91 Fahrzeugkonstruktion
Within the process of integrating passenger airbags in the vehicle fleet a problem of compatibility between the passenger airbag and rear-facing child restraint systems was recognised. Especially in the US several accidents with children killed by the passenger airbag were recorded. Taking into account these accidents the deactivation of a present passenger airbag is mandatory if a child is carried in a rear-facing child restraint system at the front passenger seat in all member states of the European Union. This rule is in force since the deadline of 2003/20/EC at the latest. In the past a passenger airbag either could not be disabled or could only be disabled by a garage. Today there are a lot of different possibilities for the car driver himself to disable the airbag. Solutions like an on/off-switch or the automatic detection of a child restraint system are mentioned as an example. Taking into account the need for the deactivation of front passenger airbags two types of misuse can occur: transportation of an infant while the airbag is (still) enabled and transportation of an adult, while the airbag is disabled, respectively. Within a research project funded by BASt both options of misuse were analysed utilising two different types of surveys amongst users (field observations and interviews, Internet-questionnaires). In addition both analysis of accident data and crash tests for an updated assessment of the injury risk caused by the front passenger airbag were conducted. Both surveys indicate a low risk of misuse. Most of the misuse cases were observed in older cars, which offer no easy way to disable the airbag. For systems, which detect a child seat automatically, no misuse could be found. The majority of misuses in cars equipped with a manual switch were caused by reasons of oblivion. Also the accident analysis indicates a minor risk of misuse. From more than 300 cases of the GIDAS accident sample that were analysed, only 24 children were using the front passenger seat in cars equipped with a front passenger airbag. In most of these cases the airbag was deactivated. When misuse occurred the injury severity was low. However, when analysing German single accidents the fatality risk caused by the front passenger airbag became obvious. From the technical point of view, there were important changes in the design of passenger airbags in recent years. Not only volume and shape were modified, but also the mounting position of the entire airbag module was changed fundamentally. Even if these findings do not allow obtaining general conclusions, a clear tendency of less danger by airbags could be identified. For future vehicle development a safe combination of airbags and rear faced baby seats seems to be possible in the long term. This would mean that both types of misuse could be eliminated. For parents an easier use of child seat and car would be the result.
Mit dem Seminar SILENCE wurde ein Forschungsprojekt abgeschlossen, das aus zehn Unterprojekten bestand, und an dem 46 internationale Partner beteiligt waren. Ziel des Projektes war es, die Belästigung durch Verkehrslärm in Ballungsräumen zu reduzieren. Das Projekt wurde in den Jahren 2005 bis 2008 mit insgesamt rund 9 Millionen Euro durch die Europäische Union gefördert. Auf dem SILENCE-Seminar im Mai 2008 in den Räumen der Bundesanstalt für Straßenwesen wurden die aktuellen Forschungsergebnisse von Vertretern der verschiedenen beteiligten Disziplinen präsentiert und diskutiert mit dem Ziel, die gefundenen Problemlösungen an die Anwender zu übermitteln
The Traffic Accident Research Institute at University of Technology Dresden investigates about 1,000 accidents annually in the area around and in Dresden. These datasets have been summarized and evaluated in the GIDAS (German Accident In-Depth Study) project for 13 years. During the project it became apparent that the specific traffic situation of a covert exit of a passenger car and an intersecting two-wheeler involves a high risk potential. This critical situation develops in a large part due to the lack of visibility between the driver and the intersecting bike. In this paper the accident avoidance potential of front camera systems with lateral field of view, which allows the driver to have an indirect sight into the crossing street area will be presented.
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.
This study aimed at developing an injury estimation algorithm for AACN technologies for Germany and compared them to findings based on Japanese data. The data to build and to verify the algorithm was obtained from the German in-depth Accident Database (GIDAS) and split into a training and a validation dataset. Significant input variables and the generalized linear regression model to predict severe injuries (ISS>15) were selected to maximize area under the receiver operating characteristic curve (AUC). Probit regression with the input parameter multiple impact, delta v, seatbelt use and impact direction gave the largest AUC of 0.91. Sensitivity of the algorithm was validated at 90% and specificity at 76% for an injury risk threshold of 2%. It appears that no major differences between Japan and Germany exist for injury estimation based on delta v and impact direction. However, far side impact and multiple crash events appear to be associated with a larger risk increase in the German data.
Institute for Traffic Accident Research and Data Analysis <Tokyo>rnAbstract: Analyses were conducted to clarify the features of rear-end collisions, using an integrated accident database developed by the Institute for Traffic Accident Research and Data Analysis (ITARDA). Focusing on neck injuries in rear-end collisions, analyses were made of the relation to struck-vehicle properties. Regarding the relation to the initial year of registration, the results did not show that newer vehicles tended to have a lower no-neck-injury rate, which was defined in this study as an index. On the contrary, in some passenger car classes, it was observed that the no-neck-injury rate was higher in newer vehicles. The effect of an active head restraint system, which is one type of anti-whiplash device, was analyzed by using not only the no-neck-injury rate but also a regression analysis. The results showed that the effect of an active head restraint system on suppressing the incidence of neck injuries was statistically significant.rn
The share of high-tensile steel in car bodies has increased over the last years. While occupant safety has generally benefited from this measure, there is a potential risk that, as a result, rescue time may increase considerably. In more than 60% of all car occupant fatalities a technical rescue has been necessary. These are in particular those cases where occupants die immediately at the accident scene. Therefore, in these cases "rescue time" is a very sensitive parameter. In addition to the general analysis of the need of technical rescue and the actual rescue time depending on model years, the injury pattern of occupants requiring technical rescue will be analysed to provide advice for rescue teams. Furthermore, a detailed analysis of rescue measures for the most popular car models depending on the safety cell design is given.
