Design Method for the Lighting of Tunnels Based on the Assessment of the Veiling Luminance

摘要

In usual low-land situations, the adaptation of the visual system of drivers/observers follows without an appreciable adaptation lag the changes in the luminance of the immediate surround. This luminance may be assessed by adding the intrinsic luminance of the actual objects which are observed and the veiling luminance caused by scatter of light in the media in between. The system is applied in several new and renovated tunnels in The Netherlands. The high values of the luminance in the threshold zone are arrived at by applying louvres that are not sun-tight, and by artificial light, new design principles of the louvres are introduced.