Sonstige
The number of injuries sustained by car occupants involving the head, thorax, spine, pelvis and the upper limbs have been reduced significantly during recent years. This is probably due to better safety features in the cars, especially the availability and usage of safety belts, airbags etc. Therefore one can notice clinically a relative increase in survivors of severe frontal crashes, but many of them have injuries to the lower extremities. To verify this, we analyzed the foot and ankle injuries of front seat passengers.
Sedan type vehicles in which adult rear seat passengers were present and which were involved in frontal collisions were investigated, and the influence of unbelted rear seat passengers on the injuries of front seat occupants was studied. Unbelted rear seat passengers move forward during impact. It was observed that there were not only cases in which front seat occupants sustained injuries caused by direct contact with rear seat passengers, but also cases where front seat occupants received severe injuries due to additional force from rear seat passengers, either impacting directly or indirectly as a result of deformation of the front seat. Severe injuries of front seat occupants were observed in the latter cases. This research validates the importance of seat-belt use for rear seat passengers, not only to protect themselves but also to mitigate injuries of front seat occupants.
Small overlap frontal crashes are defined by a damage pattern with most of the vehicle deformation concentrated outboard of the main longitudinal structures. These crashes are prominent among frontal crashes resulting in serious and fatal injuries, even among vehicles that perform well in regulatory and consumer information crash tests. One of the critical aspects of understanding these crashes is knowing the crash speeds that cause the types of damage associated with serious injuries. Laboratory crash tests were conducted using 12 vehicles in three small overlap test conditions: pole, vehicle-to-vehicle collinear, and vehicle-to-vehicle oblique (15-degree striking angle). Field reconstruction techniques were used to estimate the delta V for each vehicle, and these results were compared with actual delta V values based on vehicle accelerometer data. Estimated delta Vs were 50% lower than actual values. Velocity change estimates for small overlap frontal crashes in databases such as NASS-CDS significantly underestimate actual values.
The improvement of passive car security devices led to a reduction of injuries, especially of the head, the neck and the torso mainly due to the airbag function. The passenger's foot and ankle could not profit from this development. Some investigators even reported a progression of leg injuries (1). In this study, we investigated a current collective of patients with foot and ankle fractures or severe soft tissue injuries in relation with defined crash parameters. Special interest was paid to the car's footwell.
Nowadays airbags are part of the standard equipment in almost all new cars. While airbags are saving an increasing number of people from severe injuries and death in moderate and high speed crashes, they do not completely prevent dashboard injuries. The most common mechanism in dashboard injuries is a posteriorly directed force to the proximal tibia with the knee flexed. This may occur during a motor vehicle frontal impact accident when a knee of the driver or the front-seat passenger strikes the dashboard. The posterior force can be combined with a abducting or rotational force leading to concomitant lateral or posterolateral injury. Car and airbag manufacturers therefore develop special inflatable systems to reduce the impact force in dashboard injuries. Every new inflatable system, however, has to be evaluated in out of position situations in which the system might cause injuries to certain body areas. Therefore, we investigated a new kneebag system in different critical seating positions of post mortem test subjects (PMTS). The tested knee airbag module is a folded airbag (18 litre volume) which is installed below the lower section of the instrument panel of a passenger car. Using four PMTS (2 male, 2 female, age 36"67) the following positions were tested: normal seating position, knee flexed >90 degrees and knee flexed <60 degrees in static deployment tests with direct contact. In addition a dynamic test (48.8kph, AAMA-pulse) was carried out with the PMTS belted in a normal seating position. The inflation phase and the impact of the system on the knee/lower leg were analysed by high speed videos. After the test the lower legs of the PMTS were examined by Xray and autopsy. All soft tissue injuries and bone fractures were recorded. All the tests could be evaluated. Except some superficial skin lesions in the impact area no fracture of the bones around the knee and no knee ligament and tendon injuries were observed. Neither video analysis nor autopsy of the PMTS showed any critical contact injuries caused by the inflation process of the bag. Therefore, it can be concluded that in the tested seating positions which are the most critical for the knee area the knee bag system is safe.
The increase in light duty trucks (LDT) on the road in the US is a safety concern because of their aggressivity, or risk they present to occupants of cars, especially in side impacts. We use FARS data to look at fatality trends in frontal and side impacts between cars and LDT. FARS data is also used to determine risk, or fatalities per registered vehicle, imposed on car drivers from other vehicle types. We use NASS CDS data to investigate sources of serious injuries in vehicles with side impact. These sources of injury are categorized into three major groups: 1) contact without intrusion, 2) contact with intrusion, and 3) restraints. We find a greater fraction of intrusion related injuries in cars struck on their side by SUV or pick-up trucks than when they are struck by other cars.
