To limit energy costs and environmental impacts related to road lighting, luminance-based designing is the best solution to provide the right amount of light on the surfaces to be lit. But this exercise requires knowledge of the reflection properties of the road surface, which are generally unknown. Therefore, the design is often done in terms of illuminance, and luminance is estimated using the standard r -tables provided by the CIE 50 years ago. This review article presents the current state of knowledge on the reflection properties of road surfaces and the external factors (age, traffic, climatic conditions) that may influence them for road lighting applications. These factors are closely connected, and they were not addressed in isolation. However, this article illustrates the evolving and dynamic nature of the reflection properties of road surfaces over time. To characterise a road surface in a state representative of most of its life, it is preferable to wait 2 years after application, especially for bituminous roads with no initial surface treatment. Furthermore, spatial heterogeneity could be considered by taking measurements in the centre track and in the wheel track.
Muzet et al. (Mon,) studied this question.