| 1. |
- Fagerlind, Helen, 1975, et al.
(author)
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Development of an In-depth European Accident Causation Database and the Driving Reliability and Error Analysis Method, DREAM 3.0
- 2008
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In: 3rd International Conference ESAR (Expert Symposium on Accident Research). - Hannover, Tyskland.
-
Conference paper (other academic/artistic)abstract
- The SafetyNet project was formulated in part to address the need for safety oriented European road accident data. One of the main tasks included within the project was the development of a methodology for better understanding of accident causation together with the development of an associated database involving data obtained from on-scene or “nearly on-scene” accident investigations. Information from these investigations was complemented by data from follow-up interviews with crash participants to determine critical events and contributory factors to the accident occurrence. A method for classification of accident contributing factors, known as DREAM 3.0, was developed and tested in conjunction with the SafetyNet activities. Collection of data and case analysis for some 1 000 individual crashes have recently been completed and inserted into the database and therefore aggregation analyses of the data are now being undertaken. This paper describes the methodology development, an overview of the database and the initial aggregation analyses.
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| 2. |
- Ljung Aust, Mikael, 1973, et al.
(author)
-
Accident investigations for active safety at CHALMERS - new demands require new methodologies
- 2007
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In: Vehicle System Dynamics. - : Informa UK Limited. - 1744-5159 .- 0042-3114. ; 45:10, s. 881-894
-
Journal article (peer-reviewed)abstract
- In order to develop efficient active safety systems, knowledge about what causes traffic accidents is required. One way to gather such knowledge is through traffic accident investigations. For the needs of active safety, most current accident investigation methodologies do not provide a sufficiently detailed or theoretically anchored analysis. Therefore, new studies need to be carried out using new theoretical frameworks and analysis methods. At CHALMERS, a new methodology called driving reliability and error analysis method has been developed and tried out during recent years. The methodology, as described and exemplified, shows good promise of meeting the needs of active safety accident investigation projects. Results from studies using the methodology also imply consequences for how benefit estimation of new active safety systems should be carried out.
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| 3. |
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| 4. |
- Sandin, Jesper, 1975-, et al.
(author)
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Äldre förare av motorfordon i trafikolycka : Analys av data från Strada 2010–2019
- 2024
-
In: Sammanställning av postrar från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut.
-
Conference paper (other academic/artistic)abstract
- Ingen ökning av äldres olycksinblandning under tioårsperiodenÄldre förare fick allvarliga skador i framförallt korsningsolyckorÄldre förare var oftare inblandade i olyckor med oskyddade trafikanter som fick allvarliga skadorAvståndet mellan förarnas bostad och olycksplatsen minskade med ålder
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| 5. |
- Selander, Helena, 1975-, et al.
(author)
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Äldre bilförare : En litteraturgenomgång
- 2021
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Reports (other academic/artistic)abstract
- Rapporten är en kunskapssammanställning av befintliga forskningsresultat och litteratur om olyckor och riskfaktorer bland äldre bilförare (65+). Sammanställningen har varit en del i projektet ”Trafikolyckor och riskfaktorer bland äldre bilförare”. Det finns en stor mängd litteratur men många studier framhåller att äldre bilförare inte är en högriskgrupp ur trafiksäkerhetssynpunkt. Flertalet internationella studier visar på att äldre förare oftast kör säkert och har färre olyckor än yngre förare. Om man tar hänsyn till körsträckan är äldre dock överrepresenterade men det totala antalet olyckor är få. Vidare visar olycksstatistik ett generellt mönster där äldre förare är inblandade i fler olyckor med allvarliga personskador jämfört med medelålders förare. Flera studier hävdar att de här mönstren elimineras om man kompenserar för äldres fysiologiska skörhet och kortare körsträckor. Utöver en ökad skörhet med stigande ålder, visar även ett flertal studier att äldre förare har en större risk för trafikolyckor på grund av medicinska tillstånd, mediciner och funktionsnedsättningar som är vanliga i den äldre befolkningen. Dessutom framkommer specifika riskfaktorer, som exempelvis kognitiva, visuella och motoriska försämringar. I allmänhet är äldre förare säkra men dessa nedsättningar kan påverka körförmågan negativt. Det har dock varit svårt att definiera vid vilken gräns trafiksäkerhetsrisken är för hög. Sammanfattningsvis framkommer olika forskningsresultat angående om äldre bilförare verkligen har en högre risk än andra förare. En möjlig förklaring till de varierande resultaten i studierna som har publicerats är olika studiedesign och metodik, samt att det är relativt små populationer som har studerats. I Sverige har under de senaste åren den största ökningen av antalet omkomna varit bland personer över 65 år. Trafikolyckor medför betydande mänskliga och ekonomiska kostnader för den enskilde och samhället. Med bakgrund av att andelen äldre ökar i befolkningen, inklusive äldre körkortshavare, behöver deras säkerhet och skaderisker framöver undersökas närmare, speciellt med tanke på att nationella och europeiska studier är mycket sällsynta inom området.
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| 6. |
- Wallhagen, Susanne, 1961-, et al.
