I'm not sure of any right answer but I have terminated each leg of my spidery creation with portals hidden inside tunnels 1) so my trains disappear and return a period of time later via another adjacent or distant portal, 2) the creation can be extended at a later date without too much redesign effort. The properties of portals can be set so that loaded trains return empty, empty trains loaded and so forth. Even loaded trains returning loaded look different and you seldom see an empty container train in reality. Peter