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In most of developed countries, the progress made in passive safety during the last three decades allowed to drastically reduce the number of killed and severely injured especially for occupants of passenger cars. This reduction is mainly observed for frontal impacts for which the AIS3+ injuries has been reduced about 52% for drivers and 38% for front passengers. The stiffening of the cars' structure coupled with the generalization of airbags and the improvement of the seatbelt restraint (load limiter, pretension, etc.) allowed to protect vital body regions such as head, neck and thorax. However, the abdomen did not take advantage with so much success of this progress. The objective of this study is to draw up an inventory on the abdominal injuries of the belted car occupants involved in frontal impact, to present adapted counter-measures and to assess their potential effectiveness. In the first part the stakes corresponding to the abdominal injuries will be defined according to types of impact, seat location, occupants' age and type of injured organs. Then, we shall focus on the abdominal injury risk curves for adults involved in frontal impact and on the comparisons of the average risks according to the seat location. In the second part we will list counter-measures and we shall calculate their effectiveness. The method of case control will be used in order to estimate odds ratio, comparing two samples, given by occupants having or not having the studied safety system. For this study, two type of data sources are used: national road injured accident census and retrospective in-depth accident data collection. Abdominal injuries are mainly observed in frontal impact (52%). Fatal or severe abdominal occupant- injuries are observed at least in 27% of cases, ranking this body region as the most injured just after the thorax (51%). In spite of a twice lower occupation rate in the back seats compared to the front seats, the number of persons sustaining abdominal injuries at the rear place is higher than in the front place. In recent cars, the risk of having a serious or fatal abdominal injury in a frontal impact is 1.6% for the driver, 3.6% for the front passenger and 6.3% for the rear occupants. The most frequently hurt organs are the small intestine (17%), the spleen (16%) and the liver (13%). The most common countermeasures have a good efficiency in the reduction of the abdominal injuries for the adults: the stiffness of the structure of the seats allows decreasing the abdominal injury risk from 54% (driver) to 60% (front occupant), the seatbelt pretensioners decrease also this risk from 90% (driver) to 83% (front passenger).
Detailed anthropometric data of pregnant women have been collected and used in the development of a computational model of the pregnant occupant model "Expecting". The model is complete with a finite element uterus and multi-body fetus, which is a novel feature in the models of this kind. The computational pregnant occupant model has been validated and used to simulate a range of impacts. The strains developed in the utero-placental interface are used as the main criteria for fetus safety. Stress distributions due to inertial loading of the fetus on the utero-placental interface play a role on the strain levels. Inclusion of fetus model is shown to significantly affect the strain levels in the utero-placental interface. This series of studies has led to the design of seatbelt features specifically for the pregnant women to enable them use the seatbelt correctly and comfortably.
The use of proper child restraint systems (CRS) is mandatory for children travelling in cars in most countries of the world. The analysis of the quantity of restrained children shows that more than 90% of the children in Germany are restrained. Looking at the quality of the protection, a large discrepancy between restrained and well protected children can be seen. Two out of three children in Germany are not properly restrained. In addition, considerable difference exists with respect to the technical performance of CRS. For that reason investigations and optimisations on two different topics are necessary: The technical improvement of CRS and the ease of use of CRS. Consideration of the knowledge gained by the comparison of different CRS in crash tests would lead to some improvements of the CRS. But improvement of child safety is not only a technical issue. People should use CRS in the correct way. Misuse and incorrect handling could lead to less safety than correct usage of a poor CRS. For that reason new technical issues are necessary to improve the child safety AND the ease of use. Only the combination of both parts can significantly increase child safety. For the assessment of the safety level of common CRS, frontal and lateral sled tests simulating different severity levels were conducted comparing pairs of CRS which were felt to be good and CRS which were felt to be poor. The safety of some CRS is currently at a high level. All well known products were not damaged in the performed tests. The performance of non-branded CRS was mostly worse than that of the well known products. Although the branded child restraint systems already show a high safety level it is still possible to further improve their technical performance as demonstrated with a baby shell and a harness type CRS.
