Driving assist system and method for vehicle

A vehicle driving assist system comprises a travel situation detection means (10, 20, 40) for detecting a vehicle condition and a traveling environment around a subject vehicle; a risk potential calculation means (52) for calculating a risk potential around the subject vehicle based upon detection results of the traveling situation detection means (10, 20, 40); an accelerator pedal reaction force calculation means (53) for calculating an accelerator pedal reaction force command value based upon the risk potential which is calculated by the risk potential calculation means (52); an accelerator pedal reaction force generation means (80) for generating an actuation reaction force for an accelerator pedal, according to the accelerator pedal reaction force command value which is calculated by the accelerator pedal reaction force calculation means (53); a driving intention detection means (54) for detecting a driving intention of an operator of the subject vehicle; and an accelerator pedal reaction force modification means (52, 56) for adjusting the actuation reaction force to be generated for the accelerator pedal, based upon a detection result of the driving intention detection means (54).