författare)
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A gaze-based driver distraction warning system and its effect on visual behaviour
- 2013
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Ingår i: IEEE transactions on intelligent transportation systems (Print). - : Institute of Electrical and Electronics Engineers (IEEE). - 1524-9050 .- 1558-0016. ; 14:2, s. 965-973
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Tidskriftsartikel (refereegranskat)abstract
- Driver distraction is a contributing factor to many crashes; therefore, a real-time distraction warning system should have the potential to mitigate or circumvent many of these crashes. The objective of this paper is to investigate the usefulness of a real-time distraction detection algorithm called AttenD. The evaluation is based on data from an extended field study comprising seven drivers who drove on an average of 4351 ± 2181 km in a naturalistic setting.Visual behavior was investigated both on a global scale and on a local scale in the surroundings of each warning. An increase in the percentage of glances at the rear-view mirror and a decrease in the amount of glances at the center console were found. The results also show that visual time sharing decreased in duration from 9.94 to 9.20 s due to the warnings, that the time from fully attentive to warning decreased from 3.20 to 3.03 s, and that the time from warning to full attentiveness decreased from 6.02 to 5.46 s. The limited number of participants does not allow any generalizable conclusions, but a trend toward improved visual behavior could be observed. This is a promising start for further improvements of the algorithm and the warning strategy.
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| 2. |
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| 3. |
- Ahlström, Christer, et al.
(författare)
-
Considerations when calculating percent road centre from eye movement data in driver distraction monitoring
- 2009
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Ingår i: Proceedings of the Fifth International Driving Symposium on Human Factors in Driver Assessment, Training and Vehicle Design. ; , s. 132-139
-
Konferensbidrag (refereegranskat)abstract
- Percent road center (PRC) is a performance indicator which is sensitive to driver distraction. The original definition of PRC is based on fixation data extracted from eye movement recordings, but it has also been suggested that PRC can be determined directly from the gaze data without segmenting it into saccades and fixations. The primary aim of this paper is to investigate if this is the case.Naturalistic driving data from a small scale field operational test comprising seven vehicles was used in the evaluation. It was found that PRC time traces based on gaze data and fixation data, respectively, were highly similar (correlation coefficient=0.95, average wavelet semblance=0.84) except for an absolute amplitude difference of about 8%. This indicates that the two approaches can be used interchangeably and that the processing step of segmenting gaze data into saccades and fixations can be left out.In addition to this finding, design issues related to the calculation of PRC are investigated. Especially, the impact of gaze cases pointing towards the intersection of the road centre area and the centre rear mirror were investigated. Results lead to conclude that gazes and fixations on the centre rear mirror should be removed from the PRC calculations, as they may negatively influence the correctness of the performance indicator.
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| 4. |
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| 5. |
- Kircher, Katja, 1973-, et al.
(författare)
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Comparison of two eye-gaze based real-time driver distraction detection algorithms in a small-scale field operational test
- 2009
-
Ingår i: Proceedings of the 5th International Driving Symposium on Human Factors in Driver Assessment and Design. ; , s. 16-23
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Konferensbidrag (refereegranskat)abstract
- Driver distraction is a field which has received increasing attention in the last years, especially after it became evident that distraction is a major factor contributing to road casualties. Monitoring, detecting and limiting driver distraction could contribute significantly to improve road traffic safety. With the introduction of novel unobtrusive gaze-tracking systems real-time algorithms based on the driver’s gaze direction can be developed for driver distraction warning systems.The study describes and compares two different algorithms for gaze-based driver distraction detection based on the eye tracking data obtained in a field study. One algorithm relies on the metric “percent road centre” of gaze direction, the other on gaze zones in the vehicle. Results show that both algorithms have potential for detecting driver distraction, but that no effect of the distraction warnings on attention as defined by the algorithms could be observed.
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| 6. |
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| 7. |
- Kircher, Katja, 1973-, et al.
