A particular challenge in the development of highly-automated driving functions is the validation of these systems. A possible approach to cope with the validation effort is the use of simulations. Thereby, simulators can be used in various aspects of the validation process. For a meaningful application of simulators, individual aspects of reality are replaced by models. Based on an analysis of the different use cases, the various driver models from the state-of-art will be examined in this article with regard to their conceptual suitability for safeguarding highly automated driving functions.