The possibility of linking routes has come up over and over, and every time Matt has addessed it he's pointed out that it can't be done because of the timetables: each route has its own, and they can't mesh. To use as a theoretical example, RRO and RSN* - RRO has its timetable, and RSN has its, and they may conflict, and neither has any trains that run beyond Hagen. But now there is a way. With the alt-timetable technique which debuted with DLGW, and which Adam apparently is applying to RT, the obstacle is overcome: owners of both routes would have access to a new timetable layer designed for both routes together. *Yes, I know there are no RL passenger services that run on both routes. Just an example. Think instead of the possibilities of Cologne-Wuppertal, or Cologne-Duisberg. Or a Munchen-Innsbruck route.