In the context of this study, different data sources for accident research were examined regarding their possible data access and evaluated concerning the individual quality and extent of the data. Analyses of accidents require detailed and comprehensive information in particular concerning vehicle damages, injury patterns and descriptions of the accident sequence. The police documentation supplies the basic accident statistics and is amended in the context of the forensic treatment by further information, e.g. by medical and technical appraisals and witness questionings. As a new approach to the data acquisition for the analysis of fatal traffic accidents, the information was made usable which was collected by the police and by the investigations of the public prosecutor. The best strategy for obtaining reliable, extensive and complete data consists of combining the information from these two sources: the very complete, but elementary statistic data of the Niedersächsisches Landesamt für Statistik (Lower Saxony State Authority of Statistics), based on the police documentation as well as the very extensive accident information resulting from the investigation documentation of the public prosecutor after conclusion of the procedure, the so-called Court Records. Of all 715 fatal traffic accidents, which happened in the year 2003 in the German State of Lower Saxony, 238 cases were selected by means of a statistically coincidental selective procedure based on a statistically representative manner (every third accident). These cases cover the investigation documents of the 11 responsible public prosecutor- offices, which were requested and evaluated while preserving the data security. Of the 238 cases 202 cases were available, which were individually coded and stored in a data base using 160 variables. Thus a data base of a sample of representative data for fatal accidents in Lower Saxony was set up. The data base contains extensive information concerning general accident data (35 variables), concerning road and road surface data (30 variables), concerning vehicle-specific data (68 variables) as well as concerning personal and injury data (27 variables).
From literature well-known analyzes on risks, hazards and causes of accidents of older drivers are amended by the present study in which a comparison of the specific features of accident causes of older car drivers (older than 60 years) and of younger car drivers (under 25 years) is conducted. Mainly the question is pursued if specific errors, mistakes and lapses are predominant in the two different age groups. The analysis system ACAS (Accident Causation Analysis System) used hereby consists of a sequential system of accident causation factors from the human, the technical and the infrastructural field, whereupon for this study the influence of the human features on the accident development in two different age groups is of interest. ACAS is both an accident model and an analysis and classification system, which describes the human participation factors of an accident and their causes in the temporal sequence (from the perceptibility to concrete action errors) taking into consideration the logical sequence of individual basic functions. In five steps (categories) of a logical and temporal sequence the hierarchical system makes human functions and processes as determinants of accident causes identifiable. The methodology specifically focuses on the use in so-called "In-Depth" and "On-Scene" investigation studies. With the help of the system for each accident participant one or more of five hypotheses of human cause factors are formed and then specified by appropriate verification criteria. These hypotheses in turn are further specified by indicators in such manner that the coding of the causation factors by a code system meets the needs of database processing and are accessible to a quantitative data analysis. The first results of the descriptive comparison of the two age groups concern mainly differences in the functional levels "information admission/perception" (where the elderly drivers have more difficulties than the young ones) and "information processing/evaluation" (where the younger drivers show more problems). Concerning the cognitive function of "planning" the group of younger drivers seems to be more often involved in an accident because of excessive speed.
For the avoidance of traffic accidents by means of advanced driver assistance systems the knowledge of failures and deficiencies a few seconds before the crash is of increasing importance. This information e.g. is collected in the German accident survey GIDAS by an interview derived from the ACAS methodology. However to display the whole range of accident causation factors additional information is needed on enduring factors of the system components "human", "infrastructure" and "machine". On the strategic level these accident moderating factors include long term influences such as medical preconditions or a general higher risk taking behavior as well as influences on the immediate conflict level such as an aggressive response to a perceived previous traffic conflict. This study was conducted to examine the feasibility of collecting such causation information in the scope of an in-depth accident investigation like GIDAS. Due to the comprehensive amount of information necessary to estimate the moderating factors the collection of the information is distributed to different methods. 5 cases of real world crashes have been investigated where information was collected on-scene and retrospective by interviews. The identified moderating factors of the accidents and the method for collecting the information are displayed.