(author)
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Äldre förare av motorfordon i trafikolycka : analys av data från Strada 2010–2019
- 2022
-
Reports (other academic/artistic)abstract
- Trafikskador är både i Sverige och internationellt ett växande folkhälsoproblem med stora kostnader för samhället. Sammanställda data som idag finns över trafikolyckor relaterat till äldre förare är bristfällig och det saknas forskning inom området. Syftet med studien var därför att kartlägga olyckor (dödade, allvarligt skadade och lindrigt skadade) med äldre förare av motorfordon inblandade med avseende på olika olycksomständigheter. Ett urval av vägtrafikolyckor rapporterade av polis och akutsjukvård i Transportstyrelsens olycksdatabas Strada analyserades. Urvalet inkluderade alla som varit förare i en olycka med motorfordon under perioden 2010–2019 och vid olyckstillfället varit 65 år eller äldre. De inblandade förarna i vägtrafikolyckor var dödade, allvarligt skadade (ISS 9–) måttligt skadade (ISS 4–8), lindrigt skadade (ISS 1–3), oskadade eller hade en osäker skada. Främst studerades personbilsförare. I analyserna delades äldregruppen upp i en yngre grupp med 12 672 personbilsförare i åldrarna 65–74 år och en äldre grupp med 8 478 förare i åldrarna 75 år och äldre. Jämförelser gjordes med 55 855 yngre olycksinblandade personbilsförare, 40–55 år. Följande huvudfynd framkom i studien: • Det fanns ingen direkt olycksökning bland äldre personbilsförare under tioårsperioden. • Könsskillnaderna ökade med åldern. Kvinnorna som var 75 år och äldre utgjorde en lägre andel av de olycksinblandade, jämfört med andelen kvinnor i den yngre gruppen och jämförelsegruppen. • Olyckstyperna skiljde sig åt, där de äldsta i äldregruppen var mer inblandade i korsningsolyckor och olyckor med oskyddade trafikanter. • Det var något vanligare att de äldres olyckor skedde på vägar med lägre hastighetsgränser. • Det var mindre vanligt att de äldres olyckor skedde i mörker.
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| 7. |
- Wallhagen, Susanne, 1961-, et al.
(author)
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Äldre förare av motorfordon i trafikolycka : analys av data från Strada 2010–2019
- 2024
-
In: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 303-303
-
Conference paper (other academic/artistic)abstract
- Trafikskador är både i Sverige och internationellt ett växande folkhälsoproblem med stora kostnader för samhället. Sammanställda data som idag finns över trafikolyckor relaterat till äldre förare är bristfällig och det saknas forskning inom området. Syftet med studien var därför att kartlägga olyckor (dödade, allvarligt skadade och lindrigt skadade) med äldre förare av motorfordon inblandade med avseende på olika olycksomständigheter. Ett urval av vägtrafikolyckor rapporterade av polis och akutsjukvård i Transportstyrelsens olycksdatabas Strada analyserades. Urvalet inkluderade alla som varit förare i en olycka med motorfordon under perioden 2010–2019 och vid olyckstillfället varit 65 år eller äldre. De inblandade förarna i vägtrafikolyckor var dödade, allvarligt skadade (ISS 9–) måttligt skadade (ISS 4–8), lindrigt skadade (ISS 1–3), oskadade eller hade en osäker skada. Främst studerades personbilsförare. I analyserna delades äldregruppen upp i en yngre grupp med 12 672 personbilsförare i åldrarna 65–74 år och en äldre grupp med 8 478 förare i åldrarna 75 år och äldre. Jämförelser gjordes med 55 855 yngre olycksinblandade personbilsförare, 40–55 år. Följande huvudfynd framkom i studien: Det fanns ingen direkt olycksökning bland äldre personbilsförare under tioårsperioden. Könsskillnaderna ökade med åldern. Kvinnorna som var 75 år och äldre utgjorde en lägre andel av de olycksinblandade, jämfört med andelen kvinnor i den yngre gruppen och jämförelsegruppen.Olyckstyperna skiljde sig åt, där de äldsta i äldregruppen var mer inblandade i korsningsolyckor och olyckor med oskyddade trafikanter.Det var något vanligare att de äldres olyckor skedde på vägar med lägre hastighetsgränser.Det var mindre vanligt att de äldres olyckor skedde i mörker.
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| 8. |
- Andersson, Jan, et al.
(author)
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Trafiksäkerhetspåverkan vid omkörning av 30-metersfordon
- 2011
-
Reports (other academic/artistic)abstract
- Trafikverket överväger att tillåta längre och tyngre fordon på vägarna förutsatt att de inte påverkar trafiksäkerheten negativt. Syftet med studien var att undersöka säkerhetseffekten av fordonslängd, speciellt med avseende på olycksrisken vid omkörningar. Intervjuade förare av en 30-meters timmerbil hade inte upplevt de farhågor som förare av normallånga lastbilar uttryckt i samband med trånga rondeller och korsningar, men de nämner betydelsen av stödjande åkeri, arbetsmiljö och fordonsutrustning. En simulatorstudie studerade bilförares omkörningar av ett 30- och ett 18,75-metersfordon på en 2+1-väg i situationen då två körfält går ihop till ett. Tidluckan till ett återstående körfält var i genomsnitt 0,2 s (sign.) kortare efter omkörningar av 30-metersfordonet i situationer då bakänden var i samma relativa position som för 18,75-metersfordonet vid början av omkörningen. En fältstudie analyserade videoinspelade omkörningar av en 30- och en 24-meters timmerbil på en 2+1-väg och en tvåfältig väg. Ingen signifikant skillnad i tidluckor kunde påvisas mellan omkörningar av de två fordonen för någon av vägtyperna. Det senare resultatet ska dock tolkas med försiktighet på grund av ojämnt distribuerad data som insamlats under specifika förhållanden. Slutsatserna är att det finns en liten tendens till negativ säkerhetseffekt vid omkörningar av längre fordon, och att fler fältstudier är nödvändiga.
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| 9. |
- Bianchi Piccinini, Giulio, 1982, et al.
