Routing difficulty: Hard
Map: NE USA
I had a bizarre situation recently and it prompts the above question. For the most part I adhere to the one train per track method of routing with just a few exceptions I'd rather not get into here.
Suppose you have 3 parallel tracks running through a coal resource and leading to station NY. Each track is delivering some train consist and you now want to add a track+annexe+train to pick up coal and carry it to NY station which has a steel mill.
Now you might have chosen to lay track that forked away from the 3 parallel tracks and place an annexe uniquely on that fork ... but I did not. I routed a 4th track parallel to the other 3 and ran it to NY station. I then placed the coal annexe adjacent to this newly placed 4th track. I fully expected the track/platform nearest to the annexe to be the track/platform used by the next new train that I added with a route starting from this newly placed coal annexe and terminating at NY station.
To my surprise the new train was added to the track/platform farthest away from the annexe! That track was already dedicated to some other train+consist and would eventually lead to problems. Of course the ambiguity arises because there are now four possible routes from this new coal annexe to NY station.
Similar experiences with fewer parallel tracks has taught me that one way to avoid this problem is to wait for (an)other train(s) to be occupying any other platforms/tracks at the annexe or station and then pause the game to add the new train. That way only one track/platform is vacant for the new train to possibly depart from. However, this was a 4 track situation and I did not have the patience to wait for 3 trains to coincidentally occupy those other 3 tracks at this newly placed annexe. (I also naively thought that, unlike a terminal, an annexe would not recognize all 4 parallel tracks as being associated with it.)
So the brute force method I resorted to was to add one ... two ... three ... four(!) trains at the same annexe and sadly it was only the 4th train that was placed on the (desired) track/platform nearest to the newly placed coal annexe! ... I then deleted the other 3 trains!
Now in this particular case I had plenty of cash and could afford to create and then delete trains but that is not always the case.
- Does anyone know of a fool proof way of specifying from which platform a new train should depart a station? (e.g. Something akin to specifying "nearest" "middle" "farthest" which I seem to recall from the Transport Tycoon train routing interface.)