Highway geometric modeling method by curvature and gradient functions

Highway alignments are designed as the sequences of elements such as lines, arcs and spirals. This method makes the difficulty to build and edit the 3-D highway - on CAD systems, because horizontal/vertical alignments and cross-sections are defined individually and each kind of elements has different parameters for shape definition. This paper shows that highway alignments can be determined by functions of curvature and gradient, and shows the schema to build the 3-D geometric -. Utilizing this method, the 3-D highway geometric - can be built with fewer data systematically, and it can be applied to the highway product - for computer-based design in future.