This paper presents a model-based approach to road traffic safety developed within the EU funded project IN-SAFETY. Several existing models, both micro- and macro-models, will be adapted and used to assess safety related effects of ITS measures. Examples of such measures include but are not limited to ADAS and IVIS. While the micro-models will determine the individual vehicles’ safety related behaviour, the macro-models will find out about the network wide aspects. Various models will be extended to cope with the ITS measures envisaged and then applied to relevant safety critical conditions. Major input will be available from the different test sites of the project, which are spread to cover the most significant aspects within the EU road environment.