Method for operating a sideways driver assistance system of a motor vehicle and motor vehicle

The method involves determining a future road course from environment and/or operating data. A transverse guiding parameter determining a steering intervention is derived from the course. A road vertical exaggeration information (21) describing change of deviation of a transverse course of a road surface from a horizontal, is considered during determination of the road course and/or the guiding parameter. A lateral track deviation resulted from change of a road vertical exaggeration, is determined by considering the information. The guiding parameter is corrected by adaptation.