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Kircher, K. & Ahlström, C. (2024). A comparison of glance coding approaches for driver attention assessment. Transportation Research Part F: Traffic Psychology and Behaviour, 100, 243-253
Open this publication in new window or tab >>A comparison of glance coding approaches for driver attention assessment
2024 (English)In: Transportation Research Part F: Traffic Psychology and Behaviour, ISSN 1369-8478, E-ISSN 1873-5517, Vol. 100, p. 243-253Article in journal (Refereed) Published
Abstract [en]

Eye tracking is a common tool to assess drivers’ attentional state, either in real-time with the goal to prevent incidents, or offline, to understand underlying processes. While seemingly objective, eye tracking data can be coded and interpreted in different ways, which can have substantial effects on the results. The objective of this paper is to highlight and discuss the possibilities and limitations of three different approaches to code glance data: the direction-based encoding, the target-based approach, and the purpose-based approach. The direction-based coding scheme describes glances relative to the direction of travel. The target-based approach classifies the glance targets into different categories. The purpose-based approach needs additional layers of information to deduce the reason for the glance. This information encompasses road layout, traffic rules, and the presence and relevance of other traffic.

Data from a field study with 23 participants driving an instrumented vehicle on an urban route was used to illustrate differences between the three methods. The results showed that the coding approach clearly affected the interpretation of the measured glance data. A purely target-based approach is limited by its inability to account for spare visual capacity and that also the absence of a target constitutes valuable information, and a purely direction-based approach does not account for the need to scan areas located off forward. The purpose-based approach requires contextual information that can be cumbersome to integrate. Regardless of the approach used, additional layers of contextual information increase understanding and interpretability, potentially at the cost of increased complexity. The three approaches are suitable for different contexts and their feasibility also depends on the availability of additional data. A key message is that context awareness improves the accuracy of driver attention monitoring and inattention identification.

Place, publisher, year, edition, pages
Elsevier, 2024
National Category
Applied Psychology Human Computer Interaction
Identifiers
urn:nbn:se:vti:diva-20105 (URN)10.1016/j.trf.2023.12.003 (DOI)001135980400001 ()2-s2.0-85179128743 (Scopus ID)
Funder
Vinnova, 2017-05526
Available from: 2024-01-04 Created: 2024-01-04 Last updated: 2024-02-01Bibliographically approved
Kircher, K., Ahlström, C., Odéen, M., Hamidi, Z. & Nordin, L. (2023). Aktivt resande och uppmärksamhet: vilka krav ställer trafikmiljön på barns och ungdomars uppmärksamhet?. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Aktivt resande och uppmärksamhet: vilka krav ställer trafikmiljön på barns och ungdomars uppmärksamhet?
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2023 (Swedish)Report (Other academic)
Alternative title[en]
Active travel and attention : which demands does the traffic environment place on children’s and youngster’s attention?
Abstract [sv]

Projektet undersöker hur barns ålder påverkar deras förmåga till uppmärksamhet i trafiken när de cyklar och går till skolan. Datamaterialet utgörs av svaren på en enkät om skolvägar (432 elever från 45 olika skolor), en semi-kontrollerad fältstudie där barnens beteende på väg till skolan loggades (20 fotgängare, 42 cyklister), samt en observationsstudie i olika korsningar (609 fotgängare, 277 cyklister). Resultaten tyder på att trafikmiljön snarare än barns ålder påverkar hur väl kraven på uppmärksamhet uppfylls i en situation. Detta går hand i hand med tidigare forskning som visar att det till stor del beror på trafikmiljön om det är säkert att vistas där, och att det inte finns någon allmän åldersgräns för när det är lämpligt att röra sig i trafiken. Snarare spelar utformningen av miljön en betydande roll för hur väl kraven på uppmärksamhet kan hanteras. Det visade sig också ha betydelse om eleverna rörde sig i grupp eller själva och hur grupperna var sammansatta både i termer av ålder och färdsätt. 