The National Highways Development Project in India is aimed at upgrading over 12,000 km of national highways from 2-lane undivided roads to 4-lane divided roads. With nearly 40% of fatal crashes being reported on national highways, the effect of this project on road safety needs to be assessed. Researchers carried out on-site crash investigations and in-depth crash data collection for a period of 45 to 60 days on four 2-lane undivided highways and a 4-lane divided highway. Based on 76 crashes examined, researchers found a shift of crash pattern from head-on collisions on undivided 2- lane highways to front-rear collisions on divided 4-lane highways. This paper presents the methodology, analysis of crashes examined, and the critical safety problems identified for greater consideration in future highway development projects. This paper also highlights the need and significance of in-depth crash investigations to understand local traffic conditions and problems in India.
In line with the new definition introduced by the European Commission (EC), the number of seriously injured road casualties in Germany for 2014 is assessed in this study. The number of MAIS3+ casualties is estimated by two different methodological approaches. The first approach is based on data from the German Inâ€Depth Accident Study (GIDAS), which is closely related to the German Road Traffic Accident Statistics. The second approach is based on data from the German TraumaRegister DGU-® (TRâ€DGU), which includes many more hospitals but not all MAIS3+ injuries.
The following paper presents the nature and mechanism of injuries sustained in frontal impacts, focusing on car to car impacts. It was found that the body regions most frequently sustaining severe to fatal injuries were the legs and the thorax. The nature and mechanism of the injury sustained was investigated only for the thorax injuries, due to their potentially life threatening nature. The analysis revealed that the most frequent cause of the injury recorded was the seatbelt for low severity injuries and the front structure of the vehicle for higher severity injuries. An analysis of the effect of load limiter technology in the restraint system showed that the proportion of occupants who sustained "no thorax injury" did not increase when a load limiter was fitted to the restraint system. However, a decrease in the "organ" and "organ and skeletal" injuries was observed in the load limiter sample. Sample size and variation mean that these findings are not conclusive.
Injury probability functions for pedestrians and bicyclists based on real-world accident data
(2017)
The paper is focusing on the modelling of injury severity probabilities, often called as Injury Risk Functions (IRF). These are mathematical functions describing the probability for a defined population and for possible explanatory factors (variables) to sustain a certain injury severity. Injury risk functions are becoming more and more important as basis for the assessment of automotive safety systems. They contribute to the understanding of injury mechanisms, (prospective) evaluation of safety systems and definition of protection criteria or are used within regulation and/or consumer ratings. In all cases, knowledge about the correlation between mechanical behavior and injury severity is needed. IRFs are often based on biomechanical data. This paper is focusing on the derivation of injury probability models from real world accident data of the GIDAS database (German In-depth Accident Study). In contrast to most academic terms there is no explicit term definition or definition of creation processes existing for injury probability models based on empirical data. Different approaches are existing for such kind of models in the field of accident research. There is a need for harmonization in terms of the used methods and data as well as the handling with the existing challenges. These are preparation of the dataset, model assumptions, censored/unknown data, evaluation of model accuracy, definition of dependent and independent variable, and others. In the presented study, several empirical, statistical and phenomenological approaches were analyzed regarding their advantages and disadvantages and also their applicability. Furthermore, the identification of appropriate prediction parameters for the injury severity of pedestrians has been considered. Due to its main effect on injuries of pedestrians and bicyclists, the importance of the secondary impact has also been analyzed. Finally, the model accuracy, evaluated by several criteria, is the rating factor that gives the quality and reliability for application of the resulting models. After the investigation and evaluation of statistical approaches one method was chosen and appropriate prediction variables were examined. Finally, all findings were summarized and injury risk functions for pedestrians in real world accidents were created. Additionally, the paper gives instructions for the interpretation and usage of such functions. The presented results include IRFs for several injury severity levels and age groups. The presented models are based on a high amount of real world accidents and describe very well the injury severity probability of pedestrians and bicyclists in frontal collisions with current vehicles. The functions can serve as basis for the evaluation of effectiveness of systems like Pedestrian-AEB or Bicycle-AEB.