I have heard in Japan, certain tracks on a multitrack mainline are owned, and are absolutely dedicated to that one certain transportation Company, and only it's own trains use that certain one track, thus insuring that head on collisions are almost impossible (except where tracks cross over each other at interlockings. And a lot of their track is dedicated to only one directional running. Scheduals are absolute, and being strictly "on-time" is absolutely mandatory. Each and every signal and sign is verbally called out by both the conductor and the engineer, and acknowledged by a white glove salute, signaling that the aspect was followed through, with military precision.
I have directional trackmarkers set so that my 4 track mainline, is all laid in the correct direction of the intended traffic flow, and the two tracks are only for eastbounds, and the other two tracks are only for westbounds, and my crossoverers are locked shut for AI, so it can not select the shortest route. I can easily run trains from one end of the Pittsburgh to Enola route, without ever crossing over to another track, (which makes the command rule: "Drive", or "Just Drive" easy as pie).
There is one European route where a neck worn medallion token (cookie) is handed out to the driver of the train, and trains without the medallion can not proceed on that track, until the medallion is handed over to the dispatcher, and swapped out with another driver going in the other direction.