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  • 1.
    Antonson, Hans
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Ahlström, Christer
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Wiklund, Mats
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Blomqvist, Göran
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Mårdh, Selina
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Crash Barriers and Driver Behavior: A Simulator Study2013In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 14, no 8, p. 874-880Article in journal (Refereed)
    Abstract [en]

    Objective: The study examines how drivers experience a conventional W-beam guardrail (metal crash barrier) along both sides of narrow versus wider roads (single carriageway with 2 lanes) in terms of stress, feelings, and driving patterns and whether subjective experience concurs with the actual driving patterns captured by the quantitative data.

    Methods: The study used different methods to capture data, including the VTI Driving Simulator III (speed and lateral vehicle position) in conjunction with electrocardiogram (ECG) data on heart rate variability (HRV) and questionnaires (oral during driving and written after driving). Eighteen participants-8 men and 10 women-were recruited for the simulator study and the simulator road section was 10 km long.

    Results: Driving speeds increased slightly on the wider road and on the road with a crash barrier, and the lateral driving position was nearer to the road center on the narrower road and on the road with a crash barrier. The HRV data did not indicate that participants experienced greater stress due to road width or due to the presence of a crash barrier. Participant experience captured in the oral questionnaires suggested that road width did not affect driver stress or driving patterns; however, the written questionnaire results supported the simulator data, indicating that a wider road led to increased speed. None of the participants felt that crash barriers made them feel calmer.

    Conclusions: We believe that there is a possibility that the increased speed on roads with crash barriers may be explained by drivers’ sense of increased security. This study demonstrates that an experimental design including experience-based data captured using both a simulator and questionnaires is productive. It also demonstrates that driving simulators can be used to study road features such as crash barriers. It seems more than likely that features such as street lamps, signs, and landscape objects could be tested in this way. © 2013 Copyright Taylor and Francis Group, LLC.

  • 2.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Antonson, Hans
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Ihlström, Jonas
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Stakeholders’ opinions on a future in-vehicle alcohol detection system for prevention of drunk driving2015In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 16, no 4, p. 336-344Article in journal (Refereed)
    Abstract [en]

    Introduction: There is a common understanding that driving under the influence of alcohol is associated with higher risk of being involved in crashes with injuries and possible fatalities as the outcome. Various countermeasures have therefore from time to time been taken by the authorities to prevent drunk driving. One of them has been the alcohol interlock. Up to now, interlocks have mainly been used by previously convicted drunk drivers and in the commercial road transport sector, but not in private cars.

    Objective and Method: New technology has today reached a level where broader implementation might be possible. To our knowledge, however, little is known about different stakeholders' opinions of a broader implementation of such systems. In order to increase that knowledge, we conducted a focus group study to collect in-depth thoughts from different stakeholders on this topic. Eight focus groups representing a broad societal span were recruited and conducted for the purpose.

    Results and Conclusions: The results show that most stakeholders thought that an integrated system for alcohol detection in vehicles might be beneficial in lowering the number of drunk driving crashes. They said that the system would probably mainly prevent driving by people who unintentionally and unknowingly drive under the influence of alcohol. The groups did, however, not regard the system as a final solution to the drunk driving problem, and believed that certain groups, such as criminals and alcoholics, would most likely find a way around the system.

    Concerns were raised about the risk of increased sleepy driving and driving just under the legal blood alcohol concentration (BAC) limit. The results also indicate that stakeholders preferred a system that provides information on the BAC up to the legal limit, but not for levels above the limit; for those, the system should simply prevent the car from starting. Acceptance of the system depended on the reliability of the system, on its ability to perform fast sampling, and on the analytical process, as well as the system's more or less inconspicuous placement and user-friendliness. The stakeholders thought that drivers would probably not voluntarily demand the system. So if broad implementation was desired, it would have to be made compulsory by legislation. As an incentive to increase demand, lower taxes and insurance premiums were suggested.

  • 3.
    Buendia, Ruben
    et al.
    Chalmers University of Technology.
    Forcolin, Fabio
    Chalmers University of Technology.
    Karlsson, Johan
    Autoliv .
    Sjoqvist, Bengt-Arne
    Chalmers University of Technology.
    Anund, Anna
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Driver sleepiness detection in real driving situations2016In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 17, p. 222-223Article in journal (Refereed)
  • 4.
    Buendia, Ruben
    et al.
    Chalmers University of Technology.
    Forcolin, Fabio
    Chalmers University of Technology.
    Karlsson, Johan
    Autoliv.
    Sjöqvist, Bengt Arne
    Chalmers University of Technology.
    Anund, Anna
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Candefjord, Stefan
    Chalmers University of Technology.
    Deriving heart rate variability indices from cardiac monitoring: An indicator of driver sleepiness2019In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957XArticle in journal (Refereed)
    Abstract [en]

    Objective: Driver fatigue is considered to be a major contributor to road traffic crashes. Cardiac monitoring and heart rate variability (HRV) analysis is a candidate method for early and accurate detection of driver sleepiness. This study has 2 objectives: to evaluate the (1) suitability of different preprocessing strategies for detecting and removing outlier heartbeats and spectral transformation of HRV signals and their impact of driver sleepiness assessment and (2) relation between common HRV indices and subjective sleepiness reported by a large number of drivers in real driving situations, for the first time.

