Ellipsoid-based approximation method for the estimation of the actual reduced luminance coefficients of road surfaces for accurate lighting simulations

Abstract

Lighting simulations are a useful tool for developing strategies to minimize lighting pollution and energy consumption in the street lighting field. However, the properties of the standard pavements often used in simulations are out-to-date and might notably diverge from the values of the real system, leading to inaccurate results. This underlines the present need for new methods to generate models that more closely resemble the actual behaviour of the roads and the construction materials currently used. This paper proposes a novel method that approximates the reduced luminance coefficients of asphalts using a geometric estimation based on a three-ellipsoid surface. It focuses on improving the modelling of the road surface material by adapting the reflection properties of the pavement, appraising and mitigating the impacts of pavement deterioration on simulation results. The approximation method is implemented inside a model calibration framework and applied to a real scenario in comparison to other methods. Results are yielded with approximately 0.088 cd/m2 error in the luminance calculation regarding measurements taken experimentally while maintaining a realistic photometric model. These experimental figures, corresponding to a relative decrease of 26.5%, support the theoretical contribution of this research work to the management of the consumption and operation of public lighting systems.