Methods of three-dimensional sight distance inspection for highway

In order to accurately calculate the actual sight distance in three-dimensional space,combined with road alignment in horizontal,vertical and lateral section,a three-dimensional(3D) calculation model and 3D sight distance calculation model of road alignment are proposed,based on driving sight distance for highway.By inspecting the height relationship between an arbitrary point of line of sight and associated road point,the authors judge whether the surface and roadside cause occlusion about line of sight.Finally,the authors put forward the procedure of three-dimensional sight distance test.This model provides realization means for automatic checking of 3D sight distance and offers technological support for safety appraisal by using 3D sight distance.2 tabs,5 figs,10 refs.