    Methods: The study analyzed >3,500 5-min driving epochs from 76 drivers on a public motorway in Sweden. The electrocardiograph (ECG) data were recorded in 3 studies designed to evaluate the physiological differences between awake and sleepy drivers. The drivers reported their perceived level of sleepiness according to the Karolinska Sleepiness Scale (KSS) every 5 min. Two standard methods were used for identifying outlier heartbeats: (1) percentage change (PC), where outliers were defined as interbeat intervals deviating >30% from the mean of the four previous intervals and (2) standard deviation (SD), where outliers were defined as interbeat interval deviating >4 SD from the mean interval duration in the current epoch. Three standard methods were used for spectral transformation, which is needed for deriving HRV indices in the frequency domain: (1) Fourier transform; (2) autoregressive model; and (3) Lomb-Scargle periodogram. Different preprocessing strategies were compared regarding their impact on derivation of common HRV indices and their relation to KSS data distribution, using box plots and statistical tests such as analysis of variance (ANOVA) and Student’s t test.

    Results: The ability of HRV indices to discriminate between alert and sleepy drivers does not differ significantly depending on which outlier detection and spectral transformation methods are used. As expected, with increasing sleepiness, the heart rate decreased, whereas heart rate variability overall increased. Furthermore, HRV parameters representing the parasympathetic branch of the autonomous nervous system increased. An unexpected finding was that parameters representing the sympathetic branch of the autonomous nervous system also increased with increasing KSS level. We hypothesize that this increment was due to stress induced by trying to avoid an incident, because the drivers were in real driving situations.

    Conclusions: The association of HRV indices to KSS did not depend on the preprocessing strategy. No preprocessing method showed superiority for HRV association to driver sleepiness. This was also true for combinations of methods for frequency domain HRV indices. The results prove clear relationships between HRV indices and perceived sleepiness. Thus, HRV analysis shows promise for driver sleepiness detection.

  • 5.
    Carlsson, Anna
    et al.
    Chalmers Tekniska Högskola.
    Chang, Fred
    Humanetics Innovative Solutions, Plymouth, Michigan.
    Lemmen, Paul
    Humanetics Innovative Solutions, Plymouth, Michigan.
    Kullgren, Anders
    Chalmers Tekniska Högskola.
    Schmitt, Kai Uwe
    AGU Zurich, Zurich, Switzerland.
    Linder, Astrid
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Svensson, Mats Y.
    Chalmers Tekniska Högskola.
    Anthropometric Specifications, Development, and Evaluation of EvaRID: A 50th Percentile Female Rear Impact Finite Element Dummy Model2014In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 15, no 8, p. 855-865Article in journal (Refereed)
    Abstract [en]

    Objectives: Whiplash-associated disorders (WADs), or whiplash injuries, due to low-severity vehicle crashes are of great concern in motorized countries and it is well established that the risk of such injuries is higher for females than for males, even in similar crash conditions. Recent protective systems have been shown to be more beneficial for males than for females. Hence, there is a need for improved tools to address female WAD prevention when developing and evaluating the performance of whiplash protection systems. The objective of this study is to develop and evaluate a finite element model of a 50th percentile female rear impact crash test dummy.Methods: The anthropometry of the 50th percentile female was specified based on literature data. The model, called EvaRID (female rear impact dummy), was based on the same design concept as the existing 50th percentile male rear impact dummy, the BioRID II. A scaling approach was developed and the first version, EvaRID V1.0, was implemented. Its dynamic response was compared to female volunteer data from rear impact sled tests.Results: The EvaRID V1.0 model and the volunteer tests compared well until ~250 ms of the head and T1 forward accelerations and rearward linear displacements and of the head rearward angular displacement. Markedly less T1 rearward angular displacement was found for the EvaRID model compared to the female volunteers. Similar results were received for the BioRID II model when comparing simulated responses with experimental data under volunteer loading conditions. The results indicate that the biofidelity of the EvaRID V1.0 and BioRID II FE models have limitations, predominantly in the T1 rearward angular displacement, at low velocity changes (7 km/h). The BioRID II model was validated against dummy test results in a loading range close to consumer test conditions (EuroNCAP) and lower severity levels of volunteer testing were not considered.The EvaRID dummy model demonstrated the potential of becoming a valuable tool when evaluating and developing seats and whiplash protection systems. However, updates of the joint stiffness will be required to provide better correlation at lower load levels. Moreover, the seated posture, curvature of the spine, and head position of 50th percentile female occupants needs to be established and implemented in future models.

  • 6.
    Carlsson, Anna
    et al.
    Chalmers University of Technology, Department of Applied Mechanics, Göteborg, Sweden.
    Linder, Astrid
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Davidsson, Johan
    SAFER - Vehicle and Traffic Safety Centre, Göteborg, Sweden.
    Hell, Wolfram
    Ludwig Maximilian University of Munich, Institute for Legal Medicine, München, Germany.
    Schick, Sylvia
    Ludwig Maximilian University of Munich, Institute for Legal Medicine, München, Germany.
    Svensson, Mats Y.
    Chalmers University of Technology, Department of Applied Mechanics, Göteborg, Sweden.
    Dynamic kinematic responses of female volunteers in rear impacts and comparison to previous male volunteer tests2011In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 12, no 4, p. 347-357Article in journal (Refereed)
    Abstract [en]

    Objectives: The objective was to quantify dynamic responses of 50th percentile females in rear impacts and compare to those from similar tests with males. The results will serve as a basis for future work with models, criteria, and safety systems.

