Factorio Forums

TL;DR

A toggle able option that causes a train to reserve a train stop when it starts to head to it

What ?

Add a checkbox to the train stop GUI that when enabled causes the train stop to become reserved when a train heads to it. A train just marks the train stop as its destination, and the train stop gets marked as reserved. If another train trys to go to the same train stop, it would appear as disabled to it.

Thinking along the same lines of rail signals where trains reserve them by marking orange.

Why ?

Currently you can enable/disable train stop by conditions. A simple example would be having the train stop out put if a train is there, then reroute the output back to the station to disable when a train is there. Say you have a coal drop off station that turns off when a train is there, along with 3 trains that drop coal off there. Train A just leaves the drop off station, when train B and C are full of coal, they see the station is enabled and both head towards it. Train B gets there first, and causes the train stop to be disabled. Then train C gets there, is stopped by the signal, then sees the train stop is disabled the heads back to the coal pick up station. Train C achieved nothing but causing traffic.

With the change, train B would mark the station as reserved causing train C to never move in the first place, thus stopping the pointless traffic.

The above is a rather simple example, a more complex is take 20 stations all named "Iron Plate Unload", and 5 stations named "Iron Plate Load" with 5 trains running between "Iron Plate Unload" and "Iron Plate Load". Each station named "Iron Plate Unload" has a disable condition if it has a lot of iron plate or if a train is there. The unload stations also go though iron plates rather slowly, allowing 5 trains to fully supply all 20 stations. Say all 20 stations have plenty of iron plate so they are disabled, and the 5 trains are waiting at the 5 "Iron Plate Load" train stops with full inventory. 1 of the stations needs iron plate and is enabled, then all 5 trains go for it, just so 1 can get there and 4 can turn around. Then take the same case for every other resource and all a sudden you have 100 extra trains driving though the base causing a bunch of traffic while transporting zero materials.

I like this idea.
Infact, I just came to the forum to ask if this is somehow possible with the circuit network.
I want my trains to wait at a central stacker, as long as no outpost has enough material to fill up a train completely. At the moment, when an outpost opens, all my waiting trains head there at once.
But instead of disabling the station, I would suggest a network signal. You could also use it to control railway signals. And if you want to disable the station you could just use it for that.

Any idea if this will be a possibility?

This and the slightly improved upon suggestion to allow circuit-controlled limits on the number of trains able to path to a stop have come up a lot of times recently. No response from Wube either way that I'm aware of, but I expect Wube is at least aware of the request.

Currently it is not implemented.
Devs will not add almost any new features to the game right now as they are focused more on polishing and implementing existing roadmap.
Regarding this I had a proposal long ago that would actually cover the issue:
Train pathfinding on stations with same name

Instead of hard-coding such a feature into the game, I think it would be best if it were possible for the player to implement this (and similar things) himself using the circuit network.

If this suggestion of mine were implemented, it would be possible for the circuit network to detect the positions of trains, even when they are moving.

Also, if this sub-suggestion by forum moderator ssilk were implemented, it would be possible for the circuit network to detect the currently active order of the train, i.e. which station it is going to.

Ya, im sure there are alot of different ways they could change trains with circuit networks. I'd say the main issue is trains scale poorly currently with no good way to manage them. Being able to use same station names combined with enabling/disabling stations works rather well, if it wasn't for the stampede of trains that head for a station that only needs 1 train.

Circuit contorted limit would work just as well (and probably be better)

Not sure how path finding penalties helps with those issues. With out bottlenecks, controlling trains with path finding doesn't sound realistic that way. (not that it wouldn't be be nice to have in general)

Being able to detect where a train is or where it is going is would be nice, but with out bottlenecks to trap trains or any way to auto change other trains orders it doesn't solve the problem.

Having to build in bottlenecks to control massive amount of trains doesn't sound like a good solution (unless im missing something about those suggestions).

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As for the comment about they refuse to add anything new any time soon. Hopefully that changes soon, because in the last 1.5 years the only thing major they added is art wagons, cliffs (which id argue was poorly implemented), and graphics. Polish is great but it needs new stuff to say fresh. (not that the requested change would be major in any way. Id even argue its minor enough to fit in with their polish only plan)

I tend at this point to believe that a combination of circuit controlled limits on the number of trains and circuit controlled station priority would probably give a sufficient level of control for vanilla purposes, with mods like LTN available for people who want really advanced train capabilities. Those two alone would allow players to make sure their most important outposts are stocked first and that, as long as there's not a materials shortage, no outpost goes unstocked and also resolves the herd of trains issue, by allowing outposts to specify an exact number of trains they can support.

Bonus love for Wube for trains being able to send a circuit signal for the number of trains inbound so a station can adjust it's priority as trains start pathing to it (assuming that priority won't have any further effect once a train has already started pathing to it's destination).