To heighten visibility of a looking object such as a falling body and a line of sight guiding effect, by relaxing the veiling phenomenon, and increasing brightness contrast between the front of a driver and the background.

In this tunnel luminaries, of light distribution approximate to a cosine curve generally used, light intensity of 30 to 70° vertical angle in a side opposite to a traffic direction is reduced to about 0cd. Light flux in a range of 0 to 30° vertical angle in a traffic direction side and 0 to 30° vertical angle in a side opposite to the traffic direction is set to 65% the equipment total light flux. In the case of setting this tunnel luminaries in a tunnel, the veiling brightness is 33% of the conventional one, and road surface brightness is 89%. Accordingly, decreasing of the road surface brightness is compensated, and in case of ensuring the same road surface brightens to the conventional, the veiling brightness is 37% the conventional. By 50% light permeability in a 100m section, road surface brightness is 5cd/m2, veiling brightness by 110m measurement distance is 0.74cd/2, brightness contrast Cp between the 110m front of a driver and its background is 0.34, and as compared with the 0.28 conventional, high brightness contrast is obtained, and thereby visibility of a looking object is obtained.