(author)
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How Do Drivers Respond to Silent Automation Failures? Driving Simulator Study and Comparison of Computational Driver Braking Models
- 2020
-
In: Human Factors. - Chalmers University of Technology, Gothenburg, Sweden.; Volvo Group Trucks Technology, Gothenburg, Sweden.; Virginia Tech Transportation Institute, Blacksburg, USA.; University of Leeds, UK.; VTI, Gothenburg, Sweden. : SAGE Publications. - 1547-8181 .- 0018-7208. ; 62:7, s. 1212-1229
-
Journal article (peer-reviewed)abstract
- Objective: This paper aims to describe and test novel computational driver models, predicting drivers’ brake reaction times (BRTs) to different levels of lead vehicle braking, during driving with cruise control (CC) and during silent failures of adaptive cruise control (ACC). Background: Validated computational models predicting BRTs to silent failures of automation are lacking but are important for assessing the safety benefits of automated driving. Method: Two alternative models of driver response to silent ACC failures are proposed: a looming prediction model, assuming that drivers embody a generative model of ACC, and a lower gain model, assuming that drivers’ arousal decreases due to monitoring of the automated system. Predictions of BRTs issued by the models were tested using a driving simulator study. Results: The driving simulator study confirmed the predictions of the models: (a) BRTs were significantly shorter with an increase in kinematic criticality, both during driving with CC and during driving with ACC; (b) BRTs were significantly delayed when driving with ACC compared with driving with CC. However, the predicted BRTs were longer than the ones observed, entailing a fitting of the models to the data from the study. Conclusion: Both the looming prediction model and the lower gain model predict well the BRTs for the ACC driving condition. However, the looming prediction model has the advantage of being able to predict average BRTs using the exact same parameters as the model fitted to the CC driving data. Application: Knowledge resulting from this research can be helpful for assessing the safety benefits of automated driving.
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| 10. |
- Dozza, Marco, et al.
(author)
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MICA2 : Modelling Interaction between Cyclists and Automobiles 2
- 2023
-
Reports (other academic/artistic)abstract
- FFI-projektet MICA (180401-191231) visade hur förarmodeller kan hjälpa automatiska bromssystem att bli smartare och aktiveras mer effektivt utan att kompromissa med föraracceptans. MICA2 har haft ett brett fokus på hela omkörningen då både aktiva och passiva säkerhetssystem har utvecklats och testats i projektet:Försäkringsdata och olycksdatabaser har analyserats för att identifiera olycksscenarion och olycksmekanismer för alla faser i omkörningen.Flera beteendemodeller har utvecklats för att hantera hela omkörningsmanövern vid simuleringar. Modellerna tar hänsyn till både förarens objektiva säkerhet, cyklistens perspektiv på situationen och den upplevda säkerheten för alla involverade trafikanter.Modellerna har använts för att utveckla och analysera aktivering av automatisk bromsning och -styrning i kritiska omkörningssituationer.Externa krockkuddar och expanderbara metallstrukturer för personbilar som kan lindra skadeutfallet hos cyklister har utvecklats och testats.En effektanalys av systemen har genomförts som visade att expanderbar metallstruktur på en bil kan minska risken för moderata/svåra huvudskador från 69% till 9%. Dessutom bedömdes att ett AEB-system med MICA2-modeller skulle kunna undvika 20% av omkörningsolyckorna helt.Nya metoder för datainsamling har utvecklats - som ger helt nya möjligheter att generera och verifiera beteendemodeller och att jämföra olika testmiljöer. Data har samlats in i både cykel- och körsimulatorer. Vidare har virtual realtity använts i ett experiment på provbana utan att äventyra deltagarnas säkerhet. Dessutom, genom att väva ihop indata från olika kamerasystem, har unika naturalistiska data samlats in med motorfordonsförare som kör om cyklister i verklig trafik.Resultaten från MICA2 gör det möjligt att utveckla nya säkerhetssystem, ger ny input till utveckling av experimentella procedurer i Euro NCAP och främjar säker interaktion mellan automatiserade fordon och cyklister.
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| 11. |
- Eriksson, Alexander, et al.
(author)
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Drivers’ recovery performance in a critical run-off-road scenario : A driving simulator study
- 2018
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In: Proceedings of the 6th Humanist Conference, The Hague, Netherlands, 13-14 June 2018. - : HUMANIST Virtual Centre of Exellence.
-
Conference paper (other academic/artistic)abstract
- Single vehicle accidents are commonly caused by fatigue and distraction and resulting in severe casualties and high economic costs. In order to evaluate driver recovery from run-off-road accidents, comprising of 80% of fatal crashes on rural roads, a simulator study in an advanced full-motion driving simulator was carried out. Drivers were given a secondary task to perform at six positions down the road (to simulate distraction), and an artificial yaw deviation was added to the vehicle to induce a run-off-road accident whilst the driver was distracted. The results show that the severity of the recovery manoeuvre was larger than similar events caused by the failure of automated lane keeping systems, leading to lane departures. Furthermore, significant learning effects was found, providing recommendations for further studies into run-off-road experiments.
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| 12. |
- Hjort, Mattias, 1972-, et al.
