An Experiment is being carried out at Car rat Lane in the Borough of Wadsworth on the effect on visibility in street lighting of laying ad light coloured road surface. The light coloured surface, ad rolled asphalt with surface of white calcined flint, replaced a variety of darker bituminous surfaces. Measurements of road luminance have shown that the new surface gives much less preferential reflection than the old surfaces but more diffuse reflection. The mean luminance under street-lighting has been reduced, which by itself would be an adverse effect. However the luminance varation has been reduced and the luminance pattern has been converted from a predominantly longitudinal one to predominantly transverse one both of which changes are beneficial. Using data by de Boer en Krudsen only a small improvement in the effectiveness of the lighting is suggested but subjective appraisals by Laboratory observers suggest an appreciable improvement. It is hoped that the change in surface will lead to a reduction in the number of accidents occurring at night. However, sufficient accident data are not yet available to make an assessment.
Abstract