Navigation device for land vehicles

The proposal is for a navigation device for road vehicles, especially passenger cars and lorries, having a store for geographical data, sensors to detect current running data, a comparator device and an information issuing device. The navigation device is characterized in that the safe boundary speed (vi) for travelling the stretch is determined in a computing unit (9) from the geographical data on the cycle of that stretch of journey and compared with the actual speed of the vehicle. If the boundary speed is exceeded or not reached, an information issuing device (11) is activated and, where appropriate, a converter device (13) which act on vehicle controls, e.g. brake or engine control.