A driving assistance system for regulating an operation of a vehicle in a discrete manner according to different ranges of risk potentials associated with the vehicle, such that different risk potentials in different ranges are conveyed to the driver in a different and discrete manner. The system includes a device for calculating a risk potential associated with the vehicle, and a data processor for regulating an operation of the vehicle, such as a reaction force applied to the acceleration pedal, based on a control parameter assuming one of a plurality of values according to the calculated risk potential associated with the vehicle, wherein each of the values is assigned to one of a plurality of predetermined ranges of risk potentials.