| 1. |
- 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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| 2. |
- Anund, Anna, et al.
(författare)
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The effects of driving situation on sleepiness indicators after sleep loss : A driving simulator study
- 2009
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Ingår i: Industrial Health. - : National Institute of Industrial Health. - 0019-8366 .- 1880-8026. ; 47:4, s. 393-401
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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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| 3. |
- Broberg, Thomas K, 1968, et al.
(författare)
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Safe mobility for elderly drivers-Considerations based on expert and self-assessment
- 2014
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Ingår i: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575 .- 1879-2057. ; 66, s. 104-113
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Tidskriftsartikel (refereegranskat)abstract
- To further understand the needs of the growing population of elderly drivers and create solutions for safe mobility it is important to understand the driving scenarios and aspects in day to day traffic that may be of challenge for this group. More so, individual differences in how drivers perceive their own driving ability may have an effect on how individuals limit their mobility and/or increase their exposure to risk situations, with a potential negative effect on safety. In this study two sets of assessments have been used in order to identify scenarios and aspects needing consideration in creating safe mobility for elderly drivers; an expert assessment using on-road driving together with assessments through semi structured in-depth interviews. This combination also enables categorisation of the drivers, comparing their own perception of their driving performance with the expert assessment based on actual on-road driving. Four different categories of drivers were identified: adequate (positive), over, under and adequate (negative) estimators. A number of important aspects were identified in the study. Adapting speed to the situation and driving too fast, especially on straight roads in the city, is one aspect. Seeking the attention of other road users at intersections and roundabouts is another important consideration identified. Awareness of difficulties related to speed adaptation and attention was low amongst all the driver categories. However, a difference in attitude was seen in the categories with a more humble and acceptant attitude amongst the adequate and under estimator groups, as compared to the over estimators suggesting that the aspect of attitudes is another important factor for consideration. (C) 2014 Elsevier Ltd. All rights reserved.
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| 4. |
- Praetorius, Gesa, 1980-, et al.
(författare)
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Learning lessons in resilient traffic management : A cross-domain study of Vessel Traffic Service and Air Traffic Control
- 2012
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Ingår i: Human Factors : a view from an integrative perspective. - Groningen : HFES Europe Chapter. - 9780945289449 ; , s. 277-287
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Konferensbidrag (refereegranskat)abstract
- Although younger than the maritime domain, aviation has had a huge impact on the system design and development within shipping. Stakeholders often look towards aviation to make shipping, and the way that traffic is handled and organised, safer, more efficient and more effective. Although legally not the same, Vessel Traffic Service (VTS) is frequently compared to Air Traffic Control (ATC). In this article the area of traffic management within the maritime and aviation domains is addressed from a Resilience Engineering perspective. Focus is placed on the arrival part of a mission. The comparison is based on information collected during two study visits at VTS centres and one study visit at an ATC centre. The two organisations are described with the help of the Resilient Engineering capabilities: to respond, to monitor, to anticipate, and to learn. Furthermore, it is discussed how VTS and ATC adapt to cope with the complexity encountered during daily work.
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| 5. |
- Praetorius, Gesa, 1980-, et al.
(författare)
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"Safety is everywhere" : The Constituents of Maritime Safety
- 2011
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Ingår i: Proceedings of the Human Factors and Ergonomics Society, 55th Annual Meeting 2011. - : Sage Publications. ; , s. 1798-1802, s. 1798-1802
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Konferensbidrag (refereegranskat)abstract
- Although maritime safety is one of the key terms in regulation, guidelines and recommendations, such as SOLAS (International Convention for the safety of life at sea (IMO, 1974), in the shipping domain, there is, to the best of our knowledge, neither an explanation of this specific type of safety nor any explicit understanding on how it is promoted by those who work on board of merchant vessel. This qualitative study approaches maritime safety from a crew perspective and discusses what constituents should be considered to be part of maritime safety.
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| 6. |
- Praetorius, Gesa, 1980, et al.
(författare)
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The context matters: Maritime safety in the Vessel Traffic Service (VTS) Domain
- 2010
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Ingår i: Reliability, Risk and Safety. Back to the Future (Proceedings of ESREL 2010). - : CRC Press. - 9780415604277 ; , s. 1773-1780
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Konferensbidrag (refereegranskat)abstract
- Vessel Traffic Service (VTS) is a service to the maritime community implemented to promote and improve maritime safety. In recent years VTS has become a topic of increased interest for maritime stakeholders and the general public. To derive insights on how maritime safety is constructed in the VTS domain this exploratory study was conducted. Four VTS centres were visited and 15 VTS operators were interviewed and observed at work. Further, a focus group interview with 8 VTS operators with focus on decision support tools in the VTS domain was conducted. The results of the study indicate that VTS operators define maritime safety as context-dependent a condition which is formed by their individual actions. Regulations and guidelines exist, but do not shape the daily work of the operators as much as their own experience and expertise. Safety arises in the interaction between the individual actor and others; it is influenced by contextual aspects, such as traffic density or weather conditions, rather than by what is stated by the regulating organisation.