(författare)
-
Distraction and drowsiness - a field study : technical report
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The main goal of the distraction and drowsiness field study was to evaluate a system for detecting driver distraction and drowsiness. This report focuses on the system implementation and the algorithms detecting distraction and drowsiness. A vehicle was instrumented with video cameras, an automatic eye tracker and GPS receivers. Further data were read from the CAN bus of the car. The data were logged continuously with high frequency. The log system operated autonomously. Seven participants drove the vehicle during one month each. During the first ten days a behavioural baseline was collected. Afterwards the warnings were activated, such that the drivers received distraction warnings in form of a vibration in the seat when the algorithm determined that they had looked away from the forward roadway too much. A separate algorithm judged whether the drivers were drowsy or not. Questionnaires were administered on three occasions during the course of the study. No major problems were encountered during the field operational test (FOT), but a number of smaller problems had to be solved. However, in the end of the data collection period the computer installed in the car became more and more unstable, which led to increased data loss.
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| 8. |
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| 9. |
- Kircher, Katja, et al.
(författare)
-
Passering av buss i 30 km/h : utvärdering av säkerhetseffekter i samband med hastighetsgräns 30 km/h vid passering av buss - en simulatorstudie
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A simulator study was conducted to investigate the implementation of a new law which prescribes a speed limit of 30 km/h when passing buses equipped with a 30-sign and flashing lights. It was shown that the drivers follow the rule better when they pass a bus on their own side than when the bus was standing on the opposite side of the road. The slowest mean speeds were found when passing a bus on a road with a speed limit of 70 km/h. The highest speed reduction, however, was found when the posted speed limit was 90 km/h. A bus without signage did not induce the same speed reduction as a bus with signage, which means that the drivers were aware of the meaning of the signage. Driving behaviour showed that the flashing lights are of importance, because the drivers in the study started braking before the 30-sign was readable.
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| 10. |
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| 11. |
- Kircher, Katja, 1973-, et al.
(författare)
-
Results of a field study on a driver distraction warning system
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The main goal of the distraction and drowsiness field study was to evaluate a system for detecting driver distraction and drowsiness. This report focuses on the results of the study, indicating how a distraction warning system influenced glance behaviour. A vehicle was instrumented with an automatic eye tracker and other sensors. Seven participants drove the vehicle during one month each. During the first ten days a baseline was collected. Afterwards the warnings were activated, which involved that the drivers received a vibration in the seat when the algorithm determined that they had looked away from the forward roadway for a too long time. The main finding was that the drivers' gaze behaviour was not influenced much by the distraction warnings. The drivers received distraction warnings at about the same frequency during the treatment and the baseline phase. Performance indicators like "percent road centre" and others did not change from baseline to treatment phase. The average percentage of very long glances decreased slightly in the treatment phase, suggesting that the warning had an effect on the more extreme glance behaviour. There are also indications that the system helped prevent further extended glances away from the road immediately after a warning was issued.
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| 12. |
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| 13. |
- Kircher, Katja, 1973-, et al.
(författare)
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The relationship between glance direction and eye tracking quality based on data from a long-term field study
- 2009
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Ingår i: ITS in Daily Life. - Stockholm.
-
Konferensbidrag (refereegranskat)abstract
- It has been shown that distraction is a major factor contributing to road casualties. Detecting and limiting driver impairment could improve road safety. With the introduction of unobtrusive gaze-tracking systems gaze based real-time algorithms can be developed for driver state monitoring.The data reported here stem from an extended field study, during which seven drivers used an instrumented car for one month each. Eye tracking quality is best when the gaze is directed to the road center. The head tracking data show a bimodal distribution, which is interpreted as the drivers’ leaning the head against the head rest at times.
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| 14. |
- Kircher, Katja, et al.
(författare)
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The relationship between glance direction and eye tracking quality based on data from a long-term field study
- 2009
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Ingår i: ITS World Congress 2009, Stockholm, Sweden.
-
Konferensbidrag (refereegranskat)abstract
- Automatic eye tracking is one feasible approach to assess driver state. The technique has matured considerably in recent years, and here automatic eye tracking is even used in a long-term field study. The aim of this study is to investigate whether there is a systematic relationship between gaze direction, head direction and the gaze quality. Gaze and head direction data was acquired with a two camera SmartEye Pro system from seven drivers who drove an instrumented vehicle for one month each. It was found that the quality of the tracking is best when the driver’s gaze is directed at the road centre. Intermediate eye tracking quality was measured for glances to the rear view mirrors and the middle console.The head is generally not moved as much as the eyes and head direction data is more concentrated to the centre region as compared to eye gaze. If gazes to areas like the middle console need to be tracked well, camera position has to be adapted.
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| 15. |
- Ahlström, Christer, et al.
