Implementation of ACASS (accident causation analysis with seven steps) in in-depth accident study GIDAS

As the official German database 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 the year 2008. A hierarchical system was developed, which describes the human causation factors in a chronological sequence 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. 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.