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| 2. |
- Chiari, Lorenzo, et al.
(författare)
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Audio-biofeedback for balance improvement: an accelerometry-based system.
- 2005
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Ingår i: IEEE Transactions on Biomedical Engineering. - 0018-9294 .- 1558-2531. ; 52:12, s. 2108-11
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Tidskriftsartikel (refereegranskat)abstract
- This paper introduces a prototype audio-biofeedback system for balance improvement through the sonification using trunk kinematic information. In tests of this system, normal healthy subjects performed several trials in which they stood quietly in three sensory conditions while wearing an accelerometric sensory unit and headphones. The audio-biofeedback system converted in real-time the two-dimensional horizontal trunk accelerations into a stereo sound by modulating its frequency, level, and left/right balance. Preliminary results showed that subjects improved balance using this audio-biofeedback system and that this improvement was greater the more that balance was challenged by absent or unreliable sensory cues. In addition, high correlations were found between the center of pressure displacement and trunk acceleration, suggesting accelerometers may be useful for quantifying standing balance.
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| 3. |
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| 4. |
- Dozza, Marco, 1978
(författare)
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BikeModel: modeller för cyklistbeteende - Slutrapport
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta projekt använde naturalistisk data från projekt BikeSAFER och e-BikeSAFE för att utreda hur cyklistbeteende och cykeldynamik ändras när cyklister byter från traditionella cyklar till el-cyklar.Våra analyser visar att:•el-cyklar ökar individers cykelmedelhastighet med 7-31%•När cyklister byter from traditionella cyklar till el-cyklar upplever de:ohögre cykelshastighet (cirka 3,6 km/t)o34% oftare hastigheter över 30 km/t (som är den svenska hastighetsbegränsningen för cyklar).olägre longitudinella och laterala accelerationer (mer konstanta hastigheter och mindre laterala rörelser)ohögre vertikala accelerationer (mer vibrationer)olägre longitudinell acceleration för alla hastigheterohögre lateral acceleration vid låga hastigheter (0-5 km/h) och lägre för alla andra hastighetsintervallofler kritiska händelser vid högre hastighet och som kräver hårdare inbromsningarDessa resultat indikerar att:•El-cyklar exponerar cyklister till högre (och oftare olagliga) hastigheter än traditionella cyklar.•Generellt är el-cyklar bekvämare att cykla på än traditionella cyklar inte bara för att de kräver mindre energi men också för att de medför mindre acceleration.•Det är svårare att förutsäga andra väganvändare när man cyklar med el-cykel (vilket kan beror på att andra väganvändare har svårt att förutsäga el-cyklisterna).•Cyklister behöver vara redo att bromsa oftare och hårdare när de kör en el-cykel jämfört med traditionella cyklar.•El-cyklar kan vara mindre stabila än traditionella cyklar vid låga hastigheter (0-5 km/t).•El-cyklister måste köra om andra cyklister mycket ofta.•El-cyklister tenderar att närma sig korsningar med en konstant hastighet på 25 km/h, oberoende av om de planerar att stanna eller köra igenom korsningen. Generellt är el-cyklister snabbare, har svårare att planera inbromsningar, och kör oftare om andra cyklister, än cyklister som cyklar på traditionella cyklar. Konsekvensen blir att många situationer som redan utmanar cyklister (t.ex. hinder på cykelbanor, dålig synlighet, vägarbete, etc.) kommer vara ännu svårare och potentiellt kritiska för el-cyklister.Slutrapporten inkluderar analysdetaljer, refererar till några vetenskapliga publikationer från projektet, och presenterar rekommendationer för vägdesign, konstruktionsarbete, vägunderhåll, samhällsutbildning, samt el-cykelsdesign.
