| 1. |
- Ahlström, Christer, 1977-, et al.
(författare)
-
The impact of driver sleepiness on fixation-related brain potentials
- 2020
-
Ingår i: Journal of Sleep Research. - : Wiley. - 0962-1105 .- 1365-2869. ; 29:5
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of driver sleepiness are often quantified as deteriorated driving performance, increased blink durations and high levels of subjective sleepiness. Driver sleepiness has also been associated with increasing levels of electroencephalogram (EEG) power, especially in the alpha range. The present exploratory study investigated a new measure of driver sleepiness, the EEG fixation-related lambda response. Thirty young male drivers (23.6 +/- 1.7 years old) participated in a driving simulator experiment in which they drove on rural and suburban roads in simulated daylight versus darkness during both the daytime (full sleep) and night-time (sleep deprived). The results show lower lambda responses during night driving and with longer time on task, indicating that sleep deprivation and time on task cause a general decrement in cortical responsiveness to incoming visual stimuli. Levels of subjective sleepiness and line crossings were higher under the same conditions. Furthermore, results of a linear mixed-effects model showed that low lambda responses are associated with high subjective sleepiness and more line crossings. We suggest that the fixation-related lambda response can be used to investigate driving impairment induced by sleep deprivation while driving and that, after further refinement, it may be useful as an objective measure of driver sleepiness.
|
|
| 2. |
- Eriksson, Gabriella, 1983-, et al.
(författare)
-
The time-saving bias : Judgements, cognition and perception
- 2013
-
Ingår i: Judgment and decision making. - : Cambridge University Press (CUP). - 1930-2975 .- 1930-2975. ; 8:4, s. 492-497
-
Tidskriftsartikel (refereegranskat)abstract
- Biases in people's judgments of time saved by increasing the speed of an activity have been studied mainly with hypothetical scenarios (Svenson, 2008). The present study asked whether the classic time-saving bias persists as a perceptual bias when we control the speed of an activity and assess the perceived time elapsed at different speeds. Specifically, we investigated the time-saving bias in a driving simulator. Each participant was asked to first drive a distance at a given speed and then drive the same distance again at the speed she or he judged necessary to gain exactly three minutes in travel time compared to the first trip. We found that that the time-saving bias applies to active driving and that it affects the choice of driving speed. The drivers' time-saving judgements show that the perception of the time elapsed while driving does not eliminate the time-saving bias.
|
|
| 3. |
|
|
| 4. |
- Svenson, Ola, et al.
(författare)
-
Judgments of mean speed and predictions of route choice
- 2011
-
Ingår i: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 14:6, s. 504-511
-
Tidskriftsartikel (refereegranskat)abstract
- How are driving speeds integrated when speeds vary along a route? In a first study, we examined heuristic processes used in judgments of mean speed when the mean speeds on parts of the trip varied. The judgments deviated systematically from objective mean speeds because the distances driven at different speeds were given more weight than travel time spent on the different distances. The second study showed that when there was a 10-15 min pause during a travel the effect on the mean speed decrease was underestimated for driving speeds of 90 km/h and higher. In the third study, the objective mean speeds and the subjective biased mean speed judgments were used to predict choices between routes with different speed limits. The results showed that subjective judgments predicted decisions to maximize mean speed significantly better than objective mean speeds. Finally, some applied and basic research implications of the results were discussed.
|
|
| 5. |
- Ahlström, Christer, 1977-, et al.
(författare)
-
Real-Time Adaptation of Driving Time and Rest Periods in Automated Long-Haul Trucking : Development of a System Based on Biomathematical Modelling, Fatigue and Relaxation Monitoring
- 2022
-
Ingår i: IEEE transactions on intelligent transportation systems (Print). - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1524-9050 .- 1558-0016. ; 23:5, s. 4758-4766
-
Tidskriftsartikel (refereegranskat)abstract
- Hours of service regulations govern the working hours of commercial motor vehicle drivers, but these regulations may become more flexible as highly automated vehicles have the potential to afford periods of in-cab rest or even sleep while the vehicle is moving. A prerequisite is robust continuous monitoring of when the driver is resting (to account for reduced time on task) or sleeping (to account for the reduced physiological drive to sleep). The overall aims of this paper are to raise a discussion of whether it is possible to obtain successful rest during automated driving, and to present initial work on a hypothetical data driven algorithm aimed to estimate if it is possible to gain driving time after resting under fully automated driving. The presented algorithm consists of four central components, a heart rate-based relaxation detection algorithm, a camera-based sleep detection algorithm, a fatigue modelling component taking time awake, time of day and time on task into account, and a component that estimates gained driving time. Real-time assessment of driver fitness is complicated, especially when it comes to the recuperative value of in-cab sleep and rest, as it depends on sleep quality, time of day, homeostatic sleep pressure and on the activities that are carried out while resting. The monotony that characterizes for long-haul truck driving is clearly interrupted for a while, but the long-term consequences of extended driving times, including user acceptance of the key stakeholders, requires further research.