(författare)
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Performance of a one-camera and a three-camera system
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Driving and operating a vehicle is to a great extent a visual task. In driver behaviour studies it is therefore important to be able to measure where the driver is looking. Today this can be done unobtrusively and remotely in real-time with camera based eye tracking. The most common remote eye tracking systems use multiple cameras in order to give satisfactory results. However, promising results using only one camera has recently emerged on the market. The main objective of this study is to compare eye tracking systems with one and three cameras, respectively, during various measurement conditions.A total of 53 participants were enrolled in the study. Data from the two eye trackers were acquired and analysed in terms of availability, accuracy and precision. The results indicate that both availability and accuracy are affected by many different factors. The most important factors are the number of cameras that is used and the angular distance from straight ahead. In the central region (straight ahead) both one-camera and three-camera systems have a high degree of accuracy and availability, but with increasing distance from the central region, the results deteriorate. This effect falls harder upon the one-camera system. Interestingly, there were no significant effects when wearing glasses in either availability or accuracy. There was however an interaction effect between distance and glasses.Advantages with a one-camera system are that it is cheaper, easier to operate and easier to install in a vehicle. A multi-camera system will, on the other hand, provide higher availability and accuracy for areas that are far from the road centre. A one-camera system is thus mostly suitable for in-vehicle applications such as systems that warn drivers for sleepiness or distraction while multi-camera solutions are preferable for research purposes.
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| 16. |
- Amantini, Aladino, et al.
(författare)
-
Initial plan of dissemination and use of results
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This document contains the initial plan for using and disseminating knowledge and foreground developed within the ITERATE Project.The Deliverable contains five main Chapters and an Appendix.The first Chapter describes the purpose of the document, its structure, and introduces the other sections. Chapter 2 and 3 define the dissemination strategy of the ITERATE project and provide a classification of dissemination activities. For each type of dissemination action, the corresponding implementation approach is proposed. Then, for each type of dissemination activity, the actions already performed and those planned are described in some details. The dissemination materials already produced by the project and their usage are briefly described. Materials and products already completed, as well as planned, are described, even though a dedicated Deliverable is foreseen in the future that will contain copies of the actual products provided for dissemination purposes. The Exploitation plan is discussed in the last Chapter of the Deliverable. The two different natures and typology of partners , i.e., academic and industrial/consultancy, are considered. In particular, for each partner, a market and competition analysis is performed and the objectives and guidelines for subsequent exploitation of the results is preliminarily discussed. Finally, the appendix contains, for completeness, the Dissemination and Exploitation Questionnaire utilised to collect information among partners.
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| 17. |
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| 18. |
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| 19. |
- Anund, Anna, et al.
(författare)
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The effect of milled rumble strips versus virtual rumble strips on sleepy drivers : a driving simulator study
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the EU project IN-SAFETY is to create effective combinations of traditional infrastructure measures combined with new technology to increase the self-explanatory and forgiving nature of the road traffic system. This report describes the method, results and conclusions of a driving simulator experiment with the aim to evaluate the effect of two scenarios of importance selected on a theoretical framework within IN-SAFETY: lane departure warning in terms of milled rumble strips or as a driver support system, and the effect of an in-vehicle warning system informing there is a school bus ahead, simulating a system based on vehicle to vehicle information. Concerning the "lane departure warning", the experiment considered possibilities and consequences of replacing the infrastructure element milled rumble strips with a haptic in-vehicle system. Both centre and side line rumble strips on a two-lane highway were studied and compared with a baseline. In-vehicle "School bus ahead warning" was considered as an example of in-vehicle information used to inform the driver of upcoming events. Both rumble strips and school bus warning was studied for drivers after not having slept the night before driving as well as after a night's sleep in order to investigate consequences of driver state on system effectiveness. The results showed that there is a potential to substitute the infrastructure measure rumble strips with an in-vehicle assistance system. Moreover, in-vehicle information was found to be an effective way of reducing the subjects' speeds during temporary critical situations concerning traffic safety.
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| 20. |
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| 21. |
- Anund, Anna, et al.
