Tool for analysis of tunnel lighting based on visual performance and visual comfort

This study describes a method to derive a profile of the road surface luminance in long tunnels based on visual performance and visual comfort and its implementation in an excel file, which is freely available to anybody with an interest. The method presents an alternative approach to the dimensioning of tunnel lighting, compared with the method of CIE 88:2004 (CIE, 2004). As a minimum, the method can be used to reveal the influence of various parameters, such as the age of the driver. If accepted to a sufficient degree, the method can be used as a starting point for the design of tunnel lighting installations or modification of national standards. Calculations show in particular a strong influence of the driving speed – or rather with the stopping distance associated with the driving speed. At low to medium driving speeds, the transition zones can be shorter than reflected by the standard curve from (CIE, 2004).