Questionable AI behaviour


Post a log file for that session. The devs cannot do anything about unless they have the log files to analyze what’s really going on.

Also, were you editing/modifying lines before you noticed this AI behavior?


Thanks. I added the log file.

I did not modify the lines between the point of arrival at the square station and the time the screenshot was taken.


Alright, just gotta wait until either @peter or @shiprib responds back.


Ah, I think what happened here is that because the central station is overloaded the passengers value the cost of waiting to be much higher than normal so tend to get on a less than ideal route right now rather than wait for a better, shorter option. Generally this helps you from losing because of stubborn “I don’t want to transfer!” passengers, but in this situation it probably hurt you more than helped unfortunately. :expressionless:


I see. Thanks for the explanation!
Maybe the desire for passengers to do so could be adjusted a bit? This very example shows they are willing to take an absolutely terrible route, leading to a high congestion of the train all along the way.


Try building more loops, it really works :wink:


I enjoy Minimetro a lot, but I feel that I observe questionable AI behaviours really from time to time. Today I wish to give to an example.

Please have a look at the light blue and the green line that intersect at the “plus” station. Some seconds ago, the long light blue train left the “plus” station but did not take any rectangle-shaped passengers. Instead, the long green train takes all of them. This confuses me.

From previous posts, I see the AI works with a cost approach. Isn’t the cost of changing from green to light blue higher than the shorter traveling distance?

Having screenshotted and reported this, I am even more stunned by what happened next. The green train doesn’t unload the rectangle-shaped mass at the star and not at the triangle, but at the circle. Why should this be the best idea?

I would be pleased to discuss both surprising phenomena with you or hear about developer’s background.
Thanks in advance. (I can post outputlog if needed).

Train did not pick up all possible passengers at station

Post the output_log.txt here, and the developers will take a look at it.


output_log - Kopie.txt (165.7 KB)

Here we go.


This explanation is male bovine excrement. The object of the game is for me, the player, to build metro lines to get passengers from the station of their origin to the corresponding shape destination in the fastest most efficient way. If my map sucks, the game should end with a low score. Passengers taking random ridiculous paths is not “helpful”, it is counter to the object of the game.

Since it is months later and pathfinding is still an abject failure, here is another example:

output_log.txt (246.8 KB)


Thanks for posting logs everyone - unfortunately for pathfinding bugs we don’t log enough information out for it to be useful though. Screenshots or animated gifs exported from the game are most useful.

I understand where you’re coming from @Fistandantillus7. We have spent a lot of time on balancing how clever we want the passengers to be. In this specific case of passengers taking a non-optimal route from an overcrowded station, we arrived at this after getting many complaints from people who lost their games because passengers preferred to wait for a direct route instead of taking a slightly slower route.

What won’t be helping is that we know there are a few bugs still present in the pathfinding, and it is very difficult to pin down exactly what is causing degenerate behaviour even when we can reproduce issues. We are hiring an extra person into the studio very soon whose responsibilities will include quality assurance so we anticipate this to be a big help here.


This sounds backwards to me. Users complaining that passengers don’t behave as expected is basically a user writing in to say they haven’t figured out how to build a mental model of the game yet.

But this mental model is necessary to build optimal lines. So I feel like the best response would be to make it crystal clear how passengers behave. But it seems like the choice taken was to make passengers more complex, which means building such a mental model is now even harder.


After looking into this a lot more since I made that first post about passenger behaviour, I think this is more to do with just plain bugs in the pathfinding than that weighting towards taking non-optimal routes from a crowded station.


So, Robert/shiprib, you still wish to have more bug reports on this?
I am happy to help, but could you insert a hidden “Save the moment” feature, like saving an instant screenshot or a gif of the last seconds together with storing a copy of output-log? “Save the moment” could be a triple-click on the clock or something similar.

I like “Sean Fellows” idea to make it crystal clear how passengers behave. Experienced users do want to know whether passengers prefer changes over connection without changing, after what waiting time they accept long detours… So why not post some of the Passenger behaviour / AI key baselines here?


There exists an in-engine Unity extension solution for creating GIFs in Unity games.

I would say it is possible, but I don’t think it will be in the game, because it requires the Unity Editor namespace itself to be a part of the game. This means, standalone games and mobile games will not be able to allow players to create GIFs through normal gameplay, and can only be done through development and testing.


Oh I just meant the animated gif export that currently exists in the game - click on the > button after you lose and hit the disk icon. If you could upload that plus just a regular screenshot showing where the error occurred that would be great!


Since its after a long shift, I did not read all reactions.

But the red line did a pickup on the main hub, because the square on the red line to the right is the station most close to the star if you realize that yellow can transfer from red to pink with a higher pickup-rate on the end of the yellow line as on the hub. The end yellow line has 2 pickup directions, so a higher frequency and a higher service level as the hub. The hub has a long timer on pickup for the pink line, due to it being a stretch line and not a loop, so mostly has a lower frequency. If this is not a Hard match, you can solve it by remove the yellow / red overlap.

Look @ my twitter account for some suggestion in setup without a lot of overlap.

Hope this helps.


You’ll need to at least provide a link. And if possible, provide a screenshot when you can.


I will look for a picture tomorrow, just home from 12h shift. My login on this forum is twitter, the link is in the bio, but to make it easy;


I just replied to a similar thread, but thought I’d mention it here too. We recently fixed a pathfinding bug and will be deploying it in the next update. It’s fairly major and accounts for almost all error cases that we’ve seen in the last few months. Thanks for your patience everyone, and sorry you’ve had to suffer the vagaries of misbehaving passengers for so long.