| 11. |
- Adell, Emeli, et al.
(author)
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Auditory and haptic systems for in-car speed management – A comparative real life study
- 2008
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In: Transportation Research. Part F: Traffic Psychology and Behaviour. - : Elsevier BV. - 1369-8478. ; 11:6, s. 445-458
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Journal article (peer-reviewed)abstract
- Field experiments with ISA (intelligent speed adaptation) were carried out in Hungary and Spain in 2003 and 2004, respectively. Twenty private vehicles in each country were equipped with two kinds of systems: (1) support via an active accelerator pedal (AAP) and (2) warning via beep signals and a flashing red light when the speed limit was exceeded (BEEP). The test drivers drove for a month with both systems installed in each car. Speed was continually logged in all the vehicles and the test drivers were interviewed about their acceptance and experiences of the systems. The results show that both systems reduced the mean and 85 percentile speeds, but that the AAP was more effective. There was no long-lasting effect on speeds when the systems were removed. After the trial half of the drivers were willing to keep an ISA system, but more drivers wanted to keep the BEEP-system even though it showed lower satisfaction ratings than the AAP. The results indicate no major differences between the countries despite the workload being perceived to be higher in Hungary than in Spain.
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| 12. |
- Adell, Emeli, et al.
(author)
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Driver comprehension and acceptance of the active accelerator pedal after long-term use
- 2008
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In: Transportation Research. Part F: Traffic Psychology and Behaviour. - : Elsevier BV. - 1369-8478. ; 11:1, s. 37-51
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Journal article (peer-reviewed)abstract
- Driver comprehension and acceptance of the active accelerator pedal (AAP) after long-term use were evaluated in a large-scale Swedish trial held in 2000-2002. The system was installed in the cars of 281 test drivers who then used it for between six months and a year. The participants' responses, elicited by questionnaires in the end of the trial, showed a positive rating of the concept of the AAP, while the willingness to pay for it was lower than for other driver-assistance systems studied elsewhere. The typically skeptical driver was a young, male, company car driver with initially negative attitude and a faulty AAP. The typically enthusiastic driver was an older, female, private driver with initially positive attitude and a fault-free AAP. The drivers found that the system, if not satisfactory, was useful but added to the emotional pressure felt by the driver. However, they did think it had positive impacts on performance and safety. Still, the largest perceived effect was a decrease in the risk of being fined for speeding. The gap between the concept of the AAP and willingness to keep and pay for the system puts a clear focus on the importance to define acceptance and developing a tool to ensure reliable assessments of it.
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| 13. |
- af Wåhlberg, Anders, 1965-
(author)
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Changes in Driver Celeration Behavior over Time : do Drivers Learn from Collisions?
- 2012
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In: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 15:5, s. 471-479
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Journal article (peer-reviewed)abstract
- Although it is well known that drivers’ accident risk changes with experience, it has never been specified exactly how this comes about in terms of changes of behaviour, or what features of their experiences are important for this change. One possibility is that drivers learn from their collision involvement, and change their behaviour after such events, as some studies indicate. However, relative accident involvement tends to be very stable over time, which indicates the opposite. Repeated measurements of celeration (speed change) behaviour of bus drivers were compared between two groups; drivers without accidents within the measurement period (about 3 years), and drivers with at least one crash. For the crash group, there was a steady decline in their celeration values over time, but this was not related to their crashes. A similar reduction was also present for the non-crash sample. The results would seem to be in agreement with the theory of accident proneness; there exist stability in driver behaviour over time, despite accident involvement. However, this stability is relative within the sample, and not absolute. The reduction in celeration values for both groups over time would seem to indicate that drivers learn from their experiences in general, but not specifically from accidents. The present study seems to indicate that daily experience of driving situations is the strongest factor for changes in driving behaviour.
