Natural lighting of road pre-tunnels: A methodology to assess the luminance on the pavement - Part II

This second part presents the validation procedures adopted to verify the proposed models. Particularly, a luxmeter photo-radiometer has been used for validating the clear not terse sky model and several PTL scale models were used to validate the methodology proposed to assess the pavement luminance. The geometry of the PTL, its alignment and materials have been varied to obtain several results under various meteorological and climatic conditions. The results obtained from the experimental research program showed that the proposed models, inherent both the sky luminance and the illuminance on the road, ensure a good approximation respect to the real measures performed. In particular, for the sky luminance, the proposed theoretical distribution implies an average deviation respect to the experimental data equal to 5%. The calculated illuminance under the PTL differs on average from the measured values for −1.26%.