A method for situation analysis for a driver assistance system on board a motor vehicle comprises steps of provision of a representation of surroundings of the motor vehicle, wherein the representation comprises an arrangement of cells that are reversibly explicitly associated with predetermined sections of the surroundings, of scanning of surroundings of the motor vehicle by means of at least one sensor in order to sense an obstacle, and of marking cells on the basis of the scan such that a cell that is associated with an obstacle-free section of the surroundings carries a first marker and a cell that is associated with a section of the surroundings in which an obstacle has been sensed carries a second marker. A morphological filter is then applied to the representation in order to provide cells that cannot be reached by the motor vehicle with the second marker.