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| 14. |
- af Wåhlberg, Anders, 1965-
(author)
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Re-education of young driving offenders : Effects on recorded offences and self-reported collisions
- 2011
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In: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 14:4, s. 291-299
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Journal article (peer-reviewed)abstract
- New ways of educating offending drivers are being introduced, notably e-learning. This type of education has rarely been tested for its safety effects before. An e-learning course for offending young drivers was therefore evaluated as to its effects upon offence and self-reported collision rates. Significant reductions in number of offences and penalty points were found for an e-learning group, while this was not the case for drivers who had been fined only, or had taken a more traditional solely class-room based educational scheme. The e-learners also reported a larger reduction in collision involvement than a random control group, although a regression to the mean effect could not be ruled out. The results seem to indicate a positive effect of the e-learning course for young driving offenders. This conclusion, however, is to be interpreted in relation to the weak association between penalty points and collisions, and the low validity of self-reported collision involvement data. The present results lend further support to the use of e-learning driver improvement courses, although the most important type of data, recorded collisions, is still missing.
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| 15. |
- af Wåhlberg, Anders, 1965-, et al.
(author)
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The effect of social desirability on self reported and recorded road traffic accidents
- 2010
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In: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 13:2, s. 106-114
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Journal article (peer-reviewed)abstract
- The use of lie scales has a fairly long history in psychometrics, with the intention of identifying and correcting for socially desirable answers. This represents one type of common method variance (bias introduced when both predictors and predicted variables are gathered from the same source), which may lead to spurious associations in self-reports. Within traffic safety research, where self-report methods are used abundantly, it is uncommon to control for social desirability artifacts, or reporting associations between lie scales, crashes and driver behaviour scales. In the present study, it was shown that self-reports of traffic accidents were negatively associated with a lie scale for driving, while recorded ones were not, as could be expected if the scale was valid and a self-report bias existed. We conclude that whenever self-reported crashes are used as an outcome variable and predicted by other self-report measures, a lie scale should be included and used for correcting the associations. However, the only existing lie scale for traffic safety is not likely to catch all socially desirable responding, because traffic safety may not be desirable for all demographic groups. New lie scales should be developed specifically for driver behaviour questionnaires, to counter potential bias and artifactual results. Alternatively, the use of a single source of data should be discontinued.
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| 16. |
- Ahlström, Christer, et al.
(author)
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Bicyclists’ visual strategies when conducting self-paced vs. system-paced smartphone tasks in traffic
- 2015
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In: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 41, s. 204-216
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Journal article (peer-reviewed)abstract
- Visual distraction among cyclists interacting with their mobile phones is a growing concern. Yet, very little research has actually investigated how cyclists apply visual strategies and adapt task execution depending on the traffic situation. The aim of this study is to investigate visual behaviour of cyclists when conducting self-paced (initiated by the cyclist) vs. system-paced (initiated by somebody else) smartphone tasks in traffic. Twenty-two cyclists completed a track in real traffic while listening to music, receiving and making calls, receiving and sending text messages, and searching for information on the internet. The route and the types of tasks were controlled, but the cyclists could choose rather freely when and where along the route to carry out the tasks, thus providing semi-naturalistic data on compensatory behaviour. The results show that the baseline and music conditions were similar in terms of visual behaviour. When interacting with the phone, it was found that glances towards the phone mostly came at the expense of glances towards traffic irrelevant gaze targets and also led to shortened glance durations to traffic relevant gaze targets, while maintaining the number of glances. This indicates that visual “spare capacity” is used for the execution of the telephone tasks. The task type influenced the overall task duration and the overall glance intensity towards the phone, but not the mean nor maximum duration of individual glances. Task pacing was the factor that influenced visual behaviour the most, with longer mean and maximum glance durations for self-paced tasks. In conclusion, the cyclists used visual strategies to integrate the handling of mobile phones into their cycling behaviour. Glances directed towards the phone did not lead to traffic relevant gaze targets being missed. In system-paced scenarios, the cyclists checked the traffic more frequently and intensively than in self-paced tasks. This leads to the assumption that cyclists prepare for self-initiated tasks by for example choosing a suitable location. Future research should investigate whether these strategies also exists amongst drivers and other road user groups.
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| 17. |
- Alger, Susanne, 1967-, et al.
