The project will conduct a pilot study to investigate how data in STRADA (Swedish Traffic Accident Data Acquisition) and Trafikverkets Dödsolycksdatabas can be used to develop a national in-depth database for traffic accidents. The plan is for the in-depth studies to cover not only fatal accidents but also serious injuries (AIS2 +). This will create opportunities for better follow-up of the traffic safety situation in Sweden. A method for using where existing data sources will be combined makes it possible to get a more detailed description of traffic accidents. The project will also investigate what data is missing and needs to be collected in future accident investigations. The data format that will be developed will be designed to be able to make comparisons with existing European and global accident databases.