    Methods: A rear impact sled test series with 8 female volunteers was performed at velocity changes of 5 and 7 km/h. The following dynamic response corridors were generated for the head, T1 (first thoracic vertebra) and head relative to T1: (1) accelerations in posterior-anterior direction, (2) horizontal and vertical displacements, (3) angular displacements for 6 females close to the 50th percentile in size. Additionally, the head-to-head restraint distance and contact time and neck injury criterion (NIC) were extracted from the data set. These data were compared to results from previously performed male volunteer tests, representing the 50th percentile male, in equivalent test conditions. T-tests were performed with the statistical significance level of.05 to quantify the significance of the parameter value differences for the males and females.

    Results: At 7 km/h, the females showed 29 percent earlier head-to-head restraint contact time (p =.0072); 27 percent shorter horizontal rearward head displacement (p =.0017); 36 percent narrower head extension angle (p =.0281); and 52 percent lower NIC value (p =.0239) than the males in previous tests. This was mainly due to 35 percent shorter initial head-to-head restraint distance for the females (p =.0125). The peak head acceleration in the posterior-anterior direction was higher and occurred earlier for the females.

    Conclusions: The overall result indicated differences in the dynamic response for the female and male volunteers. The results could be used in developing and evaluating a mechanical and/or mathematical average-sized female dummy model for rear impact safety assessment. These models can be used as a tool in the design of protective systems and for further development and evaluation of injury criteria. © 2011 Taylor & Francis Group, LLC.

  • 7.
    Carlsson, Anna
    et al.
    Chalmers University of Technology, Department of Applied Mechanics, Göteborg, Sweden.
    Siegmund, Gunter P.
    The University of British Columbia, School of Kinesiology, Vancouver, Canada.
    Linder, Astrid
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Svensson, Mats Y.
    Chalmers University of Technology, Department of Applied Mechanics, Göteborg, Sweden.
    Motion of the Head and Neck of Female and Male Volunteers in Rear Impact Car-to-Car Impacts2012In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 13, no 4, p. 378-387Article in journal (Refereed)
    Abstract [en]

    Objectives: The objectives of this study were to quantify and compare dynamic motion responses between 50th percentile female and male volunteers in rear impact tests. These data are fundamental for developing future occupant models for crash safety development and assessment.

    Methods: High-speed video data from a rear impact test series with 21 male and 21 female volunteers at 4 and 8 km/h, originally presented in Siegmund et al. (1997), were used for further analysis. Data from a subset of female volunteers, 12 at 4 km/h and 9 at 8 km/h, were extracted from the original data set to represent the 50th percentile female. Their average height was 163 cm and their average weight was 62 kg. Among the male volunteers, 11 were selected, with an average height of 175 cm and an average weight of 73 kg, to represent the 50th percentile male. Response corridors were generated for the horizontal and angular displacements of the head, T1 (first thoracic vertebra), and the head relative to T1. T-tests were performed with the statistical significance level of.05 to quantify the significance of the differences in parameter values for the males and females.

    Results: Several differences were found in the average motion response of the male and female volunteers at 4 and 8 km/h. Generally, females had smaller rearward horizontal and angular motions of the head and T1 compared to the males. This was mainly due to shorter initial head-to-head restraint distance and earlier head-to-head restraint contact for the females. At 8 km/h, the female volunteers showed 12 percent lower horizontal peak rearward head displacement (P =.018); 22 percent lower horizontal peak rearward head relative to T1 displacement (P =.018); and 30 percent lower peak head extension angle (P =.001). The females also had more pronounced rebound motion.

    Conclusions: This study indicates that there may be characteristic differences in the head-neck motion response between 50th percentile males and females in rear impacts. The exclusive use of 50th percentile male rear impact dummies may thus limit the assessment and development of whiplash prevention systems that adequately protect both male and female occupants. The results of this study could be used in the development and evaluation of a mechanical and/or computational average-sized female dummy model for rear impact safety assessment. These models are used in the development and evaluation of protective systems. It would be of interest to make further studies into seat configurations featuring a greater head-to-head restraint distance. © 2012 Copyright Taylor and Francis Group, LLC.

  • 8.
    Dukic, Tania
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Ahlström, Christer
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Patten, Christopher
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Kettwich, Carmen
    Karlsruhe Institute of Technology.
    Kircher, Katja
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Effects of electronic billboards on driver distraction.2013In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 14, no 5, p. 469-76Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: There is an increase in electronic advertising billboards along major roads, which may cause driver distraction due to the highly conspicuous design of the electronic billboards. Yet limited research on the impact of electronic billboards on driving performance and driver behavior is available. The Swedish Transport Administration recently approved the installation of 12 electronic billboards for a trial period along a 3-lane motorway with heavy traffic running through central Stockholm, Sweden. The aim of this study was to evaluate the effect of these electronic billboards on visual behavior and driving performance.