Airbags sind ein wichtiger Bestandteil der passiven Sicherheitsausstattung von Fahrzeugen, haben sich in den letzten 30 Jahren stark weiterentwickelt und somit die Schutzwirkung für die Insassen weiter erhöht. Ziel dieser Arbeit ist es, auf Basis verschiedener Datensätze die Schutzwirkung von modernen Airbagsystemen aufzuzeigen und weiteres Opimtierungspotential offenzulegen. Dabei wurde der Fokus auf die Analyse von Realunfalldaten und Verletzungen durch Airbags und deren Schallpegel gesetzt.
Daten aus dem Unfallgeschehen im Straßenverkehr wurden auf Basis von GIDAS- und NASS-Daten ausgewertet. Mittels der ausgewerteten GIDAS-Daten konnte gezeigt werden, dass bei einem Delta-v von ca. 20 km/h bereits 50 % aller Airbags ausgelöst wurden, welches nicht den Erwartungshorizont der Auslöseschwelle von 25 bis 30 km/h nach KLANNER et al. (2004) entspricht. Außerdem wurde ein Trend erkannt, der zeigt, dass bei neueren Fahrzeugen die Anzahl der Airbagzündungen in einem Unfall steigt. Eine statistische Auswertung von airbaginduzierten Verletzungen ergab, dass keine statistisch signifikanten Ergebnisse in Bezug auf airbaginduzierte Verletzungen entnommen werden konnten, allerdings konnten in den analysierten Fällen leichte Verletzungen identifiziert werden, die durch die Airbagzündung verursacht wurden. Die festgestellten Verletzungen waren beispielsweise Schürfwunden, Prellungen und Verbrennungen bis maximal 2. Grades. Es wurden 14 Einzelfälle analysiert bei denen die Verletzungsschwere höher war, als es die Unfallschwere erwarten ließ. Davon waren elf Unfälle durch schlechte strukturelle Interaktion gekennzeichnet, beispielsweise Unterfahren, zentraler Stoß oder Stoß außerhalb der Längsträger. Im vorliegenden GIDAS-Datenmaterial und in der Analyse von MHH Patientinnen- und Patientendaten konnten Einzelfälle, bei denen es zu Hörschädigung in Folge einer Airbagzündung kam, identifiziert werden, allerdings konnte keine statistisch signifikante Verbindung zwischen Airbagzündung und einer Hörschädigung festgestellt werden.
Auf Basis der analysierten GIDAS-Fälle wurde eine Versuchsmatrix entwickelt, um die aufgezeigten Probleme mittels experimenteller Unfallrekonstruktion und akustischer Messungen zu adressieren. In der Unfallrekonstruktion mit zentralem Baumaufprall konnte gezeigt werden, dass bei dem vorliegenden Fall eine frühere Airbagzündung das Brustverletzungsrisiko hätte senken können und somit die vorliegende Brustverletzung wahrscheinlich vermieden hätte. In dem analysierten Auffahrunfall mit einer Unterfahrensituation konnte gezeigt werden, dass die Airbagauslösung unnötig war, da das Verletzungsrisiko durch die Airbagzündung nicht reduziert wurde. In diesem Fall hätte eine unterdrückte Airbagzündung die Hörschädigung des Fahrers verhindert.
Im Rahmen der durchgeführten akustischen Messungen wurden systematische Messungen von Schallpegeln in Fahrzeugen während eines Unfalls und im Stand gemessen. Es konnte gezeigt werden, dass die Crashbegleitgeräusche der Fahrzeugdeformation ausreichen, um den Stapediusreflex auszulösen, dadurch ist das Risiko einer Hörschädigung gering – trotz Pegel von über 160 dB. Das Risiko für eine Hörschädigung steigt mit der Anzahl der gezündeten Airbags durch die kurze Aneinanderreihung von Knallereignissen trotz ausgelösten Stapediusreflex. Auch bei frühen Zündzeitpunkten steigt das Risiko einer Hörschädigung, da der Stapediusreflex noch nicht ausgelöst ist oder sich in der Anschwellphase befindet und somit seine Schutzwirkung nicht komplett entfalten kann.