|
|
| 6. |
- Andersson, Jan, 1965-, et al.
(författare)
-
The complexity of changes in modal choice : A quasi-experimental study
- 2023
-
Ingår i: Transportation Research Part F. - : Elsevier. - 1369-8478 .- 1873-5517. ; 96:July, s. 36-47
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Changes in modal choice is argued to be one way to reduce the emission of greenhouse gases. Increasing modal choices in favour of more environmentally friendly travel modes requires a better understanding of how these choices are actually made. The first aim of this study is therefore to examine how modal choice is related to subjective experiences as perceived accessibility, perceived satisfaction , habit, both before , after an intervention promoting public transport. The second aim is to examine how modal choice is affected by the intervention. Finally, the third aim is to examine how subjective experiences as perceived accessibility, perceived satisfaction, and habit are affected by the intervention.Method: The design used is a before-and after-study with free public travel passes as the intervention (30-or 14-days free travel pass). Altogether, 52 travelers - distributed on two intervention groups and one control group - participated in the study. The 30-days free travel pass group constitutes 18 participants, the 14-days free travel pass group constitutes 19 participants while the control group constitutes 15 participants. During the before -period the participants were asked to register their modal choice using a digitalized application downloaded on their smart phones (the TravelVu app), to complete a short app-based questionnaire, and a web-based questionnaire. During the after-period, they were once again asked to register their modal choice and to complete a web-based questionnaire. All data collected were analyzed by variance or correlation analyses using the change between before-and after period as the dependent variable.Conclusion: The intervention did not affect the modal choice or the subjective experiences. Over time, the participants did however increase their use of public transport and their cognitive evaluation of their everyday travel overall, while they decreased their use of car and became less reflective and less interested in trying out new alternative travel modes. These changes might be attributed to their participation in the present study.
|
|
| 7. |
- Eriksson, Lars, et al.
(författare)
-
Performance and presence with head-movement produced motion parallax in simulated driving
- 2015
-
Ingår i: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 34, s. 54-64
-
Tidskriftsartikel (refereegranskat)abstract
- Driving simulator studies can reveal relevant and valid aspects of driving behavior, but underestimation of distance and speed can negatively affect the driver's performance, such as in performance of overtaking. One possible explanation for the underestimation of distance and speed is that two-dimensional projection of the visual scene disrupts the monocular-based illusory depth because of conflicting binocular and monocular information of depth. A possible solution might involve the strengthening of the monocular information so that the binocular information becomes less potent.In the present study, we used an advanced high-fidelity driving simulator to investigate whether adding the visual depth information of motion parallax from head movement affects sense of presence, judgment of distance and speed, and performance measures coupled with overtaking. The simulations included two types of driving scenario in which one was urban and the other was rural. The main results show no effect of this head-movement produced motion parallax on sense of presence, head movement, time to collision, distance judgment, or speed judgment.However, the results show an effect on lateral positioning. When initiating the overtaking maneuver there is a lateral positioning farther away from the road center as effect of the motion parallax in both types of scenario, which can be interpreted as indicating use of naturally occurring information that change behavior at overtaking. Nevertheless, only showing tendencies of effects, absent is any clear additional impact of this motion parallax in the simulated driving.
|
|
| 8. |
- Forward, Sonja, et al.