    METHOD: A total of 41 drivers were recruited to drive an instrumented vehicle passing 4 of the electronic billboards during day and night conditions. A driver was considered visually distracted when looking at a billboard continuously for more than 2 s or if the driver looked away from the road for a high percentage of time. Dependent variables were eye-tracking measures and driving performance measures.

    RESULTS: The visual behavior data showed that drivers had a significantly longer dwell time, a greater number of fixations, and longer maximum fixation duration when driving past an electronic billboard compared to other signs on the same road stretches. No differences were found for the factors day/night, and no effect was found for the driving behavior data.

    CONCLUSION: Electronic billboards have an effect on gaze behavior by attracting more and longer glances than regular traffic signs. Whether the electronic billboards attract too much attention and constitute a traffic safety hazard cannot be answered conclusively based on the present data.

  • 9.
    Eriksson, Jenny
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Forsman, Åsa
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Niska, Anna
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Gustafsson, Susanne
    NTF.
    Sörensen, Gunilla
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    An analysis of cyclists' speed at combined pedestrian and cycle pathsIn: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957XArticle in journal (Refereed)
    Abstract [en]

    Objective: In Sweden, cyclists, pedestrians, and moped riders share the space on combined pedestrian and cycle paths, and their speeds may differ greatly. Both actual speed and speed differences can potentially influence the number of accidents on the shared paths. As a starting point, this article studies the speed component and how cyclists' speed varies at pedestrian and cycle paths depending on the day, week, and year; road user composition; and road design.

    Methods: Three data sources were used: Existing measurements of cycle speed and flow in 3 different Swedish municipalities, Eskilstuna (1 site, January-December 2015), Linkoping (6 sites, 4 weeks in September-October 2015), and Stockholm (10 sites, 1-5 days in August-September 2015); complementary measurements of cycle speed and flow in Linkoping (4 sites, 1-10 days in August-September 2016) and Stockholm (1 site, only part of 2 days in August 2016) were also conducted within the project, in addition to roadside observations of bicycle types at the 5 new sites.

    Results: The average speed of cyclists on the paths varied between 12.5 and 26.5 km/h. As expected, the lower average speeds were found in uphill directions, near intersections, and on paths with high pedestrian flows. The higher speeds were found in downhill directions and on commuter routes. In all, 70%-95% of road users observed on pedestrian and cycle paths were cyclists, and 5%-30% were pedestrians. The most common type of bicycle was a comfort bike, followed by a trekking bike. Electric-assisted bicycles and racer bikes occurred at all sites, with proportions of 1%-10% and 1%-15%, respectively. The 2 sites with the highest proportion of electric-assisted bicycles and racer bicycles also had the highest average speeds. The differences in average speed throughout the day, week, and year could only be assessed at one of the sites. Only small differences were found, with the most noticeable being that the average speed was lower in January and February (13.8 km/h) compared to the rest of the year (15.3-16.1 km/h). The average speed was also lower during daytime (14.7 km/h) than during other parts of the day (15.4-15.8 km/h).

    Conclusions: The relationship between bicycle type and measured speed was not entirely clear, but the results suggest that paths with higher proportions of electric and racer bicycles have higher average speeds. There also appears to be a connection between average speed and the width of the distribution; that is, the higher the average speed, the wider the speed distribution. More research is needed on how speed levels and speed variance affect accident risk.

  • 10.
    Forcolin, Fabio
    et al.
    Chalmers Tekniska Högskola.
    Buendia, Ruben
    Chalmers Tekniska Högskola.
    Candefjord, Stefan
    Chalmers Tekniska Högskola.
    Karlsson, Johan
    Autoliv Development AB.
    Sjoqvist, Bengt Arne
    Chalmers Tekniska Högskola.
    Anund, Anna
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Comparison of outlier heartbeat identification and spectral transformation strategies for deriving heart rate variability indices for drivers at different stages of sleepiness2018In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 19, p. S112-S119Article in journal (Refereed)
    Abstract [en]

    Objective: Appropriate preprocessing for detecting and removing outlier heartbeats and spectral transformation is essential for deriving heart rate variability (HRV) indices from cardiac monitoring data with high accuracy. The objective of this study is to evaluate agreement between standard preprocessing methods for cardiac monitoring data used to detect outlier heartbeats and perform spectral transformation, in relation to estimating HRV indices for drivers at different stages of sleepiness.

    Methods: The study analyzed more than 3,500 5-min driving epochs from 76 drivers on a public motorway in Sweden. Electrocardiography (ECG) data were recorded in 3 studies designed to evaluate the physiological differences between awake and sleepy drivers. The Pan-Tompkins algorithm was used for peak detection of heartbeats from ECG data. Two standard methods were used for identifying outlier heartbeats: (1) percentage change (PC), where outliers were defined as interbeat interval deviating >30% from the mean of the 4 previous intervals, and (2) standard deviation (SD), where outliers were defined as interbeat interval deviating >4 SD from the mean interval duration in the current epoch. Three standard methods were used for spectral transformation, which is needed for deriving HRV indices in the frequency domain; these methods were (1) the Fourier transform; (2) an autoregressive model; and (3) the Lomb-Scargle periodogram. The preprocessing methods were compared quantitatively and by assessing agreement between estimations of 13 common HRV indices using Bland-Altman plots and paired Student's t-tests.