(author)
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Utredning av regler för vinterdäck till tunga fordon : Ett regeringsuppdrag
- 2023
-
Reports (other academic/artistic)abstract
- VTI har tillsammans med Transportstyrelsen fått i uppdrag av regeringen att analysera dagens krav på vinterdäck för tunga fordon och utreda behovet av förändrade krav på vinterdäck eller däckutrustning för att minska framkomlighets- och säkerhetsproblem i vägtrafiken när det råder vinterväglag. Om behov finns ska Transportstyrelsen föreslå regeländringar. 2018 togs beslut fram på skärpta krav på vinterdäck till tunga fordon. Kraven blev aktiva 1 juni 2019. I uppdraget från regeringen ingick att följa upp hur de skärpta kraven efterlevs och bedöma vilken effekt som regeländringarna har fått på framkomlighet och trafiksäkerhet. Vi har i denna utredning genomfört fokusgrupper och intervjuer, samlat in statistik och genomfört olycksriskanalyser, samt utfört ett par fältstudier av däckens kondition för lastbilar och bussar i trafik. Vi har gått igenom befintligt regelverk i detalj och jämfört dem med regelverken i Norge och Finland, där man har liknande vinterförhållanden som i Sverige. Baserat på dessa analyser ser vi inga skäl till förändringar av befintligt regelverk för vinterdäck till tunga fordon. Den statistiska analysen kunde inte påvisa någon förbättring av halkrelaterade problem efter skärpningen av vinterdäcksreglerna 2019, varken när det gäller framkomlighet eller trafiksäkerhet.
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| 13. |
- Huang, Yu-Hsing, et al.
(author)
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Accident Models for Modern Road Traffic : Changing Times Creates New Demands
- 2004
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In: Proceedings of the International Conference on Systems, Man and Cybernetics.
-
Conference paper (other academic/artistic)abstract
- The purpose of this study is to develop accident models that can be applied to modern road traffic. Several criteria are proposed that a model suitable for the conditions of modern road traffic should fulfil. Four commonly applied general accident models are reviewed, and found to be inadequate in relation to the criteria. Also, the consequences of an underlying structural problem in all four model types, which is the result of regarding the human as a system component, are discussed. To remedy the discovered problems, it is argued that traffic safety should make use of the developments that have been made in the field of industrial safety. Several suggestions are proposed for how a new model could be developed, based on experiences from industrial safety.
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| 14. |
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| 15. |
- Jernberg, Christian, 1985-, et al.
(author)
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The effect of latency, speed and task on remote operation of vehicles
- 2024
-
In: Transportation Research Interdisciplinary Perspectives. - : Elsevier. - 2590-1982. ; 26, s. 101152-101152
-
Journal article (peer-reviewed)abstract
- Method: Thirty-one participants drove in simulated rural (high-speed) and urban (low-speed) scenarios. Five hazards were created for each scenario and the participants drove each scenario three times with different latencies (baseline, +100 ms, and +200 ms). The latency condition was masked for the participants. The hazards were designed with the intention of creating challenging traffic situations. For example, in hazard one (H1) a car parked next to the road activates their turn indicators and then cuts into the participant's lane close in front of the ego vehicle, forcing the participant to either brake or veer. Latency, type of hazard, and scenarios (high- and low-speed) were all within participants’ variables.Objective simulator data collected included variables such as reaction time, post-encroachment time, speed variation, distance to hazard, collisions, etc. Subjective data was gathered through questionnaires between each of the balanced latency conditions to assess trust, perceived control, realism of scenarios, and workload etc. After the completed drive, participants were asked to rate in which order they believed they had been subjected to the different latencies. The participants were divided into two groups, experienced drivers and experienced gamers.Conclusion: There seems to be a certain level of adaptivity among the participants, although they were not told that the latency varied between scenarios, and they could also not guess in which order they drove with the different conditions. In some situations, they drove with larger safety margins, especially experienced gamers in the high-speed scenario. Moreover, the subjective ratings show that participants felt less in control of the vehicle at higher latencies without being able to pinpoint what it was that affected their driving.
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| 16. |
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| 17. |
- Kharrazi, Sogol, 1980-, et al.
(author)
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A review of more than a decade of research and field tests on longer vehicle combinations in Sweden that supported road approval
- 2024
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In: Technology Convergence 2023. - : International Forum for Heavy Vehicle Transport & Technology; The International Society for Weigh-In-Motion.
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Conference paper (other academic/artistic)abstract
- For more than a decade, Longer Vehicle Combinations (LVCs) have been tested in Sweden on roads and test tracks and studied in simulations. Based on the outcomes of this research, the government in Sweden has decided to open part of the road network for LVCs with a length up to 34.5 m. Necessary regulatory framework should be in place before this change can be applied. Thus, the LVCs are not expected on the roads before winter 2023-2024. This article reviews outcomes of the extensive research which has been performed on High Capacity Transport (HCT) to support introduction of LVCs in Sweden. Summary of studies on various aspects of HCT, such as regulation, safety, maneuverability, electrification, and emissions, are presented.
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| 18. |
- Kharrazi, Sogol, 1980-, et al.
(author)
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Performance based standards for high capacity transports in Sweden : FIFFI project 2013-03881: Report 1: Review of existing regulations and literature
- 2015
-
Reports (other academic/artistic)abstract
- Project Performance Based Standards (PBS) for High Capacity Transports (HCT) in Sweden started at the end of 2013 to investigate applicability of PBS in Sweden. The purpose of the project is to propose a performance based regulation of HCT vehicles and their access to the road network; under a PBS approach to regulation, standards would specify the performance required from vehicle, rather than mandating how this level of performance should be achieved by putting limits on the vehicle length or weight. In this project, all the three domains of safety, infrastructure and environment will be addressed, but the focus is on safety for which extensive testing, simulations and analysis are planned. This report gathers the outcome of work packages 1 and 2 of the project, which is a review of the existing regulation in Sweden, PBS approaches in other countries and relevant literature and regulations.
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| 19. |
- Kharrazi, Sogol, 1980, et al.