Resultaten från datainsamlingarna visar att utformning av infrastruktur, vart man är på väg, trafikslag och trafikregler påverkar vilka områden som är viktiga att titta åt för att säkerställa att vägen är fri. Genom att lägga till sådan information i ett geografiskt informationssystem (GIS) kan man systematiskt undersöka hur förändringar i infrastrukturen påverkar kraven på uppmärksamheten för olika trafikslag och i olika situationer. En första implementation har gjorts i projektet för att visa på potentialen för ett GIS-verktyg som tar hänsyn till krav på uppmärksamhet. Ett sådant verktyg skulle underlätta för planerare och andra som gestaltar trafikmiljöer så att dessa kan utformas på ett sätt som är tryggt och trafiksäkert för barn och unga. 

Sammantaget visar resultaten att trafikmiljön snarare än ålder och kognitiv mognad sätter ramarna för vem som kan eller bör vistas i transportsystemet. Utgångspunkten att barn inte är kapabla att vistas i trafiken behöver nyanseras.

Abstract [en]

The project examines how children’s age affects their ability to be attentive in traffic when cycling or walking to school. The data material consists of answers to a questionnaire about school routes (432 students from 45 different schools), a semi-controlled field study where the children's behaviour on the way to school was logged (20 pedestrians, 42 cyclists), as well as an observational study in various intersections (609 pedestrians, 277 cyclists). The results indicate that the traffic environment, rather than the age of the child, influences how well the attention requirements in a situation are met. This goes hand in hand with previous research which shows that it largely depends on the traffic environment whether it is safe to be there, and that there is no general age limit for when it is appropriate to participate in traffic. Rather, the design of the environment plays a significant role in how well the attentional demands can be managed. It also turned out to be important whether the students moved in a group or by themselves and how the groups were composed both in terms of age and mode of travel. 

The results from the data collections show that infrastructure design, the direction of travel, road user types and traffic rules influence which areas are important to scan visually to ensure that the road is clear. By adding such information to a geographic information system (GIS), one can systematically investigate how changes in the infrastructure affect attention requirements for different road user types and in different situations. A first implementation has been done in the project to demonstrate the potential of a GIS tool that takes attention requirements into account. Such a tool would make it easier for planners and others who shape traffic environments so that these can be designed in a way that is and feels safe for children and young people. 

Overall, the results show that the traffic environment, rather than age and cognitive maturity, sets the framework for who can or should participate in the transport system. The notion that children are not capable of participating in traffic needs to be nuanced.

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2023
Series
VTI resultat ; 2023:9
National Category
Applied Psychology
Identifiers
urn:nbn:se:vti:diva-20021 (URN)
Available from: 2023-11-30 Created: 2023-11-30 Last updated: 2023-11-30Bibliographically approved
Ahlström, C., Zemblys, R., Finér, S. & Kircher, K. (2023). Alcohol impairs driver attention and prevents compensatory strategies. Accident Analysis and Prevention, 184, Article ID 107010.
Open this publication in new window or tab >>Alcohol impairs driver attention and prevents compensatory strategies
2023 (English)In: Accident Analysis and Prevention, ISSN 0001-4575, E-ISSN 1879-2057, Vol. 184, article id 107010Article in journal (Refereed) Published
Abstract [en]

While the negative effects of alcohol on driving performance are undisputed, it is unclear how driver attention, eye movements and visual information sampling are affected by alcohol consumption. A simulator study with 35 participants was conducted to investigate whether and how a driver's level of attention is related to self-paced non-driving related task (NDRT)-engagement and tactical aspects of undesirable driver behaviour under increasing levels of breath alcohol concentration (BrAC) up to 1.0 ‰. Increasing BrAC levels lead to more frequent speeding, short time headways and weaving, and higher NDRT engagement. Instantaneous distraction events become more frequent, with more and longer glances to the NDRT, and a general decline in visual attention to the forward roadway. With alcohol, the compensatory behaviour that is typically seen when drivers engage in NDRTs did not appear. These findings support the theory that alcohol reduces the ability to shift attention between multiple tasks. To conclude, the independent reduction in safety margins in combination with impaired attention and an increased willingness to engage in NDRTs is likely the reason behind increased crash risk when driving under the influence of alcohol. © 2023

