An illumination property of headlights 4 is controlled so that light quantity or color in a belt-like region B including a virtual line segment A may be different from those in other regions, and thereby the virtual line segment A which uniformly inclines downward from an apex T deviated from a driver toward opposite sides in a vehicle-width direction is indicated on a road surface. The virtual line segment A thus indicated can suppress inclinations of forward visibility and also suppress the sway of ahead inclination angle when a vehicle turns, thereby stabilizing a driving posture of a driver and suppressing steering disturbance.