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Tingvall C.,Swedish Road Administration | Tingvall C.,Monash University | Stigson H.,Karolinska Institutet | Eriksson L.,Swedish Road Administration | And 4 more authors.
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.

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.

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.

Stigson H.,Folksam Research | Stigson H.,Karolinska Institutet | Hagberg J.,Karolinska Institutet | Kullgren A.,Folksam Research | And 3 more authors.
Traffic Injury Prevention | Year: 2014

Objective: The objective was to identify whether it was possible to change driver behavior by economic incentives and thereby reduce crash risk. Furthermore, the objective was to evaluate the participants' attitudes toward the pay-as-you-speed (PAYS) concept.Methods: A one-year PAYS trial with economic incentives for keeping speed limits using intelligent speed assistance (ISA) was conducted in Sweden during 2011-2012. The full incentive was a 30 percent discount off the insurance premium. The participants were private insurance customers and were randomized into a test group (initial n = 152, final n = 128) and a control group (initial n = 98, final n = 68). When driving, the drivers in the test group were informed and warned visually when the speed limit was exceeded. They could also follow their driving results on a personal website. The control group was not given any feedback at all. To reflect the impact of the PAYS concept the proportion of distance driven above the speed limit was compared between the 2 groups.Results: The introduction of a PAYS concept shows that the test group significantly reduced the proportion of distance driven above the speed limit. The proportion of driving at a speed exceeding 5 km/h over the speed limit was 6 percent for the test group and 14 percent for the control group. It also showed that the effect was higher the higher the violation of speed. The result remained constant over time.Conclusions: It was shown that a PAYS concept is an effective way to reduce speed violations. Hence, it has the possibility to reduce crash severity and thereby to save lives. This could be an important step toward a safer road transport system. The majority of the participants were in favor of the concept, which indicates the potential of a new insurance product in the future. © 2014 Taylor & Francis Group, LLC.

Bohman K.,Autoliv | Bohman K.,Karolinska Institutet | Stigson H.,Karolinska Institutet | Stigson H.,Folksam Research | And 2 more authors.
Traffic Injury Prevention | Year: 2014

Objective: There is limited knowledge of the long-term medical consequences for children injured in car crashes. Thus, in the event of injury, the aim of the study was to specify patterns and risks of injuries resulting in permanent medical impairment of children (0-12 years) for different body regions and injury severity levels, according to Abbreviated Injury Scale (AIS). The aim was also to compare the impairment outcome with adults. Methods: Data were obtained from the Folksam insurance company, including reported car crashes from 1998 to 2010 with at least one injured child 0-12 years of age. In all, 2619 injured children with 3704 reported medical diagnoses were identified. All injuries were classified according to the AIS 2005 revision. If the child had not recovered within 1 year postinjury an assessment of permanent medical impairment (PMI) was made by one or several medical specialists. Results: In all, 55 children sustained 59 injuries resulting in PMI of which 75 percent were at AIS 1 or AIS 2. The head and cervical spine were the body regions sustaining the most injuries resulting in PMI. Sixty-eight percent of all injuries resulting in PMI were AIS 1 injuries to the cervical spine, with the majority occurring in frontal or rear impacts. Given an injury to the cervical spine, the risk of injuries resulting in PMI was 3 percent, and older children (≥6 years) had a significantly higher risk (3% versus 1%) than younger children. The head was the second most commonly injured body region with injuries resulting in PMI (12/59), which were predominantly AIS 2+. In addition, mild traumatic brain injuries at AIS 1 were found to lead to PMI. Whereas for children the injuries leading to PMI were primarily limited to the head and cervical spine, adults sustained injuries that led to PMI from a more diverse distribution of body regions. Conclusion: The pattern of injuries resulting in permanent medical impairment is different for children and adults; therefore, safety priorities for children need to be based on child data. The majority of those injuries leading to PMI were at lower AIS levels. Furthermore, AIS 1 cervical spine and AIS 1+ head injuries should be given priority concerning mitigation of long-term consequences for children. © 2014 Copyright Taylor and Francis Group, LLC.

Gustafsson M.,Umeå University | Stigson H.,Folksam Research | Stigson H.,Karolinska Institutet | Krafft M.,Umeå University | And 3 more authors.
Traffic Injury Prevention | Year: 2015