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Alcohol, Attention, Distraction, Driving, Eye tracking, Impairment, Automobile drivers, Behavioral research, Eye movements, Alcohol concentrations, Compensatory strategy, Driver attention, Driving performance, Eye-tracking, Visual information
National Category
Applied Psychology
Identifiers
urn:nbn:se:vti:diva-19567 (URN)10.1016/j.aap.2023.107010 (DOI)000945900600001 ()2-s2.0-85148333510 (Scopus ID)
Funder
Vinnova, 2019-05834
Available from: 2023-03-01 Created: 2023-03-01 Last updated: 2023-05-23Bibliographically approved
Andersson, J., Patten, C., Wallén Warner, H., Andersérs, C., Ahlström, C., Ceci, R. & Jakobsson, L. (2023). Bicycling during alcohol intoxication. Traffic Safety Research, 4, Article ID 000028.
Open this publication in new window or tab >>Bicycling during alcohol intoxication
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2023 (English)In: Traffic Safety Research, ISSN 2004-3082, Vol. 4, article id 000028Article in journal (Refereed) Published
Abstract [en]

The number of bicycling fatalities was 19 450 between 2010 and 2018 in Europe. The number of bicyclists killed when intoxicated by alcohol is harder to establish given the lack of reliable data. In Sweden, drunk bicycling is socially acceptable and legal (unless reckless). This experiment aimed to investigate how alcohol intoxication affect bicycling stability performance, executive functions, and self-rated ability. The experiment was completed on a wide treadmill that allowed control of several influencing factors such as speed and physical effort. Intoxicated and sober participants bicycled on the treadmill for five 10 minute sessions. Alcohol as administered incrementally to reach a target breath alcohol concentration level of 0.8‰. Stability decreased with intoxication; especially roll rate measurements were identified as being adequate indicators of bicycling instability. Executive function was negatively affected, and ability ratings decreased due to intoxication. The intoxicated participants were aware of their reduced ability to bicycle in a safe manner on a group level but not on an individual level. However, this insight does not affect their intention to bicycle intoxicated.

Place, publisher, year, edition, pages
Lund University Faculty of Engineering, 2023
Keywords
alcohol intoxication, bicycling performance, cognition, stability
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:vti:diva-19839 (URN)10.55329/prpa1909 (DOI)2-s2.0-85166901850 (Scopus ID)
Available from: 2023-08-16 Created: 2023-08-16 Last updated: 2024-02-21Bibliographically approved
Kircher, K. & Ahlström, C. (2023). Children and youngster's gaze behaviour when cycling in familiar environments. Journal of Cycling and Micromobility Research, 1, Article ID 100006.
Open this publication in new window or tab >>Children and youngster's gaze behaviour when cycling in familiar environments
2023 (English)In: Journal of Cycling and Micromobility Research, ISSN 2950-1059, Vol. 1, article id 100006Article in journal (Refereed) Published
Abstract [en]

