Pathfinding error

[Blacky007]

I don't know if this is as designed or if it is a pathfinding error?
see the map - its sandbox to make it really clear.

the top of the 3 "GO" stations is not acessable by any of the 6 trains.

this is the save.
https://www.dropbox.com/s/zfjjith2z82ku ... a.zip?dl=0

I had this in my main map on 3 stations with a two way staton system and the additional double block signal.
after changeing all trains from a 1-4-1 to a 2-4-2 I dont need the second station any longer. I removed it in 2 stations but not in the last one.
and that was blocked for alle the trains now???

and this is the pastebin for the trainstation
https://pastebin.com/VutwAvLr

I hope that makes it easy to fix this bug.

[Loewchen]

The top "go" station is completely accessible to your trains which can be simply demonstrated by changing its name and sending a train to it.
If you still see a problem here, describe exactly what behaviour you consider wrong and how to produce said behaviour.

[Blacky007]

the problem is that the two block signals after each other together with the reversed trains station are blocking the trains to choose the top one out of the 3 that are there
removing the second station - everything fine
removing the second pair of trainsignals - everything fine

[Blacky007]

and with this setting they only go to the middle station.

[Blacky007]

and this is the same with stations in driving direction - everything normal

it need to be the reversed station that gives an unnormal high penalty in the pathfinding

[Blacky007]

any update if this is by design or an error?

[Zavian]

Looks like you have a large set of chain signals in a loop, but no normal signals. Just from looking at the screenshot that seems to be the problem. Assuming you are using single headed trains, you don't actually want to fix your signals so that trains will use all 3 stations at once, because that would be a case of deadlock. (If you are using double headed trains then you don't want the loop). You might need to spend some time learning about how rail signals, stations etc work in factorio. I recommend the follow 3 part tutorial on reddit. https://www.reddit.com/r/factorio/comme ... ts_23_and/

[Blacky007]

Looks like you have a large set of chain signals in a loop, but no normal signals. Just from looking at the screenshot that seems to be the problem. Assuming you are using single headed trains, you don't actually want to fix your signals so that trains will use all 3 stations at once, because that would be a case of deadlock. (If you are using double headed trains then you don't want the loop). You might need to spend some time learning about how rail signals, stations etc work in factorio. I recommend the follow 3 part tutorial on reddit. https://www.reddit.com/r/factorio/comme ... ts_23_and/

the loop doesn't matter is was for testing...
my normal stations with the problem (I have 3 small together on my map) are one way in-out.
btw. you don't need to tell me a lesson about railway layout after my 2535hours ...

[Zavian]

Apologies, I didn't download the map earlier, just glanced at the screenshots (one of which was missing any normal rail signals) and thought that looks like it won't work with single ended trains, and you don't normally need a loop like that with double ended trains.

After actually downloading the map and looking at the setup. The problem is that penalty for a train stop that is not the destination is greater than the penalty for a train stopped in a station, so a train will prefer to wait for either the south or the central station to be empty, rather than path through NO-GO to use the northern GO station.

From https://wiki.factorio.com/Railway/Train_path_finding

...
When the path includes a train stop that is not the destination -> Add a penalty of 2000.
When the path includes a train stop with a train stopped in it -> Add a penalty of 500.
...