(author)
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Agreement of driving examiners' assessments : evaluating the reliability of the Swedish driving test
- 2013
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In: Transportation Research Part F. - : Elsevier. - 1369-8478 .- 1873-5517. ; 19, s. 22-30
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Journal article (peer-reviewed)abstract
- The purpose of this study was to examine the consistency of examiner assessments of test-takers' performance on the Swedish driving test. The study included 535 tests and was designed so that the ordinary examiner and a supervising examiner assessed the same test-taker. The assessment was done on a two-grade rating scale (pass/fail). Since the result can be affected by factors associated with the test-taker and the two examiners, questionnaires were developed and these were filled in by the test-takers and the examiners. Information about the administration of the test was collected via a specially designed form filled in by the supervising examiner. Using this form, the ordinary examiners' performance was rated on a number of aspects. The result from the study indicated that the agreement between the assessments was very good. For 93% of the tests the two examiners chose the same mark on the two-grade scale. In the cases where ratings differed, the analysis indicated only a few systematic differences among variables designed to provide possible explanations for differences in opinion. However, none of these was problematic with respect to consistency of assessment. Results indicated that most tests were carried out in a satisfactory manner.
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| 18. |
- Andersson, Jan, 1965-, et al.
(author)
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The complexity of changes in modal choice : A quasi-experimental study
- 2023
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In: Transportation Research Part F. - : Elsevier. - 1369-8478 .- 1873-5517. ; 96:July, s. 36-47
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Journal article (peer-reviewed)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.
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| 19. |
- Andersson, Jan, 1965-, et al.
(author)
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The proportions of severe and less severe bicycle crashes and how to avoid them
- 2024
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In: Transportation Research Part F. - : Elsevier. - 1369-8478 .- 1873-5517. ; 106:October, s. 169-178
-
Journal article (peer-reviewed)abstract
- BackgroundIn collaboration with a bicycle airbag helmet company, data were collected to help explain events where head protections are deployed. The head protection records activations continuously, and when a head protection is deployed, this information is sent to the company. The company invited affected cyclists to (i) participate in a web survey, and (ii) share their data with researchers. The first aim of the study was to investigate the proportions between different severities of crashes, i.e., how many crashes with serious injuries occur for every crash with minor injuries, while the second aim was to predict when bicycle crashes will occur.Method A total of 196 cyclists completed the web survey. Participants were 20–76 years old (mean age 46 years) and consisted of 125 women and 55 men. The cyclists were highly educated, and 73 percent had completed a university or college education. In addition, head protection data were collected from 355 other cyclists, of which 264 had their helmet deployed.ResultsOne of the 182 (included events) cyclists ended up in hospital care. The data collected indicated the proportions of cyclists who needed hospital care (1 = severe injuries), cyclists with injuries (15), slight injures (85) and cyclists who could continue as before (81 = no injuries). The head protection data confirmed the web survey findings, but also demonstrated that the head protection, on journeys that ended with head protection deployment, had a higher degree of activations before the event) compared to journeys where it was not deployed. Furthermore, on trips made after deployment, the head protection had lower levels of activations, which can be understood as the cyclists adapting their behavior by, for example, riding more carefully (but not slower).ConclusionThis study highlights the proportions of events leading to minor injuries versus hospitalization. Activation measures (head protection conditions) can predict when events will occur, and cyclists will adjust their behavior accordingly following events.
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| 20. |
- Aramrattana, Maytheewat, et al.
(author)
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A simulation framework for cooperative intelligent transport systems testing and evaluation
- 2019
-
In: Transportation Research Part F. - Kidlington : Elsevier. - 1369-8478 .- 1873-5517. ; 61:February, s. 268-280
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Journal article (peer-reviewed)abstract
- Connected and automated driving in the context of cooperative intelligent transport systems (C-ITS) is an emerging area in transport systems research. Interaction and cooperation between actors in transport systems are now enabled by the connectivity by means of vehicle-to-vehicle and vehicle-to-infrastructure (V2X) communication. To ensure the goals of C-ITS, which are safer and more efficient transport systems, testing and evaluation are required before deployment of C-ITS applications. Therefore, this paper presents a simulation framework-consisting of driving-, traffic-, and network-simulators-for testing and evaluation of C-ITS applications. Examples of cooperative adaptive cruise control (CACC) applications are presented, and are used as test cases for the simulation framework as well as to elaborate on potential use cases of it. Challenges from combining the simulators into one framework, and limitations are reported and discussed. Finally, the paper concludes with future development directions, and applications of the simulation framework in testing and evaluation of C-ITS.
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