A driver assistance system for motor vehicles has a sensor device for measuring data about the environment of the vehicle, at least two assistance functions, and a data processing device, which analyzes the measured data and generates at least one specific environmental hypothesis for each assistance function, which provides output data in a form prepared for the corresponding assistance function, at least one environmental hypothesis which has a structure divided into a plurality of partial hypotheses being predefined in the data processing device, and the partial hypotheses having such a logical relationship with one another that output data of one partial hypothesis flow into the generation of the other partial hypothesis, and at least two assistance functions directly or indirectly use a shared partial hypothesis.