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| 5. |
- Dozza, Marco, 1978
(författare)
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BikeSAFER: Final Report
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- BikeSAFER has been an important milestone for Chalmers and SAFER offering a fertile ground fornew national and international collaborations and providing a stable foundation for new projects.The naturalistic cycling data from BikeSAFER is presently unique in the world and strengthen theSwedish leading role on collection and analysis of naturalistic data worldwide. Analyses fromBikeSAFER, which are currently under review by several international scientific journals, have alreadystarted to drive future projects and collaborations in Sweden, Europe, US, China, and Australiawhere connections have been already established with SAFER partners, GDV/University of Munich,University of Michigan Transportation Research Institute, Tongji University, and University of SouthWales, respectively. For instance, one of the bicycles from BikeSAFER is currently in Ann Arbor (MI),USA as part of Safety Pilot (18M$; largest collection of wireless vehicle data in the world) collectingnaturalistic cycling data including beaconing from 3000 motorized vehicles, 10 motorcycles, andseveral road side units in the largest cooperative environment worldwide.One of the major strengths of naturalistic studies is the possibility to reuse the collected data. In thisrespect, BikeSAFER created a snapshot of the cycling situation in Göteborg which can serve newanalyses and as a baseline for future studies. A few projects orbited around the naturalistic cyclingdata from BikeSAFER. The BikeCOM project in the Master for Automotive Engineering at Chalmersmade use of BikeSAFER data to develop a smartphone application for cycling safety1. Anotherproject, BikeSING2, has been using BikeSAFER data in combination with data from STRADA, insurance(IF), and exposure (Göteborgsstad) to cast light on single‐bicycle accidents. The new project e‐BikeSAFE, partly sponsored by Trafikverket, will use BikeSAFER data to compare traditional bicycle tonew electrical bicycles in order to determine the impact of electrical bicycles on traffic safety;whereas the BikeSING2 project will now extend the work of BikeSING to new datasets.BikeSAFER was accepted as a SAFER associated project. As such, BikeSAFER progresses werepresented regularly at the meetings of the Traffic Safety Analysis competence area. These occasionsfavored a more close interaction with other actors interested on cycling safety such as:Göteborgsstad, VTI, IF, Volvo Cars, Autoliv, Viktoria Institutet, and Trafikverket. For instance, extrafunding from Trafikverket enabled a larger collection of data in BikeSAFER compared to the originalplan. The SAFER network was used to advertise an International Workshop on Naturalistic CyclingAnalysis, which is largely based on the results from BikeSAFER and will be hold at SAFER onSeptember 3rd 2013 as a satellite event of the Driver Distraction and Inattention Conference.This report presents the main scientific results from BikeSAFER and shows how naturalistic cyclingdata can explain accident causation, cyclist behavior including interaction with other road users, andbicycle dynamics. The results from this report are important for policy makers and city planners asthey offer new insights into cyclist behavior in relation to traffic safety, infrastructure design, andadherence to traffic rules. In addition, the results from this project can guide the development ofintelligent countermeasures as demonstrated by the BikeCOM project. Finally, the results presentedin this report have been or will be presented to several national and international conferencesincluding Transportforum and the Nationell Konference i Transportforskning.
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| 6. |
- Dozza, Marco, 1978
(författare)
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Combining Data Sets for Analysis of Cycling Safety: How Detailed Exposure Data Can Help Explain Crash Data
- 2015
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Ingår i: Proceedings of the 4th International Cycling Safety Conference, Hannover, 15-16 Sept 2015.
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Konferensbidrag (refereegranskat)abstract
- Crash databases are commonly queried to infer crash causation, prioritize countermeasures toprevent crashes, and evaluate safety systems. However, crash databases fail to capture roaduser behavior before the crash and are not sufficient to estimate crash risk. In Sweden, as inmany other countries, crash databases are particularly sterile when it comes to bicycle crashes.In fact, not only are bicycle crashes underreported in police reports, they are also poorly documentedin the hospital report. Nevertheless, police and hospital reports an unreplaceablesource of information that clearly highlights the surprising prevalence of single‐bicycle crashesand hints to some cyclist behavior, such as alcohol consumption, that may increase crash risk.In this study, we use exposure data from 11 road site stations measuring cyclist flow inGothenburg to help explain crash data from police and hospital reports and estimate risk. Forinstance, our results show that crash risk is greatest in weekends at nights, and that this risk islarger for single‐bicycle crashes compared to crashes between a cyclist and another motorist.This result suggests that the population of night‐cycling riders in weekends is particularlyprone to specific crash types, which may be influenced by specific contributing factors (such asalcohol), and may require specific countermeasures. More in general, our results demonstratethat exposure data can help select, filter, aggregate, highlight, and normalize crash data to obtaina sharper view of the cycling safety problem for a more fine‐tuned intervention.
