Presents a new routing concept which guides the selection of wire segments in track-by-track fashion by inspecting the effects of the endpoints of each selected wire segment to column density and vertical constraint graph of the given channel routing problem. This new routing concept has been implemented in the two-layer and three-layer routers. The routing performance of the developed two-layer and three-layer routers has overwhelmingly outperformed all the currently existing two-layer and three-layer routers in most examples in the literature as shown in experimental results.