Active travel is beneficial for individuals and society in many ways. As transportation habits are formed at a young age, active school transport should be promoted. However, young children are often portrayed as not being able to cope with the demands traffic imposes on them. Most studies tend to confirm the notion that older children perform better than younger children, however, they are usually conducted in controlled environments that are unfamiliar to the participants. Here, 28 participants in two age groups (6–12 and 13–18 years) cycled their usual way to school to guarantee familiarity with the environment. They wore eye trackers, and the surroundings were filmed by a camera on the handlebars and by another camera mounted on the bicycle of an experimenter, who followed the participant. For each trip, all attentional target areas were identified based on infrastructure layout, traffic rules and turning direction. It was coded whether the children monitored these areas. Additionally, glance targets and glance purpose were coded. More than 80 % of all target areas were monitored. Regardless of age, a higher number of simultaneous target areas increased the likelihood that some relevant target areas were missed. The glance distribution across different types of target areas did not vary between the age groups. An increase in the number of simultaneous target areas led to a decrease in spare visual capacity and an increase in glances dedicated to checking for traffic. Overall, children in both age groups were generally attentive in their familiar environment. Difficulties were associated with a higher number of simultaneous target areas. A more controlled setup is needed to identify potentially modifying factors, and a comparison with adults is needed to for a fair valuation of the children’s performance.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Cycling, Children, Youngsters, Attention, Age, Environmental factors, Field study, Eye tracking, Semi-controlled, Familiarity
National Category
Transport Systems and Logistics Applied Psychology
Identifiers
urn:nbn:se:vti:diva-20168 (URN)10.1016/j.jcmr.2023.100006 (DOI)
Funder
Länsförsäkringar AB, P6/20
Available from: 2024-01-29 Created: 2024-01-29 Last updated: 2024-01-29Bibliographically approved
Picher, C., Bachler, M., Ahlström, C., Mayer, C. C. & Hametner, B. (2023). Fit for Duty Assessment of Driver Fatigue based on Statistical Modelling of Cardiovascular Parameters. SNE Simulation Notes Europe, 33(4), 157-166
Open this publication in new window or tab >>Fit for Duty Assessment of Driver Fatigue based on Statistical Modelling of Cardiovascular Parameters
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2023 (English)In: SNE Simulation Notes Europe, E-ISSN 2306-0271, Vol. 33, no 4, p. 157-166Article in journal (Refereed) Published
Abstract [en]

Driver fatigue is a risk factor for road crashes. Fit for duty technologies could play a pivotal role in countering these crashes. Heart rate variability (HRV) and the pulse wave shape are influenced by the autonomic nervous system and are therefore affected by fatigue. This work focusses on modelling their relationship with fatigue and is based on data recorded in a simulated driving study. Six different multivariate linear regression models, using either stepwise variable selection or principal component analysis, are presented in this study. To account for differences in physiology, individual participant baselines for HRV and pulse wave parameters are introduced. Stepwise regression using any kind of baseline yields the most promising results. The most promising predictors are the ratio LFHF between low and high frequency components of HRV and heart rate. Finally, a stepwise regression model with a baseline, which has an adjusted R2 statistic of 0.17, is proposed for further use. Nevertheless, further research with an extended dataset is necessary, incorporating a more diverse participant group and a higher number of recordings from severely sleepy drivers. 

Place, publisher, year, edition, pages
ARGESIM, 2023
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:vti:diva-20169 (URN)10.11128/sne.33.tn.10663 (DOI)
Projects
PANACEA
Funder
EU, Horizon Europe, 953426
Available from: 2024-01-29 Created: 2024-01-29 Last updated: 2024-01-29Bibliographically approved
Kircher, K., Finér, S., Zemblys, R. & Ahlström, C. (2023). Fit2Drive. Fordonsstrategisk Forskning och Innovation. FFI
Open this publication in new window or tab >>Fit2Drive
2023 (English)Report (Other academic)
Abstract [sv]

Syftet med denna studie var att bedöma hur alkoholpåverkan interagerar med förarens uppmärksamhet och hur det påverkar lämpligheten att köra bil. Trettiofem deltagare körde i en simulator och på en testbana medan de var nyktra och under påverkan av alkohol med ökande alkoholhalt i utandningsluften (BrAC). De insamlade data inkluderade videoupptagningar av förarens huvud- och ögonrörelser, inspelningar av insidan av kupén och förarens överkropp, hjärtaktivitet och körbeteende.

Studien visade att uppmärksamhetsfördelning inte var tillräcklig för detektion av alkoholpåverkan, medan psykofysiologiska mått som fixeringstid och -hastighet samt saccad-amplituder var lämpliga kandidater för universell alkoholpåverkansdetektion. Blinkdynamiken visade också tydliga effekter av alkoholpåverkan. Placeringen av kameran bör beaktas för framtida algoritm-utveckling.

Studien visade att tre olika variabelgrupper - uppmärksamhet, utförande av extrauppgifter (NDRT) och körkvalitet – påverkades negativt efter alkoholkonsumtion. Deltagarna tenderade att titta bort från vägen längre, medan blickarna till speglarna minskade. Antalet utförda NDRT ökade med högre BrAC-nivåer, och medelblicklängden till NDRT-skärmen nästan fördubblades vid 1,0 ‰ jämfört med nykterhet. Dessutom försämrades körkvaliteten: Deltagarna körde snabbare, vinglade mer, och deras säkerhetsmarginaler gentemot andra minskade.

