Slovenian data on road traffic accidents and the protection of personal data

In Slovenia the main database on road traffic accidents is maintained by the Ministry of Interior but other related data are also available from the insurance association and the health system. By combining data from different systems one can acquire additional information on road accidents and those participating in them. Through such a process it would be possible to gain some feedback on the quality of the available data. Also, the size of the under-reporting to the police could be estimated and corrected. And, last but not least, the data on the severity of the injuries of participants which is now decided on (for the main database) by the police could be improved (duration of hospitalisation etc). The Act on the Protection of Personal Data from 2004 significantly limits such a merger of databases and rightly so. Nevertheless, we believe that the present situation can be improved. The best possibility seems to be merging of data from different systems under strict public control, de-individualisation (deleting identifying parts) of the merged data and as such made available to the research community for analysis. In the paper we present some results that are based on the probabilistic merging of data from different systems (as second-best possibility) in a form that makes identification of a person impossible (e.g. birth date in the form mm.yyyy).