There is a need to estimate impacts of proposed driver assistance systems already at early stages of the system development process. Estimations of the impacts of new technologies have to be based on laboratory studies and modelling. This paper presents a traffic simulation based framework for estimation of the traffic system wide impacts of driver assistance systems. The framework includes a two-step methodology. In the first step of the analysis, the considered driver assistance system’s impact on driver behaviour is observed. The second step of the analysis consist of traffic simulation modelling taking into account the system functionality as well as the observed driver behaviour of the considered driver assistance system. Driver behaviour studies for use of the data for traffic simulation modelling is discussed and traffic simulation modelling of different types of driver assistance systems is exemplified by modelling of an overtaking assistant, of in-vehicle virtual rumble strips and of adaptive cruise control.