Kombinationen av minskad uppmärksamhet, ökat NDRT-engagemang och kompromissad körkvalitet skapar således en "farlig blandning". En diskriminant-analys genomfördes för att bedöma de kombinerade variablernas indikativa värde för BrAC-klassificering. Sammanfattningsvis fann studien att alkohol försämrar uppmärksamheten, leder till minskade säkerhetsmarginaler vid körning och mindre restriktivt engagemang i icke-körrelaterade uppgifter.

Abstract [en]

The goal of the project was to assess fitness to drive, and specifically how alcohol intoxication interacts with driver attention and drowsiness. A test track and simulator study involved 35 participants driving in a simulator and on a test track while sober and under the influence of alcohol with increasing levels of breath alcohol content. The data collected included video recordings of the driver's head and eye movements, recordings of the inside of the cabin and the driver's upper body, heart activity measurements and driving behaviour.

The study aimed to evaluate how various behavioural and psychophysiological measures froma driver monitoring system are affected by intoxication levels and if a single camera system can still robustly measure them. It was also found that attention proportion measures were not suitable for intoxication detection due to data loss, while psychophysiological measures like fixation duration and rate and saccade amplitudes were good candidates for universal intoxication detection. Blink dynamics also showed a clear effect of intoxication. It was also found that camera placement should be taken into account for future algorithm development.

The measured variables were categorized into three groups: attention, non-driving related task (NDRT) engagement, and driving quality. Most of these variables were not highly correlated. The study found that overall, all three variable groups were negatively affected after alcohol consumption. Participants tended to glance away from the forward roadway for longer periods of time, while glances to the mirrors decreased. The number of NDRTs executed increased with higher BrAC levels, and the mean glance duration to the NDRT screen almost doubled in the 1.0 ‰ condition compared to sober. Furthermore, the quality of driving deteriorated, with participants driving faster and weaving more, and their safety margins towards others were reduced.

The study suggests that the combination of decreased attention, increased NDRT engagement, and compromised driving quality creates a "dangerous cocktail" of ingredients. A discriminant analysis was conducted to assess the combined variables' indicative value for BrAC classification. The study found that alcohol impairs attention, leads to decreased safety margins in driving and less restrictive engagement in NDRT.

Place, publisher, year, edition, pages
Fordonsstrategisk Forskning och Innovation. FFI, 2023. p. 22
National Category
Applied Psychology
Identifiers
urn:nbn:se:vti:diva-19903 (URN)
Projects
Trafiksäkerhet och automatiserade fordon
Funder
Vinnova, 2019-05834
Available from: 2023-09-18 Created: 2023-09-18 Last updated: 2023-10-03Bibliographically approved
Ahlström, C., Wörle, J., Ljung Aust, M. & Frederik, D. (2023). Road Vehicle Automation and Its Effects on Fatigue, Sleep, Rest, and Recuperation (1ed.). In: Christina M. Rudin-Brown and Ashleigh J. Filtness (Ed.), The Handbook of Fatigue Management in Transportation: Waking Up to the Challenge. Boca Raton: CRC Press
Open this publication in new window or tab >>Road Vehicle Automation and Its Effects on Fatigue, Sleep, Rest, and Recuperation
2023 (English)In: The Handbook of Fatigue Management in Transportation: Waking Up to the Challenge / [ed] Christina M. Rudin-Brown and Ashleigh J. Filtness, Boca Raton: CRC Press, 2023, 1Chapter in book (Other academic)
Abstract [en]

Assisted and automated driving brings new challenges and opportunities when it comes to driver fatigue. With lower levels of vehicle automation, driver monotony and boredom in combination with demanding attentive monitoring leads to higher levels of fatigue, especially during the night when the sleep pressure is high. With higher levels of vehicle automation, when the driver is not required to continuously monitor the roadway and the automation system, task-related fatigue can be counteracted by engaging in non-driving-related activities. Finally, with the highest levels of vehicle automation, it may even become possible for drivers to sleep while on the move. Aside from making it possible for private car drivers to take strategic naps during a drive, this also opens up the possibility for more flexible, risk management-based, hour of service regulations for professional drivers. This chapter summarises the current state of the art on how assisted and piloted driving affects driver fatigue and how automation may facilitate recovery and recuperation from fatigue while on the move. It also covers how automated functions will impact driver monitoring systems and how new ways of counteracting driver fatigue may arise when automation is available.