(author)
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Performance based standards for high capacity transports in Sweden -- Report 1 Review of existing regulations and literature
- 2015
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Reports (other academic/artistic)abstract
- Project “Performance Based Standards for High Capacity Transports in Sweden” started at the end of 2013 to investigate applicability of PBS in Sweden. The purpose of the project is to propose a performance based regulation of HCT vehicles and their access to the road network; under a PBS approach to regulation, standards would specify the performance required from vehicle, rather than mandating how this level of performance should be achieved by putting limits on the vehicle length or weight. In this project, all the three domains of safety, infrastructure and environment will be addressed, but the focus is on safety for which extensive testing, simulations and analysis are planned.This report gathers the outcome of work packages 1 and 2 of the project, which is a review of theexisting regulation in Sweden, PBS approaches in other countries and relevant literature andregulations.
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| 20. |
- Kircher, Albert, 1975, et al.
(author)
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Vehicle control and drowsiness
- 2002
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Reports (other academic/artistic)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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| 21. |
- Kircher, Katja, 1973-, et al.
(author)
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Omkörning av cyklister med duo-trailer-lastbilar (HCT)
- 2024
-
In: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 244-244
-
Conference paper (other academic/artistic)abstract
- Att köra med så-kallad High Capacity Transport (HCT), dvs. lastbil med två påhängsvagnar där hela ekipaget blir 32 m långt, skulle reducera bränsleförbrukningen vid godstransport på väg. Samtidigt är det känt att cyklisters trygghet och säkerhet påverkas bland annat av det omkörande fordonets avstånd i sidled, hastighet och storlek. Dessa faktorer påverkar också den aerodynamiska effekten på cyklisten. Frågeställningen här var om det är möjligt att köra om cyklister med HCT-fordon på ett säkert sätt och vad det i så fall innebär, som förutsättning för att kunna röra sig på samma vägnät. På en inomhustestbana (DryZone, AstaZero) kördes 23 cyklister med vana att cykla på landsväg om av en HCT-lastbil och en lastbil med en påhängsvagn (16 m lång). Omkörningshastigheten var 50 eller 80 km/h och det laterala avståndet till cyklisten var 1 m, 1.5 m eller 2 m. En referensomkörning med 50 km/h på 3.5 m avstånd gjordes också. Forskningspersonerna cyklade på en fri rulle och var säkrade med sele. Cykelns förflyttning i sidled på rullen under omkörning, lufttrycket från lastbilen i längs- och sidled och cyklistens skattning av trygghet samt en verbal beskrivning av faktorerna som påverkade skattningen loggades. Avslutningsvis fyllde deltagarna i en enkät som handlade om omkörning, upplevd säkerhet och komfort i en vidare bemärkelse. Deltagarna angav även på skalenliga bilder hur de ansåg att en betryggande omkörning skulle behöva gå till, beroende på situation och den omkörande fordonstypen.De subjektiva skattningarna visar att avståndet i sidled har störst inverkan på cyklisternas upplevelse av trygghet, följd av omkörningshastigheten. Fordonets längd var av mindre betydelse för skattningen, även om många cyklister kommenterade att den längre lastbilen genererade en starkare sugeffekt än den kortare lastbilen. Samtliga omkörningar i testet skattades som mindre tryggt än referensomkörningen. Lufttrycksmätningarna visade att det laterala avståndet hade störst inverkan på amplituden av den laterala tryckvågen. Den högre hastigheten ökade amplituden ytterligare. Referensomkörningen orsakade inga signifikanta utslag på lufttrycksmätningen. Effekten på cykelns sidoförflyttning återstår att analyseras.
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| 22. |
- Nilsson, Peter, et al.
(author)
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High speed control of long combination heavy commercial vehicles within safe corridors
- 2016
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Reports (other academic/artistic)abstract
- The main scope of the project was to initiate a technical framework for studying manual and automated high-speed driving of long vehicle combinations (LVCs) in a driving simulator environment.The project included implementation and evaluation of vehicle models representing a rigid truck solo (reference vehicle) and an A-double LVC in VTI driving simulator IV (Sim IV). The A-double combination consisted of a 6x4 tractor unit followed by a three-axle semi-trailer, two-axle converter dolly and a second three-axle semi-trailer unit. The total vehicle length of the A-double was 32 metres and the total weight was set to 80 tonnes. The implementation of the vehicle models was evaluated by drivers from Volvo product development. The evaluation was carried out during normal driving conditions, with speeds ranging from 0 to 90 km/h.Besides the implementation and evaluation of vehicle models, the project also included a driving simulator study in which manual and automated driving of the A-double have been studied. The participants in the study were 12 professional truck drivers from a haulage contractor and 8 drivers from Volvo product development. The driving scenario consisted of a relatively curvy and hilly single-lane Swedish county road (Road 180), without additional road users and safety critical events. Two automated driving strategies for steering, propulsion and braking were formulated, whereof one of the steering strategies included results from an optimal control based receding horizon approach. The drivers’ manual lane keeping and speed profiles were recorded for post-analysis. In addition, the drivers’ subjective acceptance of automated driving trajectories was also collected.
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| 23. |
- Nilsson, Peter, 1976, et al.
(author)
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On actions of long combination vehicle drivers prior to lane changes in dense highway traffic : A driving simulator study
- 2018
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In: Transportation Research Part F. - : Elsevier. - 1369-8478 .- 1873-5517. ; 55, s. 25-37
-
Journal article (peer-reviewed)abstract
- In this paper we address drivers’ actions prior to mandatory lane changes of long combination vehicles in dense highway traffic. The studied driver actions were: turn indicator activation, speed reduction and lateral intrusion. We categorised and compared the drivers’ actions with respect to the surrounding traffic cooperation and the level of urgency. Urgency here was based on the remaining distance to a targeted exit ramp. The results show that when the subject vehicle is close to the exit ramp, drivers used speed reduction significantly more than when the vehicle is further away. No significant difference was found for the use of lateral intrusion considering the distance to the exit ramp. As regards traffic cooperation, significant differences were found for both speed reduction and lateral intrusion. The drivers’ speed reduction and lateral intrusion were significantly greater when the surrounding traffic cooperation was low.
