Visual Performance Models in Road Lighting: A Historical Perspective

摘要

The use of visual performance models in road lighting is an old idea: it was first proposed in the 1930s by Waldram with the Revealing Power, and by Roper and Howard who used the notion of visibility distance. The Visibility Level (VL) concept was then proposed by Blackwell, and the Relative Visual Performance by Rea and Ouelette. At the turn of the 21th century, some standards have considered using the VL in order to rate lighting installations through the Small Target Visibility concept. However, the use of visual performance indexes in lighting standards was recently withdrawed, which raises a question: what happened?