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| 7. |
- Stave, Christina
(författare)
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Safety as a process : From risk perception to safety activity
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The frequency of occupational accidents in the Swedish food industry and agriculture is high. This thesis has therefore explored the 'process of safety' in order to detect and analyse factors that either hinder or facilitate safety activity and to further develop intervention methods towards increased safety activity. The first study was based on in-depth interviews with 54 injured food-industry operators and their supervisors, exploring preconditions of accidents, using the qualitative method of grounded theory. Results showed that the accidents were embedded in the "normal" in which the accidents occurred without any warning. Preconditions of accidents were technical and organisational deficiencies such as insufficient communication and learning, high responsibility in combination with low control, conflicting goals, and a gap between procedures and practice. These factors influenced the safety culture toward risk acceptance and a normalisation of accidents. The second study tested a hypothetical model of the casual relationship between risk perception and safety activity as well as risk acceptance. Results were based on a cross-sectional questionnaire exploring the attitudes towards risk and safety of 315 farmers and farm workers. The results mainly confirmed two paths, one mediated by risk manageability and one by work stress, which counteracted each other The third study was an evaluation of a safety intervention methodology based on group discussions with three levels of structure. Eighty-eight farmers and farm workers divided into 9 groups gathered on seven occasions during one year. A pre-post questionnaire was used to evaluate the effects. The results showed a significant increase in safety activity. Stress as well as risk acceptance were reduced, but risk perception and perceived risk manageability did not change. The fourth study evaluated the process of the intervention. Results indicated good feasibility of the method. The social network was stated to be most beneficial and a time span was needed. The conclusions of the thesis were that the process of safety might benefit from reflecting and discussing incident experiences, detecting hindrances/facilitators to safety. Risk acceptance and normalisation of accidents may be influenced by focusing on work stress and the priority of safety, supporting a participative process of change with an honest climate.
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| 8. |
- Andersson-Sköld, Yvonne, 1957-, et al.
(författare)
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Development of the SUNRA Tool to Improve Regional and Local Sustainability of the Transportation Sector
- 2022
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 14:18, s. 11275-
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Tidskriftsartikel (refereegranskat)abstract
- To fulfil the global sustainable development goals (SDGs), achieving sustainable development is becoming urgent, not least in the transportation sector. In response to this, the sustainability framework Sustainability National Road Administrations (SUNRA) was developed to contribute to improving the sustainability performance of national road administrations across Europe. In the present study, the framework has been tested, applied and further developed to be applicable for target setting and follow-up at the project level at both the Swedish Transport Administration (STA) and at municipal levels. The aim was a framework relevant for investment, re-investments, maintenance and operation projects and also to make it more user applicable. The study also investigated how the framework can contribute to sustainability, identified drivers and barriers for applying the framework and examined whether the framework can be applied and adapted to projects of different complexities. The adaptations and developments were done in collaboration between researchers and practitioners. The results show that the framework could easily be used and adapted for investment, re-investment, maintenance and operation projects in the planning stage, as well as for small municipal establishments, construction or reconstruction of residential areas and frequent maintenance. The framework contributes to increased awareness on sustainability, and it provides a common structure and transparency on how infrastructure project goals/targets are set and fulfilled. The framework can also be applied to follow the fulfilment of the goals/targets and thereby adapt the project to better fulfil the goals. Identified barriers include the lack of obligations and lack of experience in using sustainability frameworks.
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| 9. |
- Berlin, Cecilia, 1981, et al.
(författare)
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Applied Cognitive Task Analysis (ACTA) of marine piloting in a Swedish Context
- 2023
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Ingår i: Human Factors in Transportation. - New York : AHFE International. - 9781958651711 ; 95:2023, s. 709-718
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Konferensbidrag (refereegranskat)abstract
- Modern-day marine pilots are a competent and experienced workforce. They are highly skilled navigators that support the merchant fleet in transiting through challenging sea areas and rivers, as well as in the navigation in and out of ports. In this study, Applied Cognitive Task Analysis (ACTA) was used to pursue a deeper understanding of expertise and tacit or procedural knowledge that experts rely on and exhibit, mostly in safety-critical situations. ACTA is a structured interview method, which relies on three distinct phases: a task diagram, a knowledge audit and a simulation interview. In this article, results from the first two interview steps are presented to show the intricate complexity of pilotage and building blocks of expertise within marine pilotage. A total of eight experienced pilots from two different port areas in Sweden were interviewed. The results show that there are large differences in how pilotage is conducted in the two areas with regards to both tasks, knowledge and understanding of the service as such. Further, despite recognizing maneuvering as cognitively demanding, the pilots emphasized social skills and learning on the job as key elements of expertise. Conclusions drawn from the ACTA structure highlight the mentally and socially complex task that piloting is, and that the pilots use great discernment and acuity when processing verbal and non-verbal input, as well as physical human and vessel movements.
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| 10. |
- Placido da Conceicao, Vitor Fernando, 1970, et al.
(författare)
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Analysing human factors for naval navigation accidents using hfacs
- 2020
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Ingår i: Developments in the Collision and Grounding of Ships and Offshore Structures. - : CRC Press. - 9780367433130 ; , s. 319-327, s. 319-327
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Konferensbidrag (refereegranskat)abstract
- Since the early ’90s the Portuguese Navy has implemented several measures to improve its navigation safety performance, such as new policies, standard operational procedures, auditing and training programs, revision of course programs and certification requirements. Despite this progress, navigation accidents, remain a significant concern for the Portuguese Navy. Moreover, we still need further understanding of the effectiveness of innovative trends in marine technology over navigation safety. This paper presents an analysis of Portuguese’s naval accidents applying an adapted version of the Human Factors Analysis and Classification System-HFACS framework. Twenty navigation accidents cases were considered. The analysis shows that causality factors with higher relevance are the decision and perceptual errors, non-use or misuse of instruments (Environmental factors), BRM (Personnel factors), inadequate leadership and inappropriate planning (Unsafe leadership). These findings provide an essential contribution to the revision of educational and training programs, insights for the design of bridges and navigation aids.
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