(författare)
-
The effects of driving situation on sleepiness indicators after sleep loss : A driving simulator study
- 2009
-
Ingår i: Industrial Health. - : National Institute of Industrial Health. - 0019-8366 .- 1880-8026. ; 47:4, s. 393-401
-
Tidskriftsartikel (refereegranskat)abstract
- Almost all studies of sleepy driving are carried out in driving simulators and with monotonous road conditions (no interaction with other cars). The present study investigated indicators of sleepy driving in a more challenging scenario after a night awake. 17 participants drove a high fidelity moving base driving simulator experiment while sleepiness was monitored physiologically and behaviourally. Short periods of situations of free driving (no other vehicles) alternated with short periods of following another vehicle (car following) with and without the possibility to overtake. The result showed that a night of prior sleep loss increased sleepiness levels at the wheel (eye closure duration and lateral variability) compared to after a night of normal sleep. Blink duration while overtaking was significantly lower compared to the other situations, it was at the same level as after night sleep. Speed when passing a stopped school bus was not significantly affected by sleepiness. However the warning caused a more rapid reduction of speed. In conclusion, a moderately challenging driving contest did not affect sleepiness indicators, but a very challenging one did so (overtaking). This suggests that it is important to monitor the driving situation in field operational tests of sleepy driving.
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| 22. |
- Barnard, Yvonne, et al.
(författare)
-
Selection of operator support systems across modes
- 2010
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This Deliverable provides an outline of the process involved in task 2.2 of the ITERATE project forselecting an appropriate set of hypotheses to be tested inWorkpackages 3 (Experimental design andscenario specification), and 4 (Experimental studies).During a workshop with all partners involved in the project, hypotheses were formulated for thethree main system functionalities outlined in D2.1: those that support speed management (SpeedManagement), systems that support system object detection and avoidance (Collision Avoidance)and those that monitor operator state (Operator State). In formulating these hypotheses, partnerswere encouraged to consider systematically the effect of operator state and different operatorgroups on interaction with these three systems. To allow succinct formulation of hypotheses, fouroperator based parameters which are thought to affect operator behaviour with the system, wereidentified: sensation-seeking, hazard perception, fatigue and (high and low) task demand. Informulating hypotheses, partnerswere encouraged to consider the whole process linking a cause toan effect, with a clear mechanism that would link the two.
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| 23. |
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| 24. |
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| 25. |
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| 26. |
- Eriksson, Alexander, et al.
(författare)
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Can user-paced, menu-free spoken language interfaces improve dual task handling while driving?
- 2014
-
Ingår i: Human-Computer Interaction. Advanced Interaction Modalities and Techniques. - Cham : Springer. ; , s. 394-405, s. 394-405
-
Konferensbidrag (refereegranskat)abstract
- The use of speech-based interaction over traditional means of interaction in secondary tasks may increase safety in demanding environments with high requirements on operator attention. Speech interfaces have suffered from issues similar to those of visual displays, as they often rely on a complex menu structure that corresponds to that of visual systems. Recent advances in speech technology allow the use of natural language, eliminating the need for menu structures and offering a tighter coupling between the intention to act and the completion of the action. Modern speech technology may not only make already existing types of interaction safer, but also opens up for new applications, which may enhance safety. One such application is a speech-based hazard reporting system. A small fixed-base simulator study showed that drivers adapt the timing of the hazard reports to the situation at hand, such that an increase in reported workload was avoided.
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| 27. |
- Hilbert, Kevin, et al.
(författare)
-
Cortical and Subcortical Brain Alterations in Specific Phobia and Its Animal and Blood-Injection-Injury Subtypes: A Mega-Analysis From the ENIGMA Anxiety Working Group.
- 2024
-
Ingår i: The American Journal of Psychiatry. - 1535-7228. ; 181:8, s. 728-740
-
Tidskriftsartikel (refereegranskat)abstract
- Specific phobia is a common anxiety disorder, but the literature on associated brain structure alterations exhibits substantial gaps. The ENIGMA Anxiety Working Group examined brain structure differences between individuals with specific phobias and healthy control subjects as well as between the animal and blood-injection-injury (BII) subtypes of specific phobia. Additionally, the authors investigated associations of brain structure with symptom severity and age (youths vs. adults).Data sets from 31 original studies were combined to create a final sample with 1,452 participants with phobia and 2,991 healthy participants (62.7% female; ages 5-90). Imaging processing and quality control were performed using established ENIGMA protocols. Subcortical volumes as well as cortical surface area and thickness were examined in a preregistered analysis.Compared with the healthy control group, the phobia group showed mostly smaller subcortical volumes, mixed surface differences, and larger cortical thickness across a substantial number of regions. The phobia subgroups also showed differences, including, as hypothesized, larger medial orbitofrontal cortex thickness in BII phobia (N=182) compared with animal phobia (N=739). All findings were driven by adult participants; no significant results were observed in children and adolescents.Brain alterations associated with specific phobia exceeded those of other anxiety disorders in comparable analyses in extent and effect size and were not limited to reductions in brain structure. Moreover, phenomenological differences between phobia subgroups were reflected in diverging neural underpinnings, including brain areas related to fear processing and higher cognitive processes. The findings implicate brain structure alterations in specific phobia, although subcortical alterations in particular may also relate to broader internalizing psychopathology.
