Abstract—In order to significantly reduce the amount of testing required to validate the behavior of vehicle safety functions with real vehicles, the scenarios in the simulation must reproduce the traffic as realistically as possible. For this reason, a microscopic traffic flow simulation is used. Since the road users show a perfect behavior by default, driving errors have to be induced. The necessary adjustments in the existing driver models are presented schematically in this paper. These changes in the driving behavior ensure that some road users cause situations that are critical for others. Such scenarios are required as input data for testing vehicle safety functions in a vehicle dynamics simulation. A decisive factor for the quality with which a critical situation can be successfully managed by a vehicle safety function is the trigger time. For this purpose, approaches are presented for estimating the period in which a collision can still be avoided by braking or evasive maneuver. Three intersection scenarios illustrate the functioning of these criteria.