    Results: The PC method detected more than 4times as many outliers (0.28%) than SD (0.065%). Most HRV indices derived using different preprocessing methods exhibited significant systematic (P <.05) and substantial random variations.

    Conclusions: The standard preprocessing methods for HRV data for outlier heartbeat detection and spectral transformation show low levels of agreement. This finding implies that, prior to designing algorithms for detection of sleepy drivers based on HRV analysis, the impact of different preprocessing methods and combinations thereof on driver sleepiness assessment needs to be studied.

  • 11.
    Forsman, Åsa
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Hrelja, Robert
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Henriksson, Per
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Wiklund, Mats
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Co-operation between police and social treatment services offering treatment to drink and drug drivers: experience in Sweden2011In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 12, no 1, p. 9-17Article in journal (Refereed)
    Abstract [en]

    Objective: To describe and analyze a measure that has been introduced in Sweden with the objective of quickly offering treatment for the alcohol or drug problems suspected drink or drug drivers may have. The goal of the measure is that every suspected drink or drug driver shall, as soon as apprehended by the police, be offered contact with the social services or the dependency care and treatment service, which can offer a consultation and, if needed, suitable treatment.

    Method: Interviews and questionnaire surveys, as well as forms that describe the treatment received by each individual case.

    Results: About 20 percent of all those who receive the offer from the police accept contact with the social services or the care and treatment service, and approximately 40 percent of these also attend the consultation. There is a favorable fundamental attitude to the method among the participating authorities. However, some shortcomings in application are revealed. One example concerns drug drivers who are offered contact with the social services or the care and treatment service to a considerably lesser extent than drink drivers. Another neglected group are the people who are at first suspected of drink driving but are later found to have an alcohol concentration below the legal limit. Compared with those who have an alcohol concentration above the legal limit, this group is offered contact to a lesser extent and also have a lower propensity to accept the offer.

    Conclusions: The results indicate a strong support for the method from involved authorities, but participation could be improved by giving more attention to neglected groups.

  • 12.
    Gustafsson, Susanne
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Nyberg, Jonna
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Hrelja, Robert
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    The Swedish Joint Action Method against Drink Driving: A Study of Suspected Drink Drivers' Own Experiences2016In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 17, no 6, p. 558-563Article in journal (Refereed)
    Abstract [en]

    In Sweden, a joint action method called SMADIT is in use, where the police quickly offer help from the social services or the dependency care and treatment service to suspected drink drivers. One conclusion from this paper is that SMADIT, as an innovative method that can be deployed more rapidly than other alcohol-impaired driving countermeasures, should be considered as a good complement to conventional methods to deal with drink driving.

    The objective of this paper is to analyse the experiences of suspected drink drivers who accepted the offer of help, and what it meant for them. To enable comparisons over time, in-depth interviews were conducted with twelve suspected drink drivers on two occasions with one year between.

    To varying degrees the informants knew about their alcohol problems, but were unsure if they would have sought help by themselves. Therefore, the original ideas of the method with an initial contact with the social services or the dependency care and treatment service within 24 hours, was found to be important. However, the results also showed that some of the informants needed some time before the first meeting as they were in shock from the drink driving incident or in need of sleep.

    Results also shows that an encouraging attitude among the police, the social services, and the dependency care and treatment service is important for the success of the SMADIT method. The informants are satisfied with the method, and in retrospect the incident and the SMADIT offer of help are described as a turning point in their lives. One year after being offered help the informants had gained insights into the harm they could have done to other road users when they drove while drunk.

  • 13.
    Kircher, Katja
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Andersson, Jan
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Truck drivers' opinion on road safety in Tanzania: A questionnaire study2012In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 14, no 1, p. 103-111Article in journal (Refereed)
    Abstract [en]

    Even though the traffic fatality risk (fatalities per 100 000 inhabitants) in Tanzania is quite low, the fatality rate (fatalities per 10 000 vehicles) is one of the highest in the world. Since vehicle density will increase it is important to implement measures to increase traffic safety.

    Within the EU project ASSET-Road a questionnaire study on road safety was conducted with 250 truck drivers in Tanzania. The drivers were interviewed in three different towns in southern Tanzania, and participation was voluntary. The questionnaire treated demographics, the state of the drivers' vehicles, the frequency of breakdowns and the maintenance of the vehicles. Further questions concerned driver behaviour, crash involvement, crash risk and crash mitigation.

    Truck drivers reported to drive 10.6 hours without break on average, with several drivers reporting that they had to drive 24 hours without rest. Around 40% of the trucks did not have any seat belts installed, with a larger share of older trucks lacking belts. Most of the drivers who had seat belts reported to use them, however. Almost 40% of the drivers reported to have been involved in at least one crash, and 45% of those drivers had experienced fatal crashes. This underlines that crashes counted per vehicle are very frequent, and the results are often severe, especially when heavy vehicles are involved.

    When asked what the three most common crash causes were, driver related causes were named frequently. Drivers were said to be reckless, further crash causes named often were drunkenness, inattention and sleepiness. One of the most mentioned crash mitigation strategies was driver education, but also improvement of the roads and the vehicles.