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| 28. |
- Kircher, Albert, 1975, et al.
(författare)
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Behaviour of deck officers with new assistance systems in the maritime domain
- 2011
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Ingår i: HFES - Human Factors and Ergonomics Society Europe Chapter Conference. October 19-21, 2011, Leeds, UK.
-
Konferensbidrag (refereegranskat)abstract
- The maritime domain is seeing new developments in systems aimed at increasing safety and efficiency of transport. These systems are tested for norm compliance and technical capability, but human factor aspects are not always part of the evaluation. The article argues that this is required, and exemplifies factors of interest with data from a simulator study. Two new systems related to collision warning and speed management were tested on 32 participants in full mission bridge simulators. The factors of main interest were the officers' experience, attitudes and workload. Data on the officers' behaviour were collected for complete runs and for different events related to possible collisions for the one system, and areas where speed should be limited for the second system. Differences in the officers' behaviour were observed in relation to several variables. The study claims that in addition to ensuring the technical capability of systems, a number of human factor issues have to be taken into account. Important aspects of the evaluation are highlighted.
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| 29. |
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| 30. |
- Kircher, Albert, et al.
(författare)
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Knowledge representation forms for data mining methodologies as applied in thoracic surgery
- 2000
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Ingår i: AMIA,2000. - Philadelphia : Hanley & Belfus Inc. - 156053480X ; , s. 428-432
-
Konferensbidrag (refereegranskat)abstract
- Typical ways of disseminating and using results of clinical research are scientific journals and reports. Presentation forms are condensed and comprehensible mainly to the experts following the specific topics. A vast amount of information remains unutilized due to the complex form of presenting the knowledge. Subject of this research is to explore possibilities of representation and also visualization of the results obtained using data mining methodologies. The intention is to formulate more than scientific ways to communicate facts that are of interest for the clinicians, medical students and even patients. Internet technologies as already widely established media support knowledge representation forms such as hypertext documents and structured knowledge components. The "Assist Me" decision support system for surgical treatment of cardiac patients integrates several forms of data mining and representation methodologies. We are showing a feasibility study in which scientific outcomes were forwarded to a broad group of potential users.
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| 31. |
- Kircher, Albert, et al.
(författare)
-
Mobile telephone simulator study
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The study consists of four separate experiments conducted in the VTI drivingsimulator. The common theme was to investigate how driver behaviour andtraffic safety are influenced when the driver attends to another technicaldevice while driving. The experiments were concerned with handsfree orhandheld mobile phone conversation and dialling, receiving mobile phone SMSmessages and watching a DVD film (the latter two being minor pilotexperiments). In three of the experiments (mobile phone conversation, SMS,DVD) the participants drove a route which led through urban and ruralenvironments, ranging from 90 km/h rural to 50 km/h urban environments. Theurban environments differed in complexity (three levels). The drivingdistance was about 70 km. The dialling experiment used a rural environmentwith a speed limit of 110 km/h. The driving distance was about 15 km. In themain experiment dealing with mobile phone conversation, a number of drivingperformance measures were analysed: driving speed, variation in lateralposition, deceleration, brake reaction time, headway, time to collision, etc.PDT (Peripheral Detection Task) was used as a measure of mental workload.Mobile phone conversation was found demanding in terms of mental workload. Italso had effects on driving. Most effects were quite similar for the twophone modes (handsfree, handheld). Impaired reaction time performance wasdemonstrated in one of the situations for handheld mode. However, effectswere found which could be interpreted as attempts to compensate for theincreased workload caused by the mobile phone conversation: speed was reduced(more so for handheld than for handsfree mode), and time and distance headwayincreased. In spite of these compensatory behaviours, mental workload wasstill markedly increased by phone use. In the SMS experiment the participantsbraked later in one situation when reading the SMS message. No other effectswere found in this minor experiment. In the DVD experiment, mental workloadincreased when watching the film, although this was compensated for to someextent by the increased distance headway to a lead vehicle. No compensationin terms of reduced driving speed, however, was apparent in this experiment.In the dialling experiment negative effects on traffic safety were evidentfrom the larger variance of lateral car position during the dialling task forthe handsfree phone mode. The mental workload also increased with thedialling task. Compensation in terms of reduced driving speed was apparentfor both phone modes. Other aspects of mobile phone use while driving stillremain to be analysed in more detail, such as starting or finishing a call,looking for a phone number to dial, mishaps like dropping the phone, etc.
