A multidisciplinary Road Accident Analysis Group with the objective of conducting in-depth investigations of specific types of accidents has existed in Denmark for some years. The group has analysed head-on collisions, left-turn accidents, truck accidents and single vehicle accidents. The data collection included police reports, the group's investigation of accident sites and vehicles involved, and interviews with the involved road users and witnesses. The main accident factors in the head-on collisions and in the single vehicle accidents were excessive speed, drunk driving and driving under the influence of illegal drugs. The primary accident factors in left-turn accidents were attention errors or misjudging the amount of time available to complete the left turn. In the truck accidents insufficient searching for visual information as well as speeding were major factors. For all the accident themes the primary injury factor was failure to wear seat-belts. The multidisciplinary approach has provided a rather precise knowledge of the contributing factors leading up to the accident. The method requires a lot of resources, which is a limiting factor for the number of accidents to be analysed in this way. However, the method is suitable for analysis of common occurring or very serious types of accidents. (C) 2004 Elsevier B.V. All rights reserved.