A vehicle driving assist system executes an actuation reaction force control of accelerator pedal, a driving force control or a braking force control in a manner that is appropriate in consideration of the traffic situation in which the vehicle is being driven. The vehicle driving assist system calculates a risk potential that indicates the degree of convergence between the vehicle and an obstacle existing in front of the vehicle based on a prescribed control pattern. Then, based on the risk potential, the accelerator pedal actuation reaction, the host vehicle driving force and/or the host vehicle braking force are controlled. The intent of the driver regarding acceleration and deceleration based on the actuation state of the accelerator pedal is preferably used in controlling one or all of the accelerator pedal actuation reaction, the host vehicle driving force and the host vehicle braking force.