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| 24. |
- Sandin, Jesper, 1975-, et al.
(author)
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A Lane-Change Gap Acceptance Scenario Developed for Heavy Vehicle Active Safety Assessment : A Driving Simulator Study
- 2015
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In: Proceedings of the 3rd International Symposium on Future Active Safety Technology Towards zero traffic accidents, 2015. ; , s. 537-543
-
Conference paper (peer-reviewed)abstract
- The aims of this study were to develop a lane-change scenario for driving simulators in order to analyse the characteristics of lane-change manoeuvres performed with heavy vehicles. The scenario was set up based on information from lane-change accidents and on-road lane-change observations. The gap acceptance scenario consisted of two consecutive lane changes were the intention was to study truck drivers’ accepted gap between two vehicles in the adjacent right lane, at the initiation of each lane change. An experiment was conducted with 18 truck drivers in a full-motion driving simulator with implemented high fidelity models of an 80tonnes and 32m long vehicle combination and a 40tonnes and 22m tractor semi-trailer. The results showed no statistically significant difference in the accepted gaps to the lead and lag vehicles in the target lane. For both heavy vehicles, the overall average lead gap and lag gap was estimated to 0.85s and 0.83s respectively, at the average velocity of 17.3m/s. The difference in lane-change duration for the two vehicles was statistically significant and estimated to an average of 8.7s for the tractor semi-trailer, and 10.5s for the A-double. The conclusion from the present study is that the drivers performed the lane changes equally well with the tractor semi-trailer and the long vehicle combination. There were no major differences between the manoeuvres other than the duration times, which can be justified by the difference in vehicle length. Future studies are able to use this scenario as a non-critical reference to more critical events in the development and assessment of active safety functionality and automated driving systems.
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| 25. |
- Sandin, Jesper, 1975-, et al.
(author)
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A lane-change scenario developed for assessment of active safety and ADAS in heavy vehicles : evaluated in a driving simulator study
- 2017
-
Reports (other academic/artistic)abstract
- The aim of this project was to develop a lane-change scenario for driving simulators to analyse the characteristics of lane-change manoeuvres performed with heavy vehicles.The definition of the lane-change scenario was based on a literature review, and an investigation of lane-change accidents in Sweden.A lane-change manoeuvre is in the literature typically described by accepted gap at the initiation of the manoeuvre as well as duration of the manoeuvre and speed during the manoeuvre. The literature review showed that there is a lack of real-world data regarding lane-change manoeuvres with heavy vehicles. The data that exist are collected mainly in the US and for discretionary lane changes, and a distinction between sizes of heavy vehicles is rarely made. Regarding accidents involving heavy vehicles on European level, there is a general lack of useful and reliable accident data. The most comprehensive data are available from the US and show that lane-change accidents account for a large share of accidents involving heavy vehicles.The investigation of lane-change accidents was made in the Swedish Traffic Accident Data Acquisition (STRADA), on 10 500 police-reported accidents with heavy vehicles involved during the years 2003 to 2013. In STRADA, lane-change accidents are categorized together with overtaking accidents. Therefore, it is not possible to identify lane-change accidents and their share of heavyvehicle accidents directly from STRADA. Instead, lane-change accidents were identified by reading the accident narratives for overtaking accident and rear-end accidents (in total 5 612 accidents). Rearend accidents were included because the manner of collision may resemble lane-change collisions.
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| 26. |
- Sandin, Jesper, 1975-
(author)
-
Aggregating Case Studies of Vehicle Crashes by Means of Causation Charts : An Evaluation and Revision of the Driving Reliability and Error Analysis Method
- 2008
-
Doctoral thesis (other academic/artistic)abstract
- There is a need for increased knowledge about causes to motor-vehicle crashes and their prevention. Multidisciplinary in-depth case studies can provide detailed causation data that is otherwise unattainable. Such data might allow the formulation of hypotheses of causes and causal relationships for further study. By converting the data into causation charts that are aggregated, common causation patterns would give greater weight to such hypotheses. However the charts must first be compiled by means of a systematic analysis method, which requires three parts; a model, a classification scheme and a classification method.Four general accident models were evaluated and found inadequate to form the basis for a causation analysis method. This was primarily because the models in practice treat road-users, vehicles and traffic environment as separate components, but also due to the focus on events immediately prior to the crash and either static, sequential, or absent modelling of interaction.Two studies were carried out to evaluate whether case files could be aggregated by means of charts that had been compiled with the Driving Reliability and Error Analysis Method (DREAM). In DREAM, contributory factors (genotypes) are systematically analysed, classified and linked in a single chart for each driver that illustrate the causes of a critical event (phenotype). In the first study, case files from 38 single-vehicle crashes were examined to distinguish crashes with similar circumstances. Four types of loss of vehicle control were identified, for which the associated DREAM charts were aggregated. The results revealed common patterns within the types, as well as different patterns between them. The second study focused on 26 intersection crashes. Based on the most common violations at intersections, six risk situations were defined, and the DREAM charts associated with each risk situation were aggregated. A common pattern in each of two risk situations indicated that drivers with and without the right of way had not seen the other vehicle due to distractions and/or sight obstructions. A frequently occurring pattern for the drivers with the right of way was that they had not expected another vehicle to cross their path. The absence of clear patterns in three risk situations was a result of a low number of charts and rather unique circumstances in these cases. Parts of the aggregated charts contained an unexpectedly large variation, identified as a consequence of inconsistently compiled charts.Prior the final study assessing intercoder agreement, DREAM was revised into a new version based on the experience from the latter aggregation study. A total of seven investigators from four European countries compiled seven DREAM charts for each driver involved in four types of accidents. The results indicated that the intercoder agreement for genotypes ranged from 74% to 94% with an average of 83%, while it for phenotypes ranged from 57% to 100% with an average of 78%. This acceptable level of agreement is expected to rise with enhanced training. The present thesis thus shows that DREAM is a highly promising method for the compilation of causation charts. Future studies are expected to benefit from aggregating DREAM charts when formulating hypotheses of general causes and causal relationships as a subject for further research, as well as to identify alternative countermeasure strategies.
