Evaluating the causes of traffic accidents due to human factors with ACAS

For the multivariate requirements of in-depth studies on accident causes a methodology (ACAS - Accident Causation Analysis System) was developed at the Medical School Hannover, Germany, which is to aid the on-scene accident research GIDAS (German In-depth Accident Study) and which is in use since the beginning of 2008. In a study conducted for the Federal Highway Research Institute (BASt), Germany, suggestions were made, based on a bibliographical evaluation and different method variations, which accommodate both research based on an analysis of the accident participant as well as the conditions of an accident research working on-scene. Apart from the collection of technical and infrastructural characteristics the analysis of the human influences during the accident development contributes to the explanation of causes. Therefore, the influence of the situational effective behaviour is recorded in the context of an analysis of the persons involved as soon as possible after the accident and if possible at the site of the accident. The explorative analysis of accident causes in seven steps based on traffic-psychology considers the dynamic process character of human functions, which play a role in the avoidance of collisions when coping with a traffic conflict. The 5 categories of the human cause factors are an analysis and order system, which describes the possible human causation factors at the moment of the accident development from perceptibility to action errors. These categories are first based on error tracing in the top category of the "information access" and subsequently on the basic 4 human functions (from "observing" to "operating"), which run in chronological order from recognizing the danger up to the reaction to a cause, e.g. a traffic situation evaluated as critical. Based on this structure, the human cause factors can be divided not only into meaningful categories, but can be recognized and collected more easily because of a structured questioning method. As process model "ACAS" takes into account the dynamic sequences which develop, if a human with his characteristics, abilities and restrictions intervenes in a system. The core method of interviewing the persons involved created a structure of the procedure of data acquisition. The identification of causes of accidents in human behaviour should consider the process character of human observation, thinking and acting, in order to arrive at manageable analysis units, which permit clear statements as to the respective human sources of error on distinguishable "functional levels". A procedure based on hypotheses lends itself for this purpose, where for every step within the processing concept of the seven steps a core hypothesis is presented, which can be disproved using certain criteria. The respective criterion again experiences its validity of the allocation by different indicators, which are collected at the site of the accident in a predominantly explorative manner. The methodology of the collection of accident causes was presented for the first time at the first international conference "Expert symposium on Accident Research" (ESAR) in September 2004. After a testing phase it has been used in this shape by GIDAS in the course of the ongoing analyses of accidents at the medical university Hanover. The model it is based on has been theoretically justified and its implications for application on the special conditions of an "in-depth/on the spot" analysis were derived. Within two years of developing work, the model underwent a definition and an adjustment taking into account the feasibility and restrictions of the research at the sites of accidents, where the aspect of the "feasibility" and the realistically executable time and effort for data acquisition and coding was focused on. A further objective was as high an agreement of the model structure with the collection instruments derived from it as possible and their adjustment to the half-standardized interview form used up to that time. (A)


  • English

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 43-5
  • Monograph Title: Fit to drive. Proceedings of the 8th International traffic expert congress. Warsaw, May 8th-9th 2014
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 01597264
  • Record Type: Publication
  • Source Agency: Bundesanstalt für Straßenwesen (BASt)
  • ISBN: 978-3-2812-1918-2
  • Files: ITRD
  • Created Date: Mar 22 2016 3:15AM