This work describes the results of the experimental activity, illustrating the driving behavior observed in different conditions, relating them to the different methods of ADAS intervention and comparing the driver behavior without ADAS. In the present study, driver behavior was studied in road accidents involving elderly pedestrians, with different ADAS HMIs, as a base to develop a driver model in near missing pedestrian accidents. A literature research was conducted with the aim of finding out the main influencing factors, including environment, boundary conditions, configuration of impact, pedestrian and driver information, when pedestrian fatalities occur and an analysis of frequent road accidents was conducted to get more detailed information about the driver- behavior. In order to obtain more detailed information about pedestrian accidents, real road accidents were reconstructed with multibody simulations on PC-Crash and, by the comparison between literature findings and reconstructions, a generic accident scenario was defined. The generic accident scenario was implemented on the full scale dynamic driving simulator in use at the Laboratory for Safety and Traffic Accident Analysis (LaSIS, University of Florence, Italy) in order to analyse the driving behaviors of volunteers, also considering the influence of ADAS devices. Forty-five young volunteers were enrolled for this study, resulting in forty valid tests on different testing scenarios. Two different scenarios consisted in driving with or without ADAS in the vehicle. Different kinds of ADAS, acoustic and optical, with different time of intervention were tested in order to study the different reactions of the driver. The tests showed some interesting differences between driver's behavior when approaching the critical situation. Drivers with ADAS reacted earlier, but more slowly, depending also on the type of alarm, and often with double reaction when braking. In fact, the results of the activity showed that with ADAS intervention the time to collision (TTC) increases, but the reaction time and braking modality change: a) there is a sort of "latency" time between the accelerator pedal release and the brake pressure; b) the brake pressure is initially less intense. So the driver only partially takes advance from the TTC increase. These differences were valued not only qualitatively, but quantitatively as well. This work revealed to be useful to improve the knowledge of drivers" behavior, in order to realize a driver model that can be implemented to help attaining and assessing higher levels of automation through new technology.
Bus or heavy vehicle passenger accidents are rare events, compared with car accidents, but sometimes leads to a large number of victims especially in rollover crash scenarios. Two accidents occurred in Portugal in 2007 and 2013 in which 28 people died and more than 50 are injured, shown the importance of the investigation of such accidents. For the investigation of these accidents multidisciplinary teams are constituted with engineers and police officers. All the factors involved are taken into consideration including road design, traffic signs, maintenance and hardware, human factors, and vehicle factors. In this work a methodology to an accurate collection of the data is proposed. From the information collected the accident is reconstructed using the PC-CrashTM software. From this all the contribution factors are determined and recommendations to mitigate these crashes are listed. These two accidents are rollover accidents and the analysis of the injuries and its correlation with the use of retention systems is very important. From the medical data and with the dynamics of the accident determined simulations of the occupants with biomechanical models are carried out in order to evaluate the effect of the retention systems in the injuries. This analysis is based on injury criteria (such as Abbreviated Injury Score (AIS) or Injury Severity Scale (ISS)). With this it is possible to determine if the seat belt was worn or not.
In-depth road traffic accident research in Spain is a fairly recent activity. In the past, only accident data that had been retrospectively processed by the national and regional traffic police forces was available. In 1999 Applus+IDIADA set up a permanent accident research unit to carry out indepth analysis of road accidents in Spain. Since then accidents involving cars, motorcycles, coaches and vulnerable road users have been thoroughly studied. The Applus+IDIADA accident research team has carried out work for the various traffic polices in Spain and it is currently involved in several research projects in which accidentology is one of the main tasks. The working methodology of the team is presented in the first part of the paper. In the framework of the European research project "Rollover" (GRD2-2001-50086), Applus+IDIADA has collected data, inspected scenarios and performed virtual reconstructions of twenty-six of the total seventy-six rollover accidents studied. The second half of the paper describes how these accident investigations were used to develop a test procedure for identifying possible improvements to the vehicle structure which augment occupant protection in a rollover scenario. In particular, a proposal for a new drop test for rollover assessment is presented. The cases were analysed for severity, in terms of injury to the occupants and damage to the vehicle, and taking into account whether a seatbelt was worn or not. The worst possible cases were identified as those that had severe occupant injuries and sizable damage to the occupant compartment when seatbelts had been worn. The most severe cases were then analysed further for impact position (roll and pitch angles) and the impact velocity. With these parameters taken into account, the most representative combinations could be found. This resulted in a series of configurations for possible drop tests. The results of the tests indicate where passenger vehicle structures need to be improved in order to increase occupant safety in the event of a rollover crash.