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| 27. |
- Sandin, Jesper, 1975
(author)
-
An analysis of common patterns in aggregated causation charts from intersection crashes
- 2009
-
In: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575. ; 41:3, s. 624-632
-
Journal article (peer-reviewed)abstract
- intersection crashes are a major traffic problem. Greater knowledge of causation is required in order to prevent them with the implementation of active safety measures. Causation charts were aggregated to establish whether common patterns of interlinked factors could be found. The data used comprised causation charts for 52 drivers involved in 26 in-depth investigated urban intersection crashes. The charts were compiled by means of the Driving Reliability and Error Analysis Method (DREAM) version 2.1, in which contributing factors are systematically analysed, classified and linked in a causation chart. The charts were aggregated for six defined risk situations, four for drivers without the right of way and two for those with the right of way. in two risk situations, one for drivers with and one for the drivers without the right of way, common patterns showed that the drivers had not seen the other vehicle due to distractions and/or sight obstructions. A frequently occurring pattern for the drivers with the right of way was that they had not expected another vehicle to cross their path. The absence of clear patterns in three risk situations for the drivers without the right of way was due to the low number of charts and rather unique circumstances. Parts of the aggregated charts showed an unwarranted variation, identified as a consequence of inconsistent charts. The present study shows that the rather unique approach of aggregating causation charts has potential, provided that the charts are consistent. (C) 2009 Elsevier Ltd. All rights reserved.
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| 28. |
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| 29. |
- Sandin, Jesper, 1975, et al.
(author)
-
Crash investigations for active safety: Meeting new demands on investigation methodology
- 2004
-
In: 1: st International Conference on ESAR - Expert Symposium of Accident Research, Hannover, Germany, September.
-
Conference paper (other academic/artistic)abstract
- Active safety systems are aimed at accident prevention, hence the knowledge required for their development is different from that required for passive safety systems aimed at injury prevention. Particularly, knowledge about accident causation is required. When looking at existing accident causation data, it is argued it fails to explain in sufficient detail how and why the accidents occur. Therefore, there is a need for detailed micro-level descriptions of accident causation mechanisms, and also of methodologies suitable for creating such descriptions. One study addressing these needs is the Swedish project FICA (Factors Influencing the Causation of Accidents and incidents), where an accident investigation methodology suitable for active safety is developed, and in-depth accident investigations following this methodology are carried out on-scene in the area of Gothenburg by a multidisciplinary team. A preliminary aggregated analysis of different cases show that the methodology developed is adequate for pointing out common contributing factors and devising principal countermeasures.
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| 30. |
- Sandin, Jesper, 1975
(author)
-
DREAM: A Method for Understanding the Causation of Single-Vehicle Crashes
- 2006
-
Licentiate thesis (other academic/artistic)abstract
- When conducting in-depth causation studies, it is essential that the analysis method can both define and classify contributing factors and be able to analyse how these factors may interact to produce a critical event. These issues are highly influenced by the underlying theory, e.g. the accident model. Consequently, the first study in this thesis surveyed the characteristics of four general accident models, i.e. sequential models, epidemiological models, energy transfer models and systemic models. Based on the accident model survey, this thesis investigated the characteristics of accident models applied in five previous accident causation studies, three statistical studies and two case studies. In the investigation, it was found that the statistical studies had not defined an accident model. This together with other methodological deficiencies resulted in the misleading conclusion that human factors are responsible for up to 70-95% of traffic accidents. The two case studies defined detailed accident models, forming the base for their causation analysis methods. However, because of an implemented driver model based on the information-processing concept, the accident models received features resembling the disadvantages of sequential accident models. As a result, every accident was analysed and explained always using the same structure of causation. Further, the results in the form of case reports provided limited possibilities to compare similar accidents and see common causation characteristics, e.g. through comparing contributory factors and their interactions.In the second study of this thesis, a promising method for analysing causation, Driving Reliability and Error Analysis Method (DREAM), was presented and demonstrated in an in-depth investigation of 38 single-vehicle crashes (SVCs). DREAM is based on the principles of systemic accident models. Consequently, DREAM consists of a factor and a linkage structure that is flexible enough to analyse the various types of causation factors that together may contribute to an accident. The result of a DREAM analysis is illustrated as an accident pattern for each accident case. The individual SVCs were compared to distinguish cases with similar crash circumstances. As a result, causation patterns were combined into four scenarios that demonstrate the most frequently occurring factors and links. The four scenarios described in greater detail the factors that contribute to accidents characterised by road departure, slipperiness, excessive speed or excessive driver manoeuvres. Because of the flexible structure, the sequence of a DREAM analysis may first appear abstract and therefore difficult to immediately understand. Consequently, there is a risk that analysts with different competence may produce diversified results. However, this risk will likely be reduced with more distinct factor definitions, education and experience.
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| 31. |
- Sandin, Jesper, 1975-, et al.