Mit den analysierten Daten konnte gezeigt werden, dass die Schutzwirkung von Airbags unumstritten ist, allerdings wurde Optimierungspotential in den Zündalgorithmen offengelegt. Das gilt für Unfälle mit schlechter struktureller Interaktion und daraus resultierendem nicht optimalen Zündzeitpunkt und für eine unnötige Airbagauslösung bei geringer Unfallschwere. Weiteres Optimierungspotential zur Reduzierung des Verletzungsrisikos besteht bei Airbags hinsichtlich ihres Potentials Schürfwunden, Prellungen, Verbrennungen und Hörschäden zu verursachen.
Introduction: The method of causation analysis applied under the German accident survey GIDAS, which is based on Accident Causation Analysis System (ACAS) focuses on an on-scene data collection of predominantly directly event-related causation factors which were crucial in the accident emergence as situational resulting events and influences. The paradigm underlying this method refers to the findings of the psychological traffic accident research that most causally relevant features of the system components human, infrastructure and vehicle technology are found directly in the situation shortly before the accident. This justifies the survey method which is conducted directly at the accident (on-scene), shortly after the accident occurrence (in-time) with the detection of human-related causes (in-depth). Human aspects of the situation analysis that interact and influence the risk situations shortly before the collision are reported as errors, lapses, mistakes and failures in ACAS in specific categories and subcategories. Thus methodically ACAS is designed primarily for the collection of accident features on the level of operational action, which certainly leads to valid findings and behavioral causes of accidents. The enhancement by means of Moderating Conditions concerns the pre-crash phase in different levels: strategical, tactical and operational.
Bedingt durch ihre Definition - mindestens 24-stündiger Klinikaufenthalt - umfasst die Kategorie der Schwerverletzten in der amtlichen Verkehrsunfallstatistik eine große Breite tatsächlicher Verletzungsschweregrade. Durch das hohe persönliche Leid sowie die bedeutsamen volkswirtschaftlichen Kosten sind innerhalb dieser Gruppe die Schwerstverletzten von besonderem Interesse. Es werden drei Studien der Bundesanstalt für Straßenwesen (BASt) vorgestellt, in denen auf Grundlage verschiedener Datenquellen Verletzungsmuster und Verletzungsschwere in Zusammenhang mit Parametern des Unfallgeschehens gebracht wurden. Zusammengefasst zeigt sich, dass (a) die Zahl der Schwerstverletzten sich in den letzten Jahren nicht in gleichem Maße reduziert hat, wie die Zahlen Schwerverletzter und Getöteter; (b) sich über verschiedene Datenquellen (GIDAS, TraumaRegister DGU, Rettungsdienst, Polizei) ähnliche Verletzungsmuster in Abhängigkeit der Verkehrsteilnahme zeigen; (c) durch die Verbindung von medizinischen Daten des TraumaRegisters mit Daten der Polizei gute Voraussetzungen für eine umfangreiche Erfassung Schwerstverletzter in Deutschland geschaffen werden könnten.
Within the COST Action TU1101 the working group WG 1 is dealing with acceptance criteria and problems in helmet use while bicycling concerning conspicuity, thermal stress, ventilation deficits and other potential confounding. To analyze the helmet usage practice of bicyclists in Europe a questionnaire was developed in the scope of working group 1 to collect relevant information by means of a field study. The questionnaire consists of some 66 questions covering the fields of personal data of the cyclist, riding und helmet usage habits, information concerning the helmet model and the sensation of the helmet, as well as information on previous bicycle accidents. A second complementary study is conducted to analyze if the use of a bicycle helmet influences the seating geometry and the posture of cyclists when riding a bicycle and if the if the helmet vertically limits the vision. For this purpose cyclists with and without helmets were photographed in real world situations and relevant geometrical values such as the decline of the torso, the head posture of the upper vertical vision limit due to the helmet were established from the photos. The interim results of the field studies which were conducted in Germany by the Hannover Medical School are presented in this study. Some 227 questionnaires were filled out, of which 67 participants had used a helmet and 42 of the 227 participants have had a bicycle accident before. For the analysis of the riding position and posture of the cyclist over 40 pictures of riders with a helmet and over 240 pictures of riders without a helmet were measured concerning the seating geometry to describe the influence of using a bicycle helmet. Some results in summary: From the riders interviewed with the questionnaire only 11% of the city bike riders and 12% of the mountain bike riders always used the helmet, while 38% of the racing bike riders and 88% of the e-bike-riders always used the helmet. The helmet use seems not to change the sensation of safety of cycling compared to the use of a car. The arguments for not wearing a helmet are mostly stated to be the short distance of a trip, high temperatures or carelessness and waste of time. The reasons for using a helmet are stated to be the feeling of safety and being used to