A method for controlling a motor vehicle includes steps of controlling a longitudinal speed of the motor vehicle to a predetermined value and scanning an upcoming driving route with the aid of a sensor on board the motor vehicle. One end of a section of the driving route which is visible with the aid of the sensor is determined. Assuming that there is an obstacle on the driving route beyond the visible section, it is determined that a deceleration which would be required to maintain a predetermined minimum distance from the assumed obstacle exceeds a predetermined threshold value, and a signal is output to a driver of the motor vehicle.