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Östermalm, Sweden

Rosen E.,Autoliv | Stigson H.,Karolinska Institutet | Stigson H.,Folksam Research | Sander U.,Autoliv
Accident Analysis and Prevention | Year: 2011

The aim of this review was to evaluate all studies of pedestrian fatality risk as a function of car impact speed. Relevant papers were primarily investigated with respect to data sampling procedures and methods for statistical analysis. It was uniformly reported that fatality risk increased monotonically with car impact speed. However, the absolute risk estimates varied considerably. Without exceptions, papers written before 2000 were based on direct analyses of data that had a large bias towards severe and fatal injuries. The consequence was to overestimate the fatality risks. We also found more recent research based on less biased data or adjusted for bias. While still showing a steep increase of risk with impact speed, these later papers provided substantially lower risk estimates than had been previously reported. © 2010 Elsevier Ltd. Source

Fredriksson R.,Karolinska Institutet | Fredriksson R.,Autoliv | Rosen E.,Autoliv | Kullgren A.,Karolinska Institutet | Kullgren A.,Folksam Research
Accident Analysis and Prevention | Year: 2010

The aim of this study was to aid the optimisation of future, vehicle based, pedestrian injury countermeasures. The German In-Depth Accident Study (GIDAS) database was queried for pedestrians impacted by the front of a passenger car or van. A total of 1030 cases from 1998 to 2008 were studied including 161 severely (AIS3+) injured pedestrians. Considering the severe injuries, the most frequent injury mechanisms were "leg-to-front end", "head-to-windscreen area", "chest-to-bonnet area", and "chest-to-windscreen area". For children, a "head-to-bonnet area" impact was the second most common source of injury. With safety systems targeting these five injury mechanisms, 73% (95% confidence interval [CI], 65-81%) of the severely injured pedestrians would be provided protection from all of their vehicle-induced severe injuries. Omitting the windscreen area, this figure is decreased to 44% (CI, 36-53%). Furthermore, 31% of the surviving pedestrians were estimated to sustain a permanent medical impairment at any level. For more severe impairment, head was the dominating body region. The study shows that when developing countermeasures for the windscreen area to mitigate head injuries, attention should be paid to the structural parts of the windscreen area with a special focus on brain injuries. Finally, the incidence and risk of severe injury were derived as functions of impact speed for different body regions and injury sources. © 2010 Elsevier Ltd. All rights reserved. Source

Tingvall C.,Monash University | Stigson H.,Karolinska Institutet | Krafft M.,Folksam Research | Lie A.,Karolinska Institutet
Accident Analysis and Prevention | Year: 2010

Road traffic Safety Performance Indicators (SPIs) are becoming increasingly used as an instrument for the planning and monitoring of safety progress. SPIs form an intermediate step between actions and final outcome in terms of casualties in road crashes. It is understood that SPIs are closely related to outcome; and that it is also possible to use them in calculations and predictions of both actions and final outcome. In the present study, it was found that some of the properties assigned to SPIs could be questioned. An assumption of linearity between SPIs and final outcome was partly rejected. It was also found that 100% fulfillment of a set of SPIs could lead to very low mortality, demonstrating the importance of handling SPIs simultaneously. © 2009 Elsevier Ltd. All rights reserved. Source

Rizzi M.,Folksam Research | Rizzi M.,Chalmers University of Technology | Strandroth J.,Chalmers University of Technology | Holst J.,Chalmers University of Technology | Tingvall C.,Norwegian Public Roads Administration
Traffic Injury Prevention | Year: 2016

Objective: This research investigated the following issue. Though several tests indicate that motorcycle ABS may increase motorcycle stability, thus reducing the risk of a sliding crash involving braking (i.e., the rider is separated from the motorcycle and slides along the road surface prior to collision), there is limited research showing to what extent sliding crashes are reduced by ABS in real-life conditions. Methods: The Swedish Transport Administration (STA) and the Norwegian Public Roads Administration (NPRA) carry out in-depth studies for all road fatalities. A total of 38 in-depth studies with ABS motorcycles were included: 22 in Sweden and 16 in Norway (2005–2014). These were compared with 98 cases in Sweden and 32 in Norway involving motorcycles of the same types but without ABS. The data sets were analyzed separately and also merged together. The difference between the proportions of sliding crashes regardless braking was analyzed; selective recruitment was handled with a sensitivity analysis. Induced exposure was used to calculate the reduction of all crashes and those involving braking. Results: Four ABS cases (11%) involved falling off the motorcycle prior to collision, and 35% of the non-ABS crashes were sliding (P =.004). The sensitivity analysis showed that the results were stable, with a relative difference of sliding crashes ranging between 65 and 78%. None of the 4 sliding crashes with ABS occurred during braking; that is, all ABS riders who braked prior to collision crashed in an upright position. In the 4 sliding cases with ABS, the riders lost control of their motorcycles: 2 while accelerating on asphalt with very poor friction, 1 while negotiating a curve with an excessive lean angle, and 1 by abruptly releasing the throttle in the middle of a curve. Although based on a limited number of cases, the distributions of sliding and upright collisions among crashes without braking were similar, thus suggesting that the crash posture would not be affected by ABS if no braking occurred. The calculations with induced exposure showed that upright crashes with braking were also reduced by ABS; all fatal crashes, regardless of braking, were reduced by 52%. Conclusions: Though this research was based on a limited material, it confirmed that sliding fatal crashes are significantly decreased by ABS. Considering that ABS will soon be mandatory in the European Union on all new motorcycles with engine displacement over 125cc, these findings should be taken into account in the future design and testing of motorcycle-friendly road barriers and integrated protection systems. © 2016 Taylor & Francis Group, LLC. Source

Sunnevang C.,Autoliv | Bostrom O.,Autoliv | Lie A.,Karolinska Institutet | Stigson H.,Karolinska Institutet | Stigson H.,Folksam Research
Traffic Injury Prevention | Year: 2011

Objective: Intersections are challenging for many road users. According to US, European, and global statistics, intersectionrelated crashes with fatal outcome represent approximately 20 percent of all traffic fatalities. The aim of this study was to use Swedish data to investigate and characterize fatal car-to-car intersection crashes for modern cars equipped with frontal and side air bags. Method: The Swedish Transport Administration (STA) national database on fatal crashes was searched to find vehicleto- vehicle intersection crashes involving modern cars that occurred between 2003 and 2009 that resulted in fatal injuries for at least one of the involved passengers. From all intersection crashes, the car-to-car crashes from the sample were analyzed at an occupant level. Occupant location in the target vehicle with respect to impact direction as well as AIS3+ injuries to body regions was examined for the total car-to-car sample. Crashes involving a target vehicle equipped with front and side air bags were then selected for an in-depth study. Results: In the STA database, 39 vehicle-to-vehicle crashes matched the search criteria. Of 39 crashes, 17 involved a heavy goods vehicle (HGV) as the striking vehicle, and 17 were car-to-car crashes. All car-to-car crashes were side impacts, occurring at rural intersections, involving 20 (12 female and 8 male) fatally injured occupants, 15 of whom were 61 years or older and classified as senior occupants. A majority of fatally injured occupants sustained combined AIS3+ injuries to more than one body region. Conclusions: All modern car-to-car crashes with a fatal outcome occurring at Swedish intersections from 2003 to 2009 were side impacts. The crashes were characterized by a senior front seat driver, traveling with a front seat passenger, hit on the left side at approximately 70 km/h. In this study all fatal crashes occurred at severities beyond those currently evaluated in side impact rating procedures but were within survivable limits for a non-senior occupant in a majority of cases. © 2011 Taylor & Francis Group, LLC. Source

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