using a helmet. Being a role model for others was also stated to be a reason for helmet use. Concerning the sensation of the helmet 9% of the riders reported problems with the field of vision when using a helmet, 57% saw the problem of sweating too much, and 10% reported headaches or other unpleasant symptoms like pressure on the forehead when using the helmet. The analysis of the seating posture from the pictures taken of cyclists revealed that older cyclists generally have a riding position where the handle bar is higher than the seat (0-° to 10-° incline from seat to handlebar), while younger riders had a higher variance (between -10-° decline and 20-° incline). Further, elderly riders and riders with helmets seem to have a more upright position of the upper body when cycling. The vertical vision limit due to the helmet is determined by the front rim of the helmet (mostly the sun shade). Typical values here range from 0-° (horizontal line from the eye to the sun shade) to 75-° upwards, in which elderly riders tend to have a slightly higher vertical vision limit possibly due to the helmet being worn more towards the face.
As the official German catalogue of accident causes has difficulty in matching the increasing demands for detailed psychologically relevant accident causation information, a new system, based on a "7 Steps" model, so called ACASS, for analyzing and collecting causation factors of traffic accidents, was implemented in GIDAS in the year 2008. A hierarchical system was developed, which describes the human causation factors in a chronological sequence (from the perception to concrete action errors), considering the logical sequence of basic human functions when reacting to a request for reaction. With the help of this system the human errors of accident participants can be adequately described, as the causes of each range of basic human functions may be divided into their characteristics (influence criteria) and further into specific indicators of these characteristics (e.g. distraction from inside the vehicle as a characteristic of an observation-error and the operation of devices as an indication for distraction from inside the vehicle. The causation factors accordingly classified can be recorded in an economic way as a number is assigned to each basic function, to each characteristic of that basic function and to each indicator of that characteristic. Thus each causation factor can be explicitly described by means of a code of numbers. In a similar way the causation factors based on the technology of the vehicle and the driving environment, which are also subdivided in an equally hierarchical system, can be tagged with a code. Since the causes of traffic accidents can consist of a variety of factors from different ranges and categories, it is possible to tag each accident participant with several causation factors. This also opens the possibility to not only assign causation factors to the accident causer in the sense of the law, but also to other participants involved in the accident, who may have contributed to the development of the accident. The hierarchical layout of the system and the collection of the causation factors with numerical codes allow for the possibility to code information on accident causes even if the causation factor is not known to its full extent or in full detail, given the possibility to code only those cause factors, which are known. Derived from the systematic of the analysis of human accident causes ("7 steps") and from the practical experiences of on-scene interviews of accident participants, a system was set in place, which offers the possibility to extensively record not only human causation factors in a structured form. Furthermore, the analysis of the human causation factors in such a structured way provides a tool, especially for on-scene accident investigations, to conduct the interview of accident participants effectively and in a structured way.
With an ever rising human life expectancy the share of elderly people in society is constantly rising. This leads to the fact that at the same rate the share of people with age related diseases such as dementia and poor eyesight taking part in traffic will rise and therefore traffic accidents caused by this group of people due to the disease will play an ever greater role. This Situation will be among the future challenges of road safety work. At present this study displays specific characteristics of accidents caused by elderly car drivers (aged 65 or higher) based on the analysis of the German In-Depth Accident Study GIDAS. Herein almost 1000 elderly car drivers were identified as accident participants in the years 2008 to 2011. The focus of this study lies on identifying special types of accidents which are caused by elderly drivers and on characterizing these types with the information gathered on scene and by interviewing the participants. The main evidence analyzed is the knowledge about the accident locality, the trajectories of the participants as well as the reasons for the occurrence of the accidents. Furthermore personal information such as the personal condition before the accident and driving purposes is used to identify patterns of contributing circumstances for accidents caused by elderly traffic participants.
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.