In this paper, the effects of different kinds of lights on dark spots of residential streets at nighttime are studied.
The measurements of illuminance on road surface and the subjective evaluation of the dark spots are carried out to investigate the distribution of dark spots. Based on the result, the dark spots can be classified into two types. One is seen over intense lights, e.g., the light from vending machine or shop. The recognizable distance of this type is long. The other is seen in low luminance spaces.
According to the result of the examination of pedestrian paths, it is obvious that people avoid these dark spots. This might mean that people feel uncomfortable toward these dark spots.
In conclusion, in order to decrease the number of dark spots, it is desirable to avoid that illuminance on road surface fluctuate rapidly.