I created a station with four tracks and I created four trains, to make sure that there can only be one train on every track i need 4 Id’s, one for each engine. I’m still looking but I havent found another way to make this part of a station fully automatic.
You could give an engine 2 Id numbers say 1 and 3. This would make an engine go the same way as number 1 then next controler will send them different ways. Or you could use a control track which means you don’t need to use ID numbers. With this way the next train will go to another track and you can make it as big as you like. Go to my web site for more control track ideas. I have tryed to show you both ways to do it in a couple of demo’s. Just manually push the big trains. If ya need any help let me know.