  • 14.
    Linder, Astrid
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Carlsson, Anna
    Swedish National Road and Transport Research Institute.
    Svensson, Mats Y
    Chalmers University of Technology.
    Siegmund, Gunter P.
    The University of British Columbia.
    Dynamic responses of female and male volunteers in rear impacts2008In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 9, no 6, p. 592-599Article in journal (Refereed)
    Abstract [en]

    Objectives: Whiplash injuries from vehicle collisions are common and costly. These injuries most frequently occur as a result of a rear impact and, compared to males, females have up to twice the risk of whiplash-associated disorders (WAD) resulting from vehicle crashes. The present study focuses on the differences in the dynamic response corridors of males and females in low-severity rear impacts.

    Methods: In this study, analysis of data from volunteer tests of females from previously published data has been performed. Corridors for the average female response were generated based on 12 volunteers exposed to a change of velocity of 4 km/h and 9 volunteers exposed to a change of velocity of 8 km/h. These corridors were compared to corridors for the average male response that were previously generated based on 11 male volunteers exposed to the same test conditions.

    Results: Comparison between the male and female data showed that the maximum x-acceleration of the head for the females occurred on average 10 ms earlier and was 29% higher during the 4 km/h test and 12 ms earlier and 9% higher during the 8 km/h test. Head-to-head restraint contact for the females occurred 14 ms earlier at 4 km/h and 11 ms earlier at 8 km/h compared to the males. For the same initial head-to-head restraint distance, head restraint contact occurred 11 and 7 ms earlier for the females than the males at 4 and 8 km/h, respectively. Furthermore, the calculated Neck Injury Criteria (NIC) values were similar for males and females at 4 km/h, whereas they were lower for females compared to the males at 8 km/h (3.2 and 4.0 m2/s2, respectively).

    Conclusions: The results of this study highlight the need to further investigate the differences in dynamic responses between males and females at low-severity impacts. Such data are fundamental for the development of future computer models and dummies for crash safety assessment. These models can be used not only as a tool in the design and development process of protective systems but also in the process of further evaluation and development of injury criteria. Copyright © 2008 Taylor & Francis Group, LLC.

  • 15.
    Linder, Astrid
    et al.
    Chalmers University of Technology.
    Svensson, Mats Y.
    Chalmers University of Technology.
    Davidsson, Johan
    Chalmers University of Technology.
    Flogård, Anders
    Chalmers University of Technology.
    Lövsund, Per
    Chalmers University of Technology.
    Håland, Yngve
    Autoliv Inc., Stockholm, Sweden.
    Jakobsson, Lotta
    Volvo Car Corporation.
    Wiklund, Kristina
    Saab Automobile AB.
    Design and validation of the neck for a rear impact dummy (BioRID I)2002In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 3, no 2, p. 167-174Article in journal (Refereed)
    Abstract [en]

    To assess the protective performance of seats and head restraints, occupant models able to mimic the motion of a human in a crash are needed. Hence, a new mechanical dummy neck for low-velocity rear collision tests was developed. The dummy neck consists of seven cervical elements connected by pin joints. The stiffness properties of the neck were represented by rubber blocks mounted between each pair of vertebrae, as well as by muscle substitutes between the head and the first thoracic vertebra (T1). The muscle substitutes consist of cables connected to a unit containing springs and a damper. The neck was validated against volunteer test data (Δv of 7 km/h) and compared with the kinematics of the Hybrid III dummy. The new neck was tested as a part of a new dummy (BioRID) that produced a human-like motion of the T1. The kinematics of the new neck was within the corridor of the volunteers, during the major part of the first 250 ms of the crash event, for both displacement of the head relative to T1 and for the acceleration of the head. This applies to both duration and peak values. When compared with the new neck, the Hybrid III showed an earlier decrease of the horizontal acceleration of the head, less maximum horizontal displacement, and an earlier increase of the rearward angular displacement of the head relative to T1.

  • 16.
    Linder, Astrid
    et al.
    Chalmers University of Technology.
    Svensson, Mats Y.
    Chalmers University of Technology, Department of Applied Mechanics, Göteborg, Sweden.
    Viano, David C.
    Wayne State University, Department of Biomedical Engineering, Detroit, United States.
    Evaluation of the BioRID P3 and the hybrid III in pendulum impacts to the back: A comparison with human subject test data2002In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 3, no 2, p. 159-166Article in journal (Refereed)
    Abstract [en]

    Crash test dummies able to mimic the motion of a human are needed to assess the protective performance of seats and head restraints in crash tests. This study evaluates both a newly developed dummy for rear impacts (BioRID P3) and the Hybrid III dummy by means of a recently available set of human subject data. The study also meets the need for validation of the BioRID P3 at a higher impact severity than that previously achieved. The BioRID P3 and the Hybrid III were evaluated by means of pendulum impacts to the back and compared with data from previously run cadaver tests. Seated dummies were struck with a pendulum with a mass of 23 kg and an impact velocity of 4.6 m/s at the level of the 6th thoracic vertebra. The results showed that peak values and temporal responses of the BioRID P3 was closer to that of the corridor of the cadavers than the Hybrid III in terms of horizontal, vertical, and angular displacement of the head and of the head relative to T1.