Objective: As fatalities from car crashes decrease, focus on medical impairment following car crashes becomes more essential. This study assessed the risk of permanent medical impairment based on car occupant injuries. The aim was to study whether the risk of permanent medical impairment differs depending on age and gender.Methods: In total, 36,744 injured occupants in car crashes that occurred between 1995 and 2010 were included. All initial injuries (n = 61,440) were classified according to the Abbreviated Injury Scale (AIS) 2005. If a car occupant still had residual symptoms 3 years after a crash, the case was classed as a permanent medical impairment. In total, 5,144 injuries led to permanent medical impairment. The data were divided into different groups according to age and gender as well as levels of permanent impairment. The risk of permanent medical impairment was established for different body regions and injury severity levels, according to the AIS.Results: The cervical spine was the body region that had the highest number of diagnoses, and occupants who sustained injuries to the upper and lower extremities had the highest risk of medical impairment for both genders. Females aged 60 and above had a higher risk of permanent medical impairment from fractures in the extremities compared to males in the same age group and younger females. Females aged 44 or younger had a higher risk of permanent medical impairment from whiplash-associated disorders (WAD) than males in the same age group. Minor and moderate injuries (AIS 1–2) had a higher risk of permanent medical impairment among older car occupants compared to younger ones.Conclusions: Differences in long-term outcome were dependent on both gender and age. Differences between age groups were generally greater than between genders. The vast majority of permanent medical impairments resulted from diagnoses with a low risk of fatality. The results emphasize the impact of age and gender in long-term consequences from car crashes. They could be used when designing safety technology in cars as well as to improve health care by contributing to better allocation of rehabilitation resources following trauma. © 2015, Copyright © Taylor & Francis Group, LLC.

Stigson H.,Folksam Research | Stigson H.,Karolinska Institutet | Kullgren A.,Folksam Research | Kullgren A.,Chalmers University of Technology | Rosen E.,Autoliv
Annals of Advances in Automotive Medicine | Year: 2012

Knowledge of how crash severity influences injury risk in car crashes is essential in order to create a safe road transport system. Analyses of real-world crashes increase the ability to obtain such knowledge. The aim of this study was to present injury risk functions based on real-world frontal crashes where crash severity was measured with on-board crash pulse recorders. Results from 489 frontal car crashes (26 models of four car makes) with recorded acceleration-time history were analysed. Injury risk functions for restrained front seat occupants were generated for maximum AIS value of two or greater (MAIS2+) using multiple logistic regression. Analytical as well as empirical injury risk was plotted for several crash severity parameters; change of velocity, mean acceleration and peak acceleration. In addition to crash severity, the influence of occupant age and gender was investigated. A strong dependence between injury risk and crash severity was found. The risk curves reflect that small changes in crash severity may have a considerable influence on the risk of injury. Mean acceleration, followed by change of velocity, was found to be the single variable that best explained the risk of being injured (MAIS2+) in a crash. Furthermore, all three crash severity parameters were found to predict injury better than age and gender. However, age was an important factor. The very best model describing MAIS2+ injury risk included delta V supplemented by an interaction term of peak acceleration and age. ©Annals of Advances in Automotive Medicine.

Kullgren A.,Folksam Research | Kullgren A.,Karolinska Institutet | Krafft M.,Folksam Research
International Research Council on the Biomechanics of Injury - 2010 International IRCOBI Conference on the Biomechanics of Injury, Proceedings | Year: 2010

The objective was to study the effectiveness of whiplash protection concepts in cars due to gender and the effectiveness of various concepts based on real-world injury outcome. In the study the influence on whiplash symptoms lasting longer than one month and those leading to permanent medical impairment was studied. In average the existing whiplash concepts were more effective for males than females. The risk reduction regarding permanent medical impairment was approximately 45% for females and approximately 60% for males. RHR in Saab, Volvo WHIPS and Toyota WIL, all had approximately 50% lower risk of whiplash injuries leading to permanent medical impairment compared to cars with standard seats.

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.

PubMed | Folksam Research and Chalmers University of Technology
Type: | Journal: Accident; analysis and prevention | Year: 2017

Several studies have estimated the health effects of active commuting, where a transport mode shift from car to bicycle reduces risk of mortality and morbidity. Previous studies mainly assess the negative aspects of bicycling by referring to fatalities or police reported injuries. However, most bicycle crashes are not reported by the police and therefore hospital reported data would cover a much higher rate of injuries from bicycle crashes. The aim of the present study was to estimate the effect on injuries and fatalities from traffic crashes when shifting mode of transport from car to bicycle by using hospital reported data.This present study models the change in number of injuries and fatalities due to a transport mode change using a given flow change from car to bicycle and current injury and fatality risk per distance for bicyclists and car that bicyclists have a much higher injury risk (29 times) and fatality risk (10 times) than car occupants. In a scenario where car occupants in Stockholm living close to their work place shifts transport mode to bicycling, injuries, fatalities and health loss expressed in Disability-Adjusted Life Years (DALY) were estimated to increase. The vast majority of the estimated DALY increase was caused by severe injuries and fatalities and it tends to fluctuate so that the number of severe crashes may exceed the estimation with a large margin.Although the estimated increase of traffic crashes and DALY, a transport mode shift is seen as a way towards a more sustainable society. Thus, this present study highlights the need of strategic preventive measures in order to minimize the negative impacts from increased bicycling.

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