A driver assistance system enables brake and accelerator operation by an operation bar in a manner close to a sense of a driver of a vehicle, regardless of the degree of operation of the operation bar. Embodiments include an operation bar extending downward toward a vehicle floor panel from a manual operation area where a seated driver manually operates the operation bar, and whose lower portion is supported in a slidingly displaceable manner along an axial direction in a front-down, rear-up tilted state. The operation bar includes a brake actuation section, below the manual operation area, that actuates a brake mechanism by sliding displacement of the operation bar in a front-down direction; and an accelerator actuation section that actuates an acceleration mechanism by sliding displacement of the operation bar in a rear-up direction that is a reverse direction on the same axis from the sliding displacement in the front-down direction.