A beam radiator that radiates visible light beams having a predetermined wavelength onto a road surface to inform drivers of other vehicles of the existence of a self-owned vehicle or to let a driver of the self-owned vehicle confirm a traveling path thereof is disposed in a front portion of a body of the self-owned vehicle. An optical filter is disposed substantially all over a windshield in front of a driver seat. The filter is designed to have a characteristic of being more permeable to light having wavelengths close to a wavelength of visible light beams radiated from the beam radiator 24 than to light having a wavelength different from those wavelengths. In this construction, the driver is prevented from finding it difficult to visually recognize a visible light pattern resulting from visible light beams radiated from the self-owned vehicle or another vehicle owing to sunlight or the like, and visual recognizability of the visible light pattern is enhanced.