(Important) Has the train pathing changed?

[SkySo1dier]

Guys,

Have the train AI changed? See the image below. As far as a week ago the trains would fill the lower holding sidetracks, now they just go and wait sequentially at the first signal. This brings the entire adjacent section of the train network to a halt because the trains instead of going into the holding sidetracks instead end up clogging the network.

This is rather critical -- would love to see a fix to this as soon as possible. Thanks!!!

Deadlock.jpg (978.15 KiB) Viewed 3976 times

[Choumiko]

The only thing i'm aware of is this: https://forums.factorio.com/forum/vie ... 536#p56536
Don't know if/when this chage was released though. If it is out, maybe splitting your holding tracks into 2 blocks solves the issue?

Edit: Seems like it solves it.

I stopped the upper 3 trains and watched what happened

[SkySo1dier]

Edit: Seems like it solves it.I stopped the upper 3 trains and watched what happened

I've just uploaded the latest save -- you will see the trains piling up

https://drive.google.com/open?id=0B6xL_ ... authuser=0

[cube]

There was one change in 0.11.6 (last one in features: https://forums.factorio.com/forum/vie ... f=3&t=7256 ). I don't know much about it, though.

[ssilk]

As far as I can think about: if you just double the train signals before the train station this should help. Don't place them too near (But I think meanwhile they are marked as inaccessible, if they are sitting too near).

[kovarex]

This is related for sure, as now it looks 2 signals ahead, and they are red, and as the logic is very simplistic it doesn't care whether both or one of the is red.

There could be done few quite easy steps to make the route planning much more intelligent, I will try to look at it for the future versions.

[roy7]

I think I understand the explanations and issue now. If all paths are red 2 steps away, it just uses the shortest path (or whatever method of choosing a route) and that's why the train is blocking. The end destination is red and some of the intermediate switching tracks are red or green, basically like this:

GR
RR
RR
RR
GR
GR

(The RR are where two trains are already backed up and both signals are red.) Since there's no green path through, it treats them all the same. And so the work around Is to defeat the lookahead logic by adding an extra signal of very small distance before the switching sections like ssilk said. Then the setup is more like:

GGR
GRR
GRR
GRR
GGR
GGR

where the first G is the tiny short extra signal. And now the trains will move to the GGR lanes instead of waiting for a GRR lane.

Am I understanding all of that correctly? Thanks!

Edit: A simple way to address this in the game might be to choose the route in case of multiple blocked paths where the train comes to a stop the shortest remaining distance away from the station it is trying to reach? Of course, if your switching area is huge, it might be "shorter" to wait where it is instead of move to a switching lane. But maybe remaining distance at the furthest red block could still be the tiebreaker after moving ahead as many green stops as possible.