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| 7. |
- Dozza, Marco, 1978
(författare)
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Crash Risk: How Cycling Flow Can Help Explain Crash Data
- 2017
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Ingår i: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575. ; 105:SI, s. 21-29
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Tidskriftsartikel (refereegranskat)abstract
- Crash databases are commonly queried to infer crash causation, prioritize countermeasures to prevent crashes, and evaluate safety systems. However, crash databases, which may be compiled from police and hospital records, alone cannot provide estimates of crash risk. Moreover, they fail to capture road user behavior before the crash. In Sweden, as in many other countries, crash databases are particularly sterile when it comes to bicycle crashes. In fact, not only are bicycle crashes underreported in police reports, they are also poorly documented in hospital reports. Nevertheless, these reports are irreplaceable sources of information, clearly highlighting the surprising prevalence of single-bicycle crashes and hinting at some cyclist behaviors, such as alcohol consumption, that may increase crash risk.In this study, we used exposure data from 11 roadside stations measuring cyclist flow in Gothenburg to help explain crash data and estimate risk. For instance, our results show that crash risk is greatest at night on weekends, and that this risk is larger for single-bicycle crashes than for crashes between a cyclist and another motorist. This result suggests that the population of night-cyclists on weekend nights is particularly prone to specific crash types, which may be influenced by specific contributing factors (such as alcohol), and may require specific countermeasures. Most importantly, our results demonstrate that detailed exposure data can help select, filter, aggregate, highlight, and normalize crash data to obtain a sharper view of the cycling safety problem, to achieve a more fine-tuned intervention.
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| 8. |
- Dozza, Marco, 1978, et al.
(författare)
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How do drivers overtake cyclists?
- 2016
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Ingår i: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575. ; 88, s. 29-36
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Tidskriftsartikel (refereegranskat)abstract
- In Europe, the number of road crashes is steadily decreasing every year. However, the incidence of bicycle crashes is not declining as fast as that of car crashes. In Sweden, cyclists are the most frequently injured road users. Collisions between bicycles and motorized vehicles are of particular concern because the high speed and large mass of motorized vehicles creates a high risk of serious injury to cyclists. In Sweden’s urban areas, bicycle lanes keep bicycles separated from motorized vehicles, but on rural roads bicycle lanes are often absent, requiring drivers to interact with cyclists— usually by overtaking them. During this maneuver, the driver regulates speed and lateral position, negotiating with potential oncoming traffic to stay within their comfort zone while approaching and passing the cyclist.In this study an instrumented bicycle recorded 145 overtaking maneuvers performed by car and truck drivers on public rural roads in Sweden. The bicycle was equipped with a LIDAR and two cameras to assess how drivers approached and circumvented the bicycle. The collected data allowed us to identify four overtaking phases and quantify the corresponding driver comfort zones. The presence of an oncoming vehicle was the factor that most influenced the maneuver, whereas neither vehicle speed, lane width, shoulder width nor posted speed limit significantly affected the driver comfort zone or the overtaking dynamics.