  • 17.
    Mårdh, Selina
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Mårdh, Pamela
    Region Östergötland.
    Anund, Anna
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Driving restrictions post-stroke: Physicians' compliance with regulations2017In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, p. 1-4Article in journal (Refereed)
    Abstract [en]

    Objective: Suffering a stroke might lead to permanent cognitive and/or physical impairment. It has been shown that these impairments could have an impact on an individual's fitness to drive. In Sweden, as in many other countries, there are regulations on driving cessation post-stroke. Information on driving cessation should be given to all patients and noted in the journal.The present study sought to determine physician's compliance to driving regulations post-stroke as well as follow-up and gender aspects.

    Method: A retrospective study of medical records on stroke patients was carried out. The study covered all of the medical records on stroke incidents (n = 342) during a year at a typical medium to large-sized hospital in Sweden.

    Results: A journal entry on driving cessation post-stroke was missing in 81% of the medical records. Only 2% of the patients were scheduled for a follow-up meeting specifically concerning fitness to drive. Significantly more men than women had an entry on driving in the journal.

    Conclusions: We conclude that the Swedish regulations on driving cessation post-stroke were not followed at the participating hospital. It is crucial that all stroke patients receive information on driving cessation because their condition might affect fitness to drive. Analysis of follow-up records showed that there was no consistent method for assessment of a patient's fitness to drive. There was also a gender difference in the material, which warrants further investigation.

  • 18.
    Niska, Anna
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Wenäll, Jan
    Swedish National Road and Transport Research Institute, Infrastructure, Crash safety.
    Simulated single-bicycle crashes in the VTI crash safety laboratory2019In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957XArticle in journal (Refereed)
    Abstract [en]

    Objective: The objective of this study was to examine the influence of bicycle design and speed on the head impact when suffering from a single-bicycle crash, and the possibility to study this using crash tests.

    Methods: Simulations of single-bicycle crashes were performed in the VTI crash safety laboratory. Two bicycle crash scenarios were simulated: "a sudden stop" and "sideways dislocation of the front wheel"; using four different bicycle types: a "lady's bicycle", a commuter bicycle, a recumbent bicycle and a pedelec; at two speeds: 15 and 25 km/h. In addition, sideway falls were performed with the bicycles standing still. All tests were done with a Hybrid II 50(th) percentile crash test dummy placed in the saddle of the bicycles, with acceleration measurements in the head.

    Results: The crash tests showed that a sudden stop, e.g. a stick or bag in the front wheel, will result in a falling motion over the handle bars causing a forceful head impact while a sideways dislocation of the front wheel will result in a falling motion to the side causing a more moderate head impact. The falling motion varies between the different bicycle types depending on crash test scenario and speed. The pedelec had a clearly different falling motion from the other bicycle types, especially at a sudden stop.

    Conclusions: The study implies that it is possible to examine single-bicycle crashes using crash tests, even though the setup is sensitive to minor input differences and the random variation in the resulting head impact values can be large. Sideway falls with the bicycles standing still were easier to perform with a good repeatability and indicated an influence of seating height on the head impact.

  • 19.
    Ohlin, Maria
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Alguren, Beatrix
    Göteborgs Universitet.
    Lie, Anders
    Chalmers Tekniska Högskola.
    Analysis of bicycle crashes in Sweden involving injuries with high risk of health loss2019In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 10, no 1Article in journal (Refereed)
    Abstract [en]

    Objective: The objectives of the present article were to (a) describe the main characteristics of bicycle crashes with regard to the road environment, crash opponent, cyclist, and crash dynamics; (b) compare individuals who describe their health after the crash as declined with those who describe their health as not affected; and (c) compare the number of injured cyclists who describe their health as declined after the crash with the predicted number of permanent medical impairments within the same population.

    Methods: A sample of individuals with specific injury diagnoses was drawn from the Swedish Traffic Accident Data Acquisition (STRADA) database (n = 2,678). A survey form was used to collect additional information about the crash and the health-related outcomes. The predicted number of impaired individuals was calculated by accumulating the risk for all individuals to sustain at least a 1% permanent medical impairment, based on the injured body region and injury severity.

    Results: Nine hundred forty-seven individuals (36%) responded, of whom 44% reported declined health after the crash. The majority (68%) were injured in single bicycle crashes, 17% in collisions with motor vehicles, and 11% in collisions with another cyclist or pedestrian. Most single bicycle crashes related to loss of control (46%), mainly due to skidding on winter surface conditions (14%), followed by loss of control during braking (6%). There was no significant difference in crash distribution comparing all crashes with crashes among people with declined health. The predicted number of impaired individuals (n = 427) corresponded well with the number of individuals self-reporting declined health (n = 421).

    Conclusions: The types of crashes leading to health loss do not substantially differ from those that do not result in health loss. Two thirds of injuries leading to health loss occur in single bicycle crashes. In addition to separating cyclists from motorized traffic, other preventive strategies are needed.

  • 20.
    Putra, I. Putu A.
    et al.
    Chalmers University of Technology.
    Iraeus, Johan
    Chalmers University of Technology.
    Thomson, Robert
    Chalmers University of Technology.
    Svensson, Mats Y.
    Chalmers University of Technology.
    Linder, Astrid
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System. Chalmers University of Technology.
    Sato, Fusako
    Chalmers University of Technology.
    Comparison of control strategies for the cervical muscles of an average female head-neck finite element model2019In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957XArticle in journal (Refereed)
    Abstract [en]

    Objective: ViVA OpenHBM is the first open source Human Body Model (HBM) for crash safety assessment. It represents an average size (50th percentile) female and was created to assess whiplash protection systems in a car. To increase the biofidelity of the current model, further enhancements are being made by implementing muscle reflex response capabilities as cervical muscles alter the head and neck kinematics of the occupant during low-speed rear crashes. The objective of this study was to assess how different neck muscle activation control strategies affect head-neck kinematics in low speed rear impacts.