Place, publisher, year, edition, pages
Boca Raton: CRC Press, 2023 Edition: 1
National Category
Vehicle Engineering Applied Psychology
Identifiers
urn:nbn:se:vti:diva-19832 (URN)10.1201/9781003213154 (DOI)2-s2.0-85167685751 (Scopus ID)9781003213154 (ISBN)
Available from: 2023-08-15 Created: 2023-08-15 Last updated: 2023-08-29Bibliographically approved
Kircher, K. & Ahlström, C. (2022). Driver attention monitoring and visual sampling from relevant and irrelevant targets. In: DDI 2022 Gothenburg: Abstract book. Paper presented at The 8th international conference on driver distraction and inattention. Lindholmen Conference Centre & online October 19–20, 2022 (pp. 4-7). Göteborg: Safer
Open this publication in new window or tab >>Driver attention monitoring and visual sampling from relevant and irrelevant targets
2022 (English)In: DDI 2022 Gothenburg: Abstract book, Göteborg: Safer , 2022, p. 4-7Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Driver attention is often assessed via glance behaviour, typically by measuring glances away from the forward roadway or by directly measuring glances to non-driving related targets. This approach can be used to detect distracting events, but it does not check whether all situationally relevant targets are sampled. Here, we evaluate the usefulness of the MiRA-theory as basis for attention assessment. A field study was conducted with 23 participants driving an instrumented vehicle on an urban route. The participants wore a head-mounted eye tracker. Data reduction included the identification of target areas that needed to be sampled, whether they were sampled or not, and whether relevant or irrelevant other traffic was present. Additionally, a gaze-by-gaze analysis identified gaze direction, purpose, and target. As predicted, drivers sampled all required target areas that necessitated a glance away from forward. Target areas roughly in the forward direction, like zebra crossings, were probably sampled with peripheral vision, but this could not be reliably confirmed with the equipment used. The glance direction distribution was found to correspond well to the a- priori-defined requirements. A higher number of parallel requirements induced a larger share of glances with the purpose to check for traffic. Relevant traffic was monitored more than irrelevant traffic. A higher number of parallel requirements was associated with reduced spare visual capacity. Nominal glance target identification was less linked to the requirements. We therefore recommend that “traditional” glance-based attention assessment should be complemented with a purpose-based glance assessment protocol coupled with situation dependent pre-defined requirements.

Place, publisher, year, edition, pages
Göteborg: Safer, 2022
National Category
Applied Psychology
Identifiers
urn:nbn:se:vti:diva-19338 (URN)
Conference
The 8th international conference on driver distraction and inattention. Lindholmen Conference Centre & online October 19–20, 2022
Available from: 2023-01-11 Created: 2023-01-11 Last updated: 2023-01-11Bibliographically approved
Vecchiato, G., Ahlström, C. & Chuang, L. L. (2022). Editorial: Cognitive Mechanisms for Safe Road Traffic Systems. Frontiers in Neuroergonomics, 3
Open this publication in new window or tab >>Editorial: Cognitive Mechanisms for Safe Road Traffic Systems
2022 (English)In: Frontiers in Neuroergonomics, E-ISSN 2673-6195, Vol. 3Article in journal, Editorial material (Refereed) Published
Place, publisher, year, edition, pages
Frontiers Media S.A., 2022
National Category
Applied Psychology
Identifiers
urn:nbn:se:vti:diva-19489 (URN)10.3389/fnrgo.2022.897659 (DOI)
Available from: 2023-01-24 Created: 2023-01-24 Last updated: 2023-01-24Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4134-0303

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