Evaluation Index of Visibility in Tunnel Lighting

Abstract

The revealing power was proposed as an index to evaluate visibility in road lighting. However, applicability in tunnel lighting has not been studied. We evaluate the tunnel lighting visibility on the basis of the revealing power in this paper. Our simulation and field experiment, made clear the relationship between the brightness and overall uniformity of the road surface and revealing power. This result confirms tunnel lighting can reduce the road surface luminance while maintaining visibility and can also save energy.