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| 32. |
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| 33. |
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| 34. |
- Kircher, Albert, 1975, et al.
(författare)
-
Performance of Seafarers During Extended Simulation Runs
- 2011
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Ingår i: RINA - Human Factors in Ship Design and Operation.
-
Konferensbidrag (refereegranskat)abstract
- The term “good seamanship” is often used to describe the behaviour of deck officers who navigate according to a commonly accepted set of norms. Even though these norms offer a certain flexibility, most of them are covered by laws and regulations. The navigation performance of deck officers is also of interest, and it could be argued that there is a connection between the terms. For training and evaluation of deck officers an objective assessment of performance is also of great advantage. The scope of the paper is to analyse how different measures can be used to describe navigation performance, and the relationship between these in different collision situations. During an extended simulator study with 50 deck officers, navigation performance was assessed while participants spent one complete week in navigation simulators. Their task was a realistic 24/7 voyage through the English Channel, and each participant spent 64 or 90 hours in the simulator.
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| 35. |
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| 36. |
- Kircher, Albert, et al.
(författare)
-
Vehicle control and drowsiness
- 2002
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The report consists of two parts. The first part is a literature study aimed at identifying the most relevant indicators for predicting and detecting fatigue induced impaired driving. The aim was to identify possible performance based technologies, such as the lateral control of the car. Thus, less attention was devoted to e.g. psycho-physiological measures like EEG. A large number of research reports describing various approaches have been reviewed. The survey clearly indicates that no single indicator can be used to detect drowsy driving.A combination of different measures is recommended e.g. analysis of lateral control performance and eye blink pattern. Furthermore, it should be noted that so far there is no commercial system available that provides a sufficiently reliable method to detect a drowsy driver. In the second part, experimental data from previous driving simulator experiments were analysed by means of signal processing and statistical analyses. Specific attention was paid to investigate the potential of lateral vehicle position data as a mean to estimate driver drowsiness. The analysis of experimental data did not reveal any clear answer to what indicators are the most prominent with respect to detect drowsy driving behaviour. Further investigations and analyses of driving behaviour data are needed. However, the data analysis conforms in large to the findings in the literature survey.
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| 37. |
- Kircher, Albert, 1975, et al.
(författare)
-
Vehicle control and drowsiness
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- It is known that drivers' drowsiness and fatigue is accompanied by deteriorated vehicle control. Albert Kircher, VTI, and Marcus Uddman and Jesper Sandin, Virtual Technology, have investigated which factors are possible to use for the prediction and detection of fatigue induced impaired driving. In this study focus was on variables directly related to lateral control and steering behaviour aiming at a method capable of detection and prediction of impaired driving performance in real time and in an automated manner. Psycho-physiological variables, subjective rating scales, etc. are only briefly discussed. The first part of the report is a literature study. It served to examine the available knowledge in the field and to identify the most promising indicators of impaired driving. A large number of publications describing various approaches have been reviewed. The survey clearly indicates that no single indicator can be used to reliably detect drowsy driving. A combination of different measures is recommended, e.g. analysis of lateral control performance and eye blink patterns. Furthermore, it should be noted that even though there are a small number of commercial drowsiness detection systems available, no system provides a sufficiently reliable and scientifically proven method to detect a drowsy driver. In the second part of the report experimental data from previous driving simulator experiments were analysed. Signal processing techniques, such as frequency analysis by means of Fourier transforms, and statistical analyses were used to disclose if data could be used to determine drivers' drowsiness as rated on subjective rating scales (Karolinska Sleepiness Scale). Specific attention was paid to investigate the potential of lane control data (steering performance) as a mean to estimate driver drowsiness. Measures related to lateral vehicle position, such as time to line crossing and deviation of lateral position, were also analysed, but were not found useful. The analysis of experimental data did not reveal any clear answer to what driver behaviour indicators are the most prominent to detect drowsy driving behaviour. However, the data analysis conforms in large to the findings in the literature survey: a single variable is hardly usable as drowsiness predictor. More advanced signal processing techniques could be more proficient for the aspired goal. Further investigations and analyses of driving behaviour data are needed. Combination of different variables, such as eye blink patterns and lane control measures, are expected to be more successful.
