Limit on rail yard decision making?

[Plawerth]

Is there a limit on the number of rails a train select in a huge rail yard? This huge rail system is failing because the train in the top right does not want to go down to the bottom and pick an open path.

Instead it wants drive right through the topmost rail path where a train is already parked.

[Loewchen]

The limit is just for this particular setup. The pathfinders markup for an occupied station is finite, so at some point the train will chose the closest occupied station over a longer travel to reach an unoccupied one. You can circumvent that by having all stations equal distance from the entrance.

[Jap2.0]

Also, not sure if this would work, but you could have a few stations before your drop-off station, disabled by default, but enabled if there is a train in the station (with detection via signals). If it works how I think it should, then it will add a significant penalty to the station, but only if there is a train there.

[impetus maximus]

so even if you force a recalculation at the start of the stacker, it won't go for an unoccupied lane?
could you try adding a stop just before the stacker to confirm plz?

[Engimage]

Is there a limit on the number of rails a train select in a huge rail yard? This huge rail system is failing because the train in the top right does not want to go down to the bottom and pick an open path.

Instead it wants drive right through the topmost rail path where a train is already parked.

The problem in your setup is that both entrance and exit in your railyard are from the same side (top) which makes every next parking slot a longer distance. A busy station adds a penatly (a 1000 tiles if I am not mistaken) so when a parking slot is more than a 1000 tiles longer pathfinder will prefer to wait other than going longer way.

To fix this issue your parking should have an entrance from bottom right and exit at top left then every parking slot will have almost exact length so every slot will be used.

[MeduSalem]

The problem in your setup is that both entrance and exit in your railyard are from the same side (top) which makes every next parking slot a longer distance. A busy station adds a penatly (a 1000 tiles if I am not mistaken) so when a parking slot is more than a 1000 tiles longer pathfinder will prefer to wait other than going longer way.

To fix this issue your parking should have an entrance from bottom right and exit at top left then every parking slot will have almost exact length so every slot will be used.

Now's the question if the train is supposed to halt at the station OR go through the station without halting.

If it's supposed to halt then the location of the exit doesn't matter and OP found a quirk.



I think Loewchen's approach of making every station equally distanced from the common entrance is a better approach to give each station an equal chance of being chosen... and I think even then it isn't fully guaranteed it won't happen as well when a train for whatever reason doesn't feel like recalculating its path in time when another train before it choses to take the exact same station.



That said I haven't encountered problems like the one from OP yet... because I've never had such a mega base that required that many parallel stations... so I can only speak from a hypothetical viewpoint.

[Engimage]

I think Loewchen's approach of making every station equally distanced from the common entrance is a better approach to give each station an equal chance of being chosen... and I think even then it isn't fully guaranteed it won't happen as well when a train for whatever reason doesn't feel like recalculating its path in time when another train before it choses to take the exact same station.

On the screenshot I did not see any stations in the stacker. This effectively means this is a common chain signal stacker and the distance to the stacker point makes no difference while the total path length for every stacker line means something. In this case my solution will work.

I am not even talking here about the total ineffectiveness of this stacker. For such a big number of trains it has ONE output with a single block which limits throughput dramatically. It makes sense only for storing trains for continuous throughput but I would never build something like that for any purpose. Just makes no sense to me.

[MeduSalem]

On the screenshot I did not see any stations in the stacker. This effectively means this is a common chain signal stacker and the distance to the stacker point makes no difference while the total path length for every stacker line means something. In this case my solution will work.

Ah my bad... I thought they are all supposed to be parallel stations and not just a signaled stacker.

Then your solution of placing the exit on the opposite end of the entrace will work of course... because then every parallel track of the stacker would mean equal path length.

[Jap2.0]

On the screenshot I did not see any stations in the stacker. This effectively means this is a common chain signal stacker and the distance to the stacker point makes no difference while the total path length for every stacker line means something. In this case my solution will work.

Ah my bad... I thought they are all supposed to be parallel stations and not just a signaled stacker.

Then your solution of placing the exit on the opposite end of the entrace will work of course... because then every parallel track of the stacker would mean equal path length.

Same here, thought it was stations. In this case, that will work perfectly fine. What I'm wondering is what the stacker is for. Is it train storage? I doubt it's for a station considering the 1 track of input and output would only support a small station, which wouldn't justify this large of a stacker.

[Plawerth]

OP here.... after fiddling around, it seems that lengthwise stacking seems to work better.

[impetus maximus]

i really wanted to see if the first stacker would work if you forced a recalculation. for science.

[Jap2.0]

i really wanted to see if the first stacker would work if you forced a recalculation. for science.

You should be able to build it yourself. Just place a stacker blueprint 35 tracks high, and build a couple random stations past that.