In the framework of the development of the European road accident data base with disaggregate data, CARE, the CAREPLUS 2 project aims to produce methods for the support of reliable and useful analysis of road accident data contained inside CARE.  This project will face a series of incompatibilities and will propose valid solutions.  CAREPLUS 2 project will produce three types of results: a full glossary of national values and variables used, transformation rules for the comparable national values and the common contents for the European data base.