Do we learn more from situation based accident coding? Case study of Malmö and Gothenburg

Abstract: Road traffic accidents in Sweden are today registered in the national database called STRADA (Swedish Traffic Accident Data Acquisition). To every accident information is gathered, but an efficient way of compiling this information is lacking. In countries like Germany or Denmark accidents are classified by the type of manoeuvre that leads to the accident. With help from reference tables, every movement possible for a part involved in an accident is given a code, and searches are possible based on accident type. There is also a European accident database, CARE, where accidents are registered based on CADaS structure. By building up a code system and then analyse serious and fatal accidents in Gothenburg and Malmö (2nd and 3rd biggest cities in Sweden) between 2009 and 2013, traffic accidents could be studied in a different way than before. The conclusion is that accident classification similar to CADaS gives another view of the safety problems. Much of the information can only be found in the accident sketch and makes it important to identify the contributing factors. Since a majority of the accidents are single accidents hospital data contribute a lot to understanding the extent of the safety problems, but not as much to understanding the conditions of the accidents. However, going into too much disaggregation quickly results in very few accidents per type and becomes meaningless.