Perceived brightness evaluation of LED light in daytime fog

Investigation of the brightness of LED on traffic information board or traffic signs under foggy conditions is an important practical consideration, because LED becomes fainter and contrast is reduced. Especiaily when fog occurs at daytime, fogs appear to be whitish. In these conditions brightness of LED is much dispersion into the fog. In this paper, by evaluating LED brightness with human visual sensitivity, it is understood that in daytime fog condition and different fog densities do affecting brightness evaluation. The colored LED light that contains a red component has high brightness evaluation point and the blue component has low brightness evaluation in all fog densities. However, blue color that containing red color also has high evaluation point. This paper result can contribute to air and land traffic safety which can present further accident happen.