SAFE VISIBILITY-BASED METHOD AND SYSTEM FOR MEASURING AND ESTIMATING LIGHTING STANDARDS IN TUNNEL MIDSECTIONS

摘要

A method based on safe visibility for measuring and estimating lighting standards in tunnel midsections: a) configuring the lighting environment in the midsection of a tunnel; b) placing a target object in said tunnel midsection; c) having drivers drive vehicles at different speeds toward the target object and measuring the various distances, D, at which the target object is seen by the drivers at the different speeds; d) re-configuring the average luminance, L, for the tunnel midsection and repeating steps b) and c) so as to obtain the visibility distances, D, corresponding to the multiple sets of different luminance, L; e) using S-model to fit the multiple sets of visibility distances, D, to the luminance data, L, and obtaining the relation model formula of D and L being L=0.683/(5.575-ln(D)); f) applying the safe stopping sight distance, D0, for the speed limit in the tunnel to the model formula and obtaining the dynamic minimum luminance, L0, required for the tunnel midsection in the lighting environment of the tunnel. The present method enhances the accuracy of safety assessment for tunnel midsection luminance, is simple in operation, and provides reference evidence for road transportation safety research. Also provided is a system for implementation of the present method.