A Theoretical Equation for the Road Surface Luminance in the Interior Zone of a Road Tunnel

This paper derived a theoretical equation of the road surface luminance for the interior zone of a road tunnel. The derived values, based on five assumptions were compared with experimental standard values. The theoretical formulas were derived by comparing the threshold of the photoreceptor cells sending signals to the brain with the assumptions, using Weber-Fechner’s law and absolute physical quantities. The results indicated that the case using absolute physical quantities closely followed the road surface luminance standard values, suggesting that the threshold of the photoreceptor cells did not follow Weber-Fechner’s law.