80 Unfallforschung
In Germany, in-depth accident investigations are carried out in the Hannover area since 1973. In 1999 a second region was added with surveys in Dresden and the surrounding area. Internationally, the acronym GIDAS (German In-Depth Accident Study) is commonly used for these surveys. Compared to many other countries, the sample sizes of the GIDAS surveys are much larger. The goal is to collect 1.000 accidents involving personal injuries per year and region. Data collection takes place by using a sampling procedure, which can be interpreted as a two-stage process with time intervals as primary units and accidents as secondary units. An important question is, to what extend these samples are representative for the target population from which they are drawn. Analyses show, for example, that accidents with persons killed or seriously injured are overrepresented in the samples compared to accidents with slightly injured persons. This means, that these data are subject to biases due to uncontrolled variation of sample inclusion probability. Therefore, appropriate weighting and expansion methods have to be applied in order to adjust or correct for these biases. The contribution describes the statistical and methodological principles underlying the GIDAS surveys with respect to sampling procedure, data collection and expansion. In addition, some suggestions regarding potential improvements of study design are made from a methodological point of view.
The second ESAR Conference took place at the Medical University Hannover. This year conference presents the current state of affairs of relevant research activities in the field of in-depth investigations. The first conference on ESAR (Expert Symposium on Accident Research) was established in 2004. It is planned to hold ESAR every two years. Hannover seems to be the right place for this conference concerning the fact that the first in-depth research team was found here in the year 1973 and comprehensive studies on accident analysis were spread out from here around the world continuously. This year conference topped all expectations in terms of the numbers of participants, in the variety of papers and the interdisciplinary of presenters from medical, psychological and engineering background. More than 100 delegates from all over the world, that means 13 different countries and from 4 different continents, came to Hannover, presented their results of accident investigation and discussed countermeasures for accident prevention and injury reduction. ESAR should be a platform for exchange of knowledge to find an optimized way for increase of traffic and vehicle safety by in-depth investigation and methodology. ESAR as international conference should be a platform for consideration of all nations round the world. This seems to be very important for the current situation, having high safety in the high industrial countries of Europe, US and Australia, but low safety and high injury risk in Asia and Africa.