    Methods: The VIVA OpenHBM head-neck model, previously validated to PMHS data, was used for this study. To represent the 34 cervical muscles, 129 beam elements with Hill-type material models were used. Two different muscle activation control strategies were implemented: a control strategy to mimic neural feedback from the vestibular system and a control strategy to represent displacement feedback from muscle spindles. To identify control gain values for these controller strategies, parameter calibrations were conducted using optimization. The objective of these optimizations was to match the head linear and angular displacements measured in volunteer tests.

    Results: Muscle activation changed the head kinematics by reducing the peak linear displacements, as compared to the model without muscle activation. For the muscle activation model mimicking the human vestibular system, a good agreement was observed for the horizontal head translation. However, in the vertical direction there was a discrepancy of head kinematic response caused by buckling of the cervical spine. In the model with a control strategy that represents muscle spindle feedback, improvements in translational head kinematics were observed and less cervical spine buckling was observed. Although, the overall kinematic responses were better in the first strategy.

    Conclusions: Both muscle control strategies improved the head kinematics compared to the passive model and comparable to the volunteer kinematics responses with overall better agreement achieved by the model with active muscles mimicking the human vestibular system.

  • 21.
    Radun, Igor
    et al.
    University of Helsinki.
    Ahlström, Christer
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Letter to the Editor: Electronic Billboards and Driver Distraction2013In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 14, no 5, p. 554-555Article in journal (Other (popular science, discussion, etc.))
  • 22.
    Vadeby, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Forsman, Åsa
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Evaluation of New Speed Limits in Sweden: A Sample Survey2014In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 15, no 8, p. 778-785Article in journal (Refereed)
    Abstract [en]

    The study sought to estimate changes in actual driving speed occurring after new speed limits were introduced in Sweden’s rural road network. The effects of speed limit changes were estimated for 7 groups of roads of different types and initial speed limits. To study the effects on the entire road network and not only at specific road sites, a sampling survey was conducted in which speed was measured at randomly selected sites before and after the speed limit changes.

    Systematic sampling was used to select sites that were widely distributed geographically, though the analysis treats the data as if the sites were selected by simple random sampling. The speed of passing vehicles was generally measured using pneumatic tubes stretched across the road.

    The survey results indicate that the mean car speed increased by 3.5 km/h when the speed limit increased by 10 km/h on motorways and 2 + 1 roads. Reducing the speed limit by 10 km/h on 2 + 1 roads and rural roads with a speed limit of 110 km/h resulted in a 2 km/h decrease in mean speed. On rural roads where the speed limit was lowered from 90 to 80 km/h, the mean speed decreased by 3.3 km/h. These changes are statistically significant.

    The present results are in line with previous results indicating an average change in mean speed of approximately 2.5 km/h when the speed limit changes by 10 km/h. The confidence intervals were in most instances fairly small, indicating a sufficiently large number of measurement sites.

  • 23.
    Valen, Anja
    et al.
    Oslo University Hospital.
    Bogstrand, Stig Tore
    Oslo University Hospital.
    Vindenes, Vigdis
    Oslo University Hospital.
    Frost, Joachim
    St. Olav University Hospital.
    Larsson, Magnus
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Holtan, Anders
    Gjerde, Hallvard
    Oslo University Hospital.
    Fatally injured drivers in Norway 2005–2015: Trends in substance use and crash characteristics2019In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 20, no 5, p. 460-466Article in journal (Refereed)
    Abstract [en]

    Objective: Norway introduced a “Vision Zero” strategy in 2001, using multiple approaches, aiming toward a future in which no one will be killed or seriously injured in road traffic crashes (RTCs). Official statistics show that the number of fatally injured road users has declined substantially from 341 deaths in 2000 to 117 in 2015. In-depth crash investigations of all fatal RTCs started in Norway in 2005. The aim of this study was to investigate whether fatal crash characteristics, vehicle safety features, and prevalence of drugs and/or alcohol among fatally injured drivers and riders has changed during 2005–2015, accompanying the reduction in road fatalities.

    Methods: Data on all car/van drivers and motorcycle/moped riders fatally injured in RTCs during 2005–2015 were extracted from Norwegian road traffic crash registries and combined with forensic toxicology data.

    Results: The proportion of cars and motorcycles with antilock braking systems and cars with electronic stability control, increased significantly during the study period. The prevalence of nonuse of seat belts/helmets and speeding declined among both fatally injured drivers and riders. In addition, the prevalence of alcohol declined, though no significant change in the total prevalence of other substances was noted.

    Conclusion: The observed changes toward more safety installations in cars and motorcycles and lower prevalence of driver-related risk factors like alcohol use, speeding, and nonuse of seat belts/helmets among fatally injured drivers/riders may have contributed to the decrease in road traffic deaths.

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