(author)
-
Evaluation of a Run-off-Road Scenario for Driving Simulators used for the Assessment of Automatic Steering-Wheel Interventions
- 2015
-
In: Proceedings of the 3rd International Symposium on Future Active Safety Technology Towards zero traffic accidents, 2015. ; , s. 545-550
-
Conference paper (peer-reviewed)abstract
- The setup of a run-off-road scenario was based on the current knowledge about critical run-off-road situations and accidents. The scenario was initiated by a visual secondary task. During the task, an added clockwise yaw deviation, intended to create the run-off-road scenario, was presented visually but not by the vehicle dynamics or the lateral acceleration of the simulator’s motion system. Results from two experiments show that the drivers frequently neutralised the yaw deviation because of their lack of full attention to the secondary task, the occasionally rough yaw deviation, or a combination of both. Because of the frequently neutralised yaw deviations, the number of steering-wheel interventions from an implemented system, intended to steer back into the lane in run-off-road situations, became limited in number. The system generated in total 14 steering-wheel interventions, ranging from torque levels of 0.3 to 3.7Nm. During ten of the interventions, the driver counteracted the torque with one hand. Nevertheless, the drivers that had experienced the interventions would like to have a system that could steer back to the lane when approaching the road edge, and accept that it takes control of the steering wheel. Further research on shared steering control is required so that driver responses to interventions does not neutralise the intended safety benefit of the system.
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| 32. |
- Sandin, Jesper, 1975, et al.
(author)
-
Large Moving Base Simulators and Automation Design for Heavy Vehicles - Case Study for HCT
- 2016
-
In: International Symposium on Heavy Vehicle Transport Technology (HVTT14).
-
Conference paper (other academic/artistic)abstract
- This work aimed at analysing the potential for the application of large driving simulators on the study of future automated driving functionality. The case study was centred on applications for heavy vehicles, focusing on lane-change manoeuvres and automated driving. A simulation environment was created which hosted a model of a real world road, motion emulation with high fidelity truck dynamics, controllable surrounding traffic and a driver assistance system including autonomous driving. Two types of heavy vehicles were selected for this study, an 80ton and 32m long A-Double combination vehicle and a 40ton and 20m tractor semi-trailer. The final experimental set-up was driven by a group of professional truck drivers. It was concluded that today’s resources in terms of hardware, software and even knowledge base satisfy the requirements for testing such automated systems in a holistic way. Driving simulators are capable of providing much valued feedback as well as insight at early stages of function design which can effectively speed up, focus and streamline further development.
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| 33. |
- Sandin, Jesper, 1975, et al.
(author)
-
Understanding the causation of single-vehicle crashes: a methodology for in-depth on-scene multidisciplinary case studies
- 2007
-
In: International Journal of Vehicle Safety. - 1479-3105 .- 1479-3113. ; 2:3, s. 316-333
-
Journal article (peer-reviewed)abstract
- Knowledge of the interaction between and consequences of causation factors is essential when designing active safety measures. There is frequently a lack of adequate details in the area of causation, especially pertaining to Single-Vehicle Crashes (SVCs). This study describes the in-depth and on-scene investigations of 38 SVCs that took place in Gothenburg, Sweden. The causation factors involved were analysed using the Driving Reliability and Error Analysis Method (DREAM). The 38 SVCs were grouped into four scenarios. In the first scenario, vehicles drifted out of lane due to driver fatigue, sleepiness or distraction. In the second, an undetectable reduction in road friction caused experienced drivers to lose control in curves. Loss of control in curves was also a factor in scenario three, partly due to high speed. In this scenario, drivers overestimated their driving skills or had limited experience of the vehicle or the curve. In the final scenario, alarmed drivers lost control as a result of excessive steering-wheel manoeuvres. This study demonstrates a methodology that can be used to explain how a combination of factors may increase the risk of SVCs.
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| 34. |
- WALLÉN WARNER, HENRIETTE, 1972, et al.
(author)
-
Dream 3.0. Documentation of references supporting the links in the classification scheme
- 2008
-
Reports (other academic/artistic)abstract
- Both the Driving Reliability and Error Analysis Method (DREAM; Ljung, 2002) and theSafetyNet Accident Causation System (SNACS; Ljung, 2006) have been successfully used astools for accident analysis in Sweden as well as in other European countries. While the drivervehicle/traffic environment-organisation triad are used as frames of reference and theContextual Control Model (COCOM; Hollnagel, 1998) is used to organise human cognition,the links in the classification schemes have not been established by referring to literature. Theaim of this literature review is therefore to investigate the empirical support for the links inthe classification scheme of DREAM 3.0 (an updated version of DREAM/SNACS).
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| 35. |
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| 36. |
- WALLÉN WARNER, HENRIETTE, 1972, et al.
(author)
-
The intercoder agreement when using the Driving Reliability and Error Analysis Method in road traffic accident investigations
- 2010
-
In: Safety Science. - : Elsevier BV. - 0925-7535 .- 1879-1042. ; 48:5, s. 527-536
-
Journal article (peer-reviewed)abstract
- Many different classification schemes have been used in the analysis of road traffic accidents but the agreement between coders using the same classification scheme is rarely tested and/or reported. As a high intercoder agreement is a prerequisite for a study's validity, this is a serious shortcoming. The aim of the present study was, therefore, to test the intercoder agreement of the Driving Reliability and Error Analysis Method (DREAM) version 3.0 by letting seven coders from different European countries analyse and classify the causes of the same four accident scenarios. The results showed that the intercoder agreement for genotypes (contributing factors) ranges from 74% to 94% with an average of 83%, while for phenotypes (observable effects) it ranges from 57% to 100% with an average of 78%. The results also showed that weaknesses in classification schemes, methods, training of coders as well as in presentation of accident information can be identified by testing the intercoder agreement. (C) 2010 Elsevier Ltd. All rights reserved.
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