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| 9. |
- Dozza, Marco, 1978
(författare)
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NoRisk2Bike - Slutrapport
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta projekt har inspirerats av resultat som visar att risken för cykelolyckor ökar under natten, trots att de flesta olyckor sker under dagen (Figur 1). Detta framkom genom att kombinera olycksdata från STRADA (den nationella databasen) och exponeringsdata för cyklister i Göteborg från 21 mätstationer, exponeringsdata samlas in kontinuerligt och har tillhandahållits för projektet av Göteborgs stad. Figur 1 – Exempel på analys av kombinerade datakällor, olycksdata från STRADA och exponeringsdata från Göteborgs stad.Projektet har bidragit till att ta fram och applicera nya metoder för att utvärdera olycksrisken och relationen mellan olycka och avvärjd olycka. Projektet har även gett nya insikter i arbetet med att utformaåtgärder som ska leda till färre cykelolyckor. Projektet har verifierat och utvidgat tidigare resultat genom att:1)Beskriva cykelolyckor i Göteborg baserat på olycksdata insamlat via rapportering till STRADA (detta inkluderar polis- och sjukhusrapporterad data för singelcykelolyckor och olyckor mellan en cyklist och ett fordon)2)Beskriva cykel vanor, dvs. hur antal cyklister varierar under olika tidsintervall, från exponeringsdata insamlat i Göteborg 3)Kombinera olycksdata från STRADA och exponeringsdata för att:a.Skatta risken vid olika tidpunkterb.Skatta risken för olika geografiska platser4)Kombinera olycks-, exponerings- och naturalistisk data för att avgöra om kritiska händelser från naturalistisk data är relaterat till olyckor Slutsatsen är att exponeringsdata är en nyckelvariabel för den typen av analys för att kunna bedöma risker.Även om tidigare analysresultat och beskrivningar av cykelolyckor i Sverige baserat på data från STRADA, punkt 1, kunde tillämpas enbart på Göteborg, visade sig resultaten från analyserna i punkterna 2-4 vara nya och resulterade i vetenskapliga publikationer. Som ett SAFER associerat projekt rapporterades framskridandet av projektet NoRisk2Bike:s till pre-crash referensgruppen vid SAFER. Data från STRADA gjordes tillgängligt av försäkringsbolaget if, exponeringsdata av Göteborgs stad och naturalistisk cykeldata fanns tillgängligt på SAFER från tidigare projekt (BikeSAFE och e-BikeSAFE) sponsrade av Trafikverket. Genom att skatta olycksrisken geografiskt och med avseende på tidsperiod, adresserade detta projekt, kopplade och kompletterade, alla prioriterade insatsområden i Trafikverkets strategi för säkrare cykling och svarade direkt på det femte prioriterade insatsområdet: utveckla kunskapen om främst olycksrisker och effektsamband.
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| 10. |
- Dozza, Marco, 1978, et al.
(författare)
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Real-world effects of using a phone while driving on lateral and longitudinal control of vehicles
- 2015
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Ingår i: Journal of Safety Research. - : Elsevier BV. - 0022-4375. ; 55,, s. 81-87
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Tidskriftsartikel (refereegranskat)abstract
- Technologies able to augment human communication, such as smartphones, are increasingly present during all daily activities. Their use while driving, in particular, is of great potential concern, because of the high risk that distraction poses during this activity. Current countermeasures to distraction from phone use are considerably different across countries and not always widely accepted/adopted by the drivers.This study utilized naturalistic driving data collected from 108 drivers in the Integrated Vehicle-Based Safety Systems (IVBSS) program in 2009 and 2010 to assess the extent to which using a phone changes lateral or longitudinal control of a vehicle. The IVBSS study included drivers from three age groups: 20-30 (younger), 40-50 (middle-aged), and 60-70 (older). Results from this study show that younger drivers are more likely to use a phone while driving than older and middle-aged drivers. Furthermore, younger drivers exhibited smaller safety margins while using a phone. Nevertheless, younger drivers did not experience more severe lateral/longitudinal threats than older and middle-aged drivers, probably because of faster reaction times. While manipulating the phone (i.e., dialing, texting) drivers exhibited larger lateral safety margins and experienced less severe lateral threats than while conversing on the phone. Finally, longitudinal threats were more critical soon after phone interaction, suggesting that drivers terminate phone interactions when driving becomes more demanding.These findings suggest that drivers are aware of the potential negative effect of phone use on their safety. This awareness guides their decision to engage/disengage in phone use and to increase safety margins (self-regulation). This compensatory behavior may be a natural countermeasure to distraction that is hard to measures in controlled studies. Intelligent systems able to amplify this natural compensatory behavior may become a widely accepted/adopted countermeasure to the potential distraction from phone operation while driving.
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