This study has been performed by VTI for the Swedish Road Traffic Inspectorate. The aim was to collect data which will make it possible to describe, analyse and try to explain the changes in the number killed in traffic over the period 1996-2005. Previously it was possible to observe long term changes on the basis of a breakdown by state/ municipal road management authorities and a breakdown by accident type. This was no longer possible after the introduction of a new accident data system in 2003. In this project, an alternative breakdown and description of the development in the number killed is proposed. For each individual year (1996-2005) a "collision matrix" is constructed. This matrix shows which road user categories have been killed and whether this has occurred without a collision (single vehicle accident) or in collision with some other traffic element. Breakdowns by "urban/rural", sex and age group are also made in the matrix. Both the assessment of the police and the definition of urban areas by Statistics Sweden SCB have been used as regards the urban/rural breakdown. The breakdown urban/rural is a substitute for municipal/state road management authority, and the breakdown non-collision/collision is a substitute for accident type.