Safety of light goods vehicles - findings from the German joint project of BASt, DEKRA, UDV and VDA
(2011)
Light goods vehicles (LGVs) are an important part of the vehicle fleet, providing a vital component in the European transportation system. On the other hand, LGVs are in the focus of public discussion regarding road safety. In order to analyse the accident situation of LGVs in an objective manner, Federal Highway Research Institute (BASt), VDA, DEKRA and German Insurers Accident Research (UDV) launched a joint project. The aim of this project, which will be finished by mid of 2011, is to identify reasonable measures which will further improve the safety of LGVs. For the first time, these partners jointly together conducted a research project and put together their know-how in accident research. Analyses are based on real-life accident data from the GIDAS database, the Accident Database of UDV (UDB), the DEKRA database and national statistics. The findings deliver answers to questions within the arena of future legislative actions and consumer protection activities. The analyses of databases cover areas of primary and secondary safety of LGVs with a special focus on advanced driver assistance systems (ADAS), driver behaviour as well as partner and occupant protection. Key figures from national statistics are used to highlight hotspots of accidents of LGVs in Germany. Finally, the proposed countermeasures are assessed regarding their potential effectiveness. Amongst others, the results show that the accident situation of LGVs is very similar to that of passenger cars. Noteworthy variations could be found in collisions with pedestrians, at reversing and regarding accident causes. Occupant safety of LGVs is on a higher level compared to cars. Results indicate that seatbelt use is on a significantly lower level compared to cars. This leads to higher-than-average injury risk for unbelted LGV occupants. When it comes to partner protection, there are problems with compatibility at LGVs. For car occupants there is a very high injury risk when colliding with a LGV. It indicates that higher passive safety test standards for LGVs would be counterproductive if they further increase stiffness of LGVs. The analysis of LGV-pedestrian accidents shows that pedestrian kinematic differs significantly from car-pedestrian accidents. At this point, existing pedestrian related test standards developed for cars cannot be adopted to LGVs. When it comes to active safety, ESC proved its effectiveness once again. Beyond that, rear view cameras, advanced emergency braking systems and lane departure warning systems show a safety potential, too. In addition to any technical countermeasures previously discussed, the importance of the driver behavior and attitude regarding the accident risk was investigated. In order to develop successful actions it is important to understand the main target population. In the case of LGV especially the crafts business and smaller companies are the major contributors the safety issue.
Providing effective occupant protection in rollover crashes requires supplying the occupant with a restraint system proven effective in the dynamic rollover accident mode. Preventing ejection and providing restraint sufficient to prevent potentially injurious contacts with both interior and exterior vehicle components is paramount for effective rollover occupant protection. Research has shown that the injury potential can be decreased by closely coupling the occupant to the seat. This paper focuses on the effect of restraint system slack and its relationship to occupant excursion and ejection potential during rollover. Various restraint system configurations are evaluated in rollover-type test environments. A review of prior research is presented prior to presenting new quasi-static vehicle inversion studies conducted with live surrogate occupants. Additionally, dynamic rollover testing utilizing anthropometric test devices (ATDs) is presented. The influence of belt looseness and effects of various restraint designs on the belted occupants' injury potential are discussed.
Although the statistics show a decreasing rate of child injuries and fatalities in German road accidents more efforts can be made to protect children in cars e.g. by developing appropriate child restraint systems. An important part in of this work can be achieved with the help of crash tests using child dummies. However these crash tests cannot completely reflect the situation of real world crashes as factors like children moving out of the optimal position or children incorrectly fastened by their parents are difficult to predict. Therefore this study gives an overview over the current accident and injury situation of child occupants in cars in German road accidents.
Who doesn't wear seat belts?
(2009)
Using real world accident data, seat belts were estimated to be 61% effective at preventing fatalities, and 32% effective at preventing serious injuries. They were most effective for drivers with an airbag. Seat belts were estimated as having prevented 57,000 fatalities and 213,000 seriously injured casualties in the UK since 1983. Seat belt legislation was estimated to have prevented 31,000 fatalities and 118,000 seriously injured casualties. A future increase in effective seat belt wearing rate (which takes into account seating position) in the UK from 92.5% to 93% may prevent casualties valued at a societal cost of over -£18 million per year. To target a seat belt campaign, the question "who doesn"t wear seat belts?" must be answered. Seat belt wearing rates and the number of unbelted casualties were analysed. It was primarily young adult males who didn"t wear seat belts, and they made up the majority of unbelted fatalities and seriously injured casualties.
In a first step, we have examined approximately 23 000 single vehicle accidents within the Austrian National Statistics database. In a second step, we considered 15% of all fatal "running off the road" accidents that occurred in Austria in 2003. As a result, two accident categories were specified; "leaving the road without preceding manoeuvre" and "leaving the road with preceding manoeuvre". These two categories can be basically characterised by the vehicle- heading angle and its velocity angle. In this report, we further suggest theoretical approaches for the dimensioning of a safety zone, an area adjacent to the road free of fixed objects or dangerous slopes. We also show the link between the two accident categories mentioned above and the real world accidents analysed in detail. These observations also form the basis for the required length for safety devices. Finally, we summarise accident avoidance strategies.
This study aims to analyze spine injuries in motor vehicle accidents. Between 1985 and 2004 the Hannover accident research unit documented 18353 accidents. We identified 161 front passengers (0.53%) with cervical spine injuries, 84 (0.28%) with thoracic and 95 (0.31%) with lumbar injuries. Technical and medical data was reviewed. Patients" records were retrieved. X-rays were evaluated and fractures were classified according to the Magerl classification. 68% and 57% of thoracic and lumbar fractures occurred in accidents with multiple impacts. Delta-v was 50, 40 and 40 kph in passengers with cervical, thoracic and lumbar spine, resp. Passengers with spinal fractures frequently showed numerous concomitant injuries, e.g. additional vertebral fractures. The influence of seat belts and airbags is discussed. Patient work-up has to include a thorough investigation for additional 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.