Method for operating a longitudinally guiding driver assistance system and motor vehicle

The method involves controlling speed of a motor car (1) depending on control data, and providing curve data as the control data and as nearest curve data describing a drive curve during control of the motor car. The curve data is determined from road course data of a navigation device, and environment data is determined by a foresighted environment sensor. Comfort curve rate is determined by the consideration of the curve data. The comfort curve rate is determined from maximum curvature of a curve at a defined location and a predefined comfort lateral acceleration. An independent claim is also included for a motor car.