(författare)
-
Polisens attityder till trafikövervakning : en jämförelse mellan år 1999 och år 2007
- 2008
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report is based on the results obtained from two questionnaire studies carried out during 1999 and 2007. The aim of the studies is to increase our knowledge about the attitudes and approach of the police to traffic safety work and how these attitudes have changed with time. In the first study 729 randomly chosen police officers completed the questionnaire and in the second 1,022. The results show that the basic attitude among the police towards traffic surveillance has become more positive. The attitudes towards the directives from the governing bodies and their ability to participate in decision making have improved slightly from the first measurement to the second measurement. However, it is characteristic that a fairly large proportion still is dissatisfied with the same. The attitude of the police towards their own reporting of accidents has not changed appreciably at all. On the other hand, the understanding that a certain amount of statistics shall be reported is slightly greater in 2007 than in 1999. The attitudes towards automatic surveillance have strongly improved although a well-visible policeman is still advocated. The need to reinforce the surveillance of professional traffic is considered to be greater in 2007 than in 1999. According to the police, the attitude amongst the public towards speeding offences has become more negative than it was before. Nevertheless, a relatively high proportion still believes that it is a relatively minor offence. In 2006, the tolerance level for speeding offences was lowered at the same time as the fines for traffic offences were raised markedly. The results of the questionnaire show that the police are neutral towards whether or not these measures will influence the public’s acceptance of the traffic safety work, which could indicate that they have not yet defined their attitude regarding the question. More than half of all police officers in 2007 do not believe that the public are aware of the possibility of having a time for consideration with respect to the acceptance of a fine for a breach of regulations. Finally the results show that in 2007, more controls were carried out than before. The most important conclusions that can be drawn from these results are that the police have developed a more positive attitude towards the traffic safety work and that, at the same time, more traffic controls are being carried out. But there are also many who still do not feel that they are able to influence their work. Furthermore, many are dissatisfied with the governing body’s directives regarding traffic safety work. Such a dissatisfaction can influence the psycho-social work environment and the motivation for carrying out good work, but concretely the results show that such a dissatisfaction influences, both directly and indirectly, how many traffic controls one carries out.
|
|
| 9. |
- Svenson, Ola, et al.
(författare)
-
Different heuristics and same bias : A spectral analysis of biased judgments and individual decision rules
- 2018
-
Ingår i: Judgment and decision making. - : Cambridge University Press (CUP). - 1930-2975 .- 1930-2975. ; 13:5, s. 401-412
-
Tidskriftsartikel (refereegranskat)abstract
- We used correlation and spectral analyses to investigate the cognitive structures and processes producing biased judgments. We used 5 different sets of driving problems to exemplify problems that trigger biases, specifically: (1) underestimation of the impact of occasional slow speeds on mean speed judgments, (2) overestimation of braking capacity after a speed increase, (3) the time saving bias (overestimation of the time saved by increasing a high speed further, and underestimation of time saved when increasing a low speed), (4) underestimation of increase of fatal accident risk when speed is increased, and (5) underestimation of the increase of stopping distance when speed is increased. The results verified the predicted biases. A correlation analysis found no strong links between biases; only accident risk and stopping distance biases were correlated significantly. Spectral analysis of judgments was used to identify different decision rules. Most participants were consistent in their use of a single rule within a problem set with the same bias. The participants used difference, average, weighed average and ratio rules, all producing biased judgments. Among the rules, difference rules were used most frequently across the different biases. We found no personal consistency in the rules used across problem sets. The complexity of rules varied across problem sets for most participants.
|
|
| 10. |
- Svenson, Ola, et al.
(författare)
-
Mental models of driving and speed : biases, choices and reality
- 2017
-
Ingår i: Transport reviews. - : Informa UK Limited. - 0144-1647 .- 1464-5327. ; 37:5, s. 653-666
-
Tidskriftsartikel (refereegranskat)abstract
- This paper provides a review of research performed by Svenson with colleagues and others work on mental models and their practical implications. Mental models describe how people perceive and think about the world including covariances and relationships between different variables, such as driving speed and time. Research on mental models has detected the time-saving bias [Svenson, O. (1970). A functional measurement approach to intuitive estimation as exemplified by estimated time savings. Journal of Experimental Psychology, 86, 204-210]. It means that drivers relatively overestimate the time that can be saved by increasing speed from an already high speed, for example, 90-130km/h, and underestimate the time that can be saved by increasing speed from a low speed, for example, 30-45km/h. In congruence with this finding, mean speed judgments and perceptions of mean speeds are also biased and higher speeds given too much weight and low speeds too little weight in comparison with objective reality. Replacing or adding a new speedometer in the car showing min per km eliminated or weakened the time-saving bias. Information about braking distances at different speeds did not improve overoptimistic judgments of braking capacity, but information about collision speed with an object suddenly appearing on the road did improve judgments of braking capacity. This is relevant to drivers, politicians and traffic regulators.
|
|