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| 38. |
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| 39. |
- Linder, Astrid, et al.
(författare)
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Intelligent Transport Systems (ITS) in passenger cars and methods for assessment of traffic safety impact : a literature review
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The background for this study is that many Intelligent Transport Systems (ITS) are currently introduced in passenger vehicles aiming at providing increased traffic safety. This provides a need to assess the traffic safety effects from these systems. The question that this report highlights is how these systems are designed and how the effects are evaluated. The review resulted in identification of 300 references of which the most relevant are found in this report. The report contains a description of the background of why and how 20 systems or groups of systems have been developed, in which vehicles they can be found, a short technical description of how they work, publication of traffic safety effects and future development plans. Regarding statistical methods, an overview of how they work and the results when using these methods on ITS are described. In addition, the report contains a summary of ways of assessing safety effects from areas such as food, nuclear power and pharmaceutical industries. The conclusion is that there are currently many different ways of supporting the driver in the task of driving the vehicle. Regarding the impact on traffic safety of these systems it is still an open question which evaluation methods to use.
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| 40. |
- Lützhöft, Margareta, et al.
(författare)
-
Fatigue at sea : a field study in Swedish shipping
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this study was to collect data about the fatigue level of bridge watch keepers to use for revising earlier sleep models, and devise innovative solutions for the shipping industry. Data collection included interviews with shipping companies and a field study onboard 13 cargo vessels. 32 participants took part in representing two watch systems; 2-watch and 3-watch. Subjective sleepiness and stress estimations were performed once every hour. Electrooculography was used to record eye movement behaviour. Reaction time test was made to examine performance. 3-watch participants are more satisfied with their working hours and working situation. Tendencies indicate that 2-watch participants are a bit more tired, whereas the stress is the same. All are less sleepy and less stressed at home. Time on shift had effect on sleepiness. The highest Karolinska Sleepiness Scale scores were recorded in the late night and early morning. After night shift the reaction times have higher variance and more long reaction times are present. The mean value after night shift was significantly higher than after day shift. All thirteen shipping agreed that officers on the bridge always have tasks sensitive to fatigue but no company experienced fatigue as a problem during normal conditions. All were positive to monitoring devices, mentioning safety matters.
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| 41. |
- Lützhöft, Margareta, 1964, et al.
(författare)
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Fatigue at Sea: A field study in Swedish shipping
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this study was to collect data about the fatigue level of bridge watch keepers to use for revising earlier sleep models, and devise innovative solutions for the shipping industry. Data collection included interviews with shipping companies and a field study onboard 13 cargo vessels. 32 participants took part in representing two watch systems; 2-watch and 3-watch. Subjective sleepiness and stress estimations were performed once every hour. EOG was used to record eye movement behaviour. Reaction time test was made to examine performance. 3-watch participants are more satisfied with their working hours and working situation. Tendencies indicate that 2-watch participants are a bit more tired, whereas the stress is the same. All are less sleepy and less stressed at home. Time on shift had effect on sleepiness. The highest KSS scores were recorded in the late night and early morning. After night shift the reaction times have higher variance and more long reaction times are present. The mean value after night shift was significantly higher than after day shift. All thirteen shipping companies agreed that officers on the bridge always have tasks sensitive to fatigue but no company experienced fatigue as a problem during normal conditions. All were positive to monitoring devices, mentioning safety matters.
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| 42. |
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| 43. |
- Lützhöft, Margareta, 1964, et al.
