Factorio Forums

So I've managed to work out what was going on after some fiddling.

If you:

1. put a train in a location where it cannot path to anywhere (in my case a dead end)
2. open up the train gui (hit e while hovering the train)
3. try to path somewhere and it says on path
4. leave gui open and switch to manual mode
5. reverse until you now have a path
6. temporary station still says no path

You have to come to a complete stop before it recognises that you can now path to where you are trying to go

While the train is rolling backwards the pathing forward will not work.

I think this is a side effect of double headed trains, where one locomotive is the main one and can be in forward or backward mode (pulled by other locomotives then). A double headed train will never reverse direction while on the move. It can only switch around at a station.

But i can click a station in the schedule to go to while rolling backwards and it works by stopping the train and then moving forward.

There is 100% a difference between the logic that handles the temporary stations and normal stations, bug or not I think both should act and respond in the same way.

I probably should have mentioned that this is with single headed trains, not tried dual headed.

Here's a visual demonstration: https://streamable.com/ixwpr

finally i understand this topic after seeing the video !

Yes it is weird the train is able to understand it is allowed to switch direction to go to regular station but not temporary station.

mmmPI wrote: ↑

Fri Jul 19, 2019 10:37 am

finally i understand this topic after seeing the video !

Yes it is weird the train is able to understand it is allowed to switch direction to go to regular station but not temporary station.

Same here (finally understood).

After some testing, train is most likely not allowed to switch direction when moving. I think for one tick it enters "no path state" in this direction and then repaths trying searching both directions. This can be verified in setup where train is setup like:
"A===<--[train]-->===B"
where schedule is set to "first A(waypoint), then B". Train will go to A, halt then change direction and go to B. but if there is long track going from station A to the left (even long one) where there is some kind of loop (like https://cdn.factorio.com/assets/img/blo ... r-case.jpg), train will choose to go for long journey instead of reversing.

If the auto-stopping would be allowed for waypoints, it would be too much of an easy tool to stop instantly when driving it.

mmmPI wrote: ↑

Fri Jul 19, 2019 10:37 am

finally i understand this topic after seeing the video !

Yes it is weird the train is able to understand it is allowed to switch direction to go to regular station but not temporary station.

I should have made a video myself, it didn't even occur to me

kovarex wrote: ↑

Fri Jul 19, 2019 12:30 pm

If the auto-stopping would be allowed for waypoints, it would be too much of an easy tool to stop instantly when driving it.

I'm not sure how much quicker it would really be to open the gui and pick a path to instant stop the train then flick to manual mode compared to just breaking, but considering you can just choose to go to a station while reversing and it stops you seems to me like both should act the same way.

Perhaps the "fix" is to either not instantly stop a train while reversing and apply the usual breaking force, or simply prevent switching to Automatic mode (waypoints and stations) while reversing and display that as an error rather than "No path to destination", because that error is what got me confused because I knew there was a path after i started reversing.

AlmightyJu wrote: ↑

Fri Jul 19, 2019 9:19 pm

mmmPI wrote: ↑

Fri Jul 19, 2019 10:37 am

finally i understand this topic after seeing the video !

Yes it is weird the train is able to understand it is allowed to switch direction to go to regular station but not temporary station.

I should have made a video myself, it didn't even occur to me

i understand stuff fast but only after a long explanation sorry

AlmightyJu wrote: ↑

Fri Jul 19, 2019 9:19 pm

Perhaps the "fix" is to either not instantly stop a train while reversing and apply the usual breaking force

Seems to me the better option compared to prevent switching mode. But is also an annoyance

It created some confusion that you have sometimes, a little abuse at your disposal, but not always, sometimes it shows up an error message.