(författare)
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Fatigue at Sea in Swedish Shipping-A Field Study
- 2010
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Ingår i: American Journal of Industrial Medicine. - : Wiley. - 0271-3586 .- 1097-0274. ; 53:7, s. 733-740
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Tidskriftsartikel (refereegranskat)abstract
- Background Today many merchant ships sail with only two nautical officers, working a shift schedule of 6 hr on and 6 hr off There are concerns that such a shift schedule is related to fatigue. However, little data exist from onboard studies of seafarers. Methods Data were collected on board 13 ships. Fifteen participants worked on a 6-on, 6-off watch system. and another 15 on a 4-on, 8-off watch system. Electrooculography, actigraphy, diaries, and reaction time tests were used to measure the effects of shift system on fatigue and sleep. Results and Conclusions Sleepiness was higher during the night shift in the 6-on, 6-off system. Moreover, sleepiness increased more during the watch in the 6-on, 6-off system compared to the 4-on, 8-off system. There was a trend toward shorter sleep episodes in the 6-on, 6-off system and sleep was more often split into two episodes.
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| 44. |
- Patten, Christopher, 1968-, et al.
(författare)
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Driver experience and cognitive workload in different traffic environments.
- 2006
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Ingår i: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575 .- 1879-2057. ; 38:5, s. 887-894
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Tidskriftsartikel (refereegranskat)abstract
- How do levels of cognitive workload differ between experienced and inexperienced drivers? In this study we explored cognitive workload and driver experience, using a secondary task method, the peripheral detection task (PDT) in a field study. The main results showed a large and statistically significant difference in cognitive workload levels between experienced and inexperienced drivers. Inexperienced, low mileage drivers had on average approximately 250 milliseconds (ms) longer reaction times to a peripheral stimulus, than the experienced drivers. It would, therefore, appear that drivers with better training and experience were able to automate the driving task more effectively than their less experienced counterparts in accordance with theoretical psychological models. It has been suggested that increased training and experience may provide attention resource savings that can benefit the driver in handling new or unexpected traffic situations.
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| 45. |
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| 46. |
- Patten, Christopher, 1968-, et al.
(författare)
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Using mobile telephones : cognitive workload and attention resource allocation
- 2004
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Ingår i: Accident Analysis and Prevention. - 0001-4575 .- 1879-2057. ; 36:3, s. 341-350
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Tidskriftsartikel (refereegranskat)abstract
- Driver distraction is recognized as being one of the central causes of road traffic incidents and mobile telephones are tangible devices (among many other electronic devices) that can distract the driver through changes in workload. Forty participants completed a motorway route characterized by a low level of road complexity in the form of vehicle handling and information processing. A peripheral detection task (PDT) was employed to gauge mental workload. We compared effects of conversation type (simple versus complex) and telephone mode (hands-free versus handheld) to baseline conditions. The participants' reaction times increased significantly when conversing but no benefit of hands-free units over handheld units on rural roads/motorways were found. Thus, in regard to mobile telephones, the content of the conversation was far more important for driving and driver distraction than the type of telephone when driving oil a rnotorway or similar type of road. The more difficult and complex the conversation, the greater the possible negative effect on driver distraction. (C) 2003 Elsevier Ltd. All rights reserved.
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| 47. |
- Rigaud, Eric, et al.
(författare)
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Impact: More Than Maritime Risk Assessment
- 2012
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Ingår i: Procedia - Social and Behavioral Sciences. - : Elsevier BV. - 1877-0428. ; 48, s. 1848-1854
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Tidskriftsartikel (refereegranskat)abstract
- The development of a new technology, the definition of a new regulation or an organisational change aims to increase a positive performance (i.e. safety and cost effectiveness) or decrease a negative performance (i.e. occurrence of accidents or workload) in a system. However, change can also be the origin of consequences that have not been anticipated during the design phase. Such consequences can be positive, negative or damaging for the system. Consequently, an assessment phase is often integrated into technical, regulatory or organisational design activities. This assessment phase is generally structured with hazard identification and risk assessment steps that are followed by a cost benefit analysis and formulation of recommendations. The IMPACT project aims to extend the scope of the hazard identification phase generally based on traditional failure analysis methods (i.e. FMEA, THERP) by integrating stakeholder expertise and applying resilience engineering approaches of safety management. The project has also tested the possibility to use a cluster of bridge simulators together with a system for data collection and visualization in order to explore the consequences of change in maritime settings.
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| 48. |
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| 49. |
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| 50. |
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