When two passenger networks are merged, convoys stop loading after reload

[Matthew]

Set-up
Simutrans 124 r11164 from Steam
pak192.comic Serverset from Steam
Linux

Steps to reproduce
1. Make a passenger network connecting several towns with buses etc.
2. Make a completely separate network connecting another set of towns with buses.
3. Join the two networks with a bus or ship.
4. Save the game.
5. Quit Simutrans.
6. Start Simutrans and load the saved game.

Expected results
The two former networks now behave as one network, with passengers transferring.

Actual result
Passengers wait at stops as though there is a single network. But passengers do not actually board convoys, at least on lines that were previously part of the second network, and sometimes not anywhere. This persists even if the game is allowed to run for several months.

Save games
1. Affected save game. The first network was the one around Manchester/Kingston; the second network was around Grays. They were merged by the ship line.
2. Another affected save game. One network was the one around Cheshunt/Kingston; the other was the one around Manchester. They were joined by Line 3. Note that Line 4, which is part of the third passenger network I created, is not affected by the bug, so it seems to only affect the merged networks.
3. The save game used to create game 2, before the networks were merged.

Observations
The reloading seems to be required as I couldn't reproduce the problem without it. But it's also possible that I did something else different and the fact that it appeared on saves after reloads is coincidental. Or that I've just made some other sort of mistake!

Workaround
Thanks to a suggestion by Danivenk: withdrawing all convoys from the linking line resolves the glitch and creates the Expected Results. Happily, this seems to persist after a reload.

[prissi]

Simutrans recalculated the routing after reloading, adding a stop or removing all convois from a line. It seems like the reloading did not trigger the route recalculation. I will have a look.

[prissi]

The games have "avoid_overcrowing" as true (1). Since the connected port is overcrowded, it will not take any new passengers. The cascades down until all transfer stops are overcrowded. This setting "avoid_overcrowding" should be really removed, or should require manual activation as it almost always breaks the routing unless experts are at work. And even they struggle to keep up.

[Oldie]

I have ever thought that passengers and goods get a "ticket" when they arrive at a stop. The ticket is not only for a destination but also a line. Thus until vehicles arrive that match that ticket, they dont go anywhere.
Is that true?

Oldie

[prissi]

No true, the "ticket" is from the next transfer stop. They will take whatever convoi comes next and servers this stop. However, they will not board if that transfer stop is overcrowded if "avoid_overcrowding" is on. "No routing over overcrowded" is safe as it just reduces the number of travellers without crashing the entire network in a cascade as more and more stops become overcrowded.

[Oldie]

Oh OK and good! Thanks, its sometimes hard to unthink something without a good wack on the back of the head.
rgrds
Oldie

[Matthew]

The games have "avoid_overcrowing" as true (1). Since the connected port is overcrowded, it will not take any new passengers. The cascades down until all transfer stops are overcrowded. This setting "avoid_overcrowding" should be really removed, or should require manual activation as it almost always breaks the routing unless experts are at work. And even they struggle to keep up.

Thank you for the explanation, Prissi. I guess that I must have set that in the Advanced Settings dialog long ago and forgotten about it. It didn't appear to matter until I merged the networks. Apologies for the false report.

[prissi]

I was relieved that it was not a real bug as this would be much harder to find ...

I think very old version had this as default setting. So maybe a simuconf.tab from that time still lingered around? Maybe copied to the personal simuconf.tab?

[Andarix]

avoid_overcrowding only makes sense if the stations have a higher capacity than the capacity of the available vehicles.

The option only makes sense together with no_routing_over_overcrowded. Because otherwise stations will become so overcrowded that it is hardly possible to reduce the overcrowding.

Since many Paksets use low capacity stations, these options should be used with great caution.

pak64.german has been using both options for many years and is still playable. It's important not to expand too quickly and to keep an eye on traffic flows.


pak192.comic had avoid_overcrowding enabled in one version. There are already threads about this in the German forum.

[Matthew]

I was relieved that it was not a real bug as this would be much harder to find ...

I think very old version had this as default setting. So maybe a simuconf.tab from that time still lingered around? Maybe copied to the personal simuconf.tab?

Thank you for suggesting this. I checked and it's not set in any of my personal simuconf.tabs. But....

pak192.comic had avoid_overcrowding enabled in one version. There are already threads about this in the German forum.

Ah, that would explain why I was confused. I didn't remember enabling avoid_overcrowding, since I have never intended to use it, but I thought I must have done it and forgotten. It is still possible it's entirely my mistake, but your explanation does make sense.

avoid_overcrowding only makes sense if the stations have a higher capacity than the capacity of the available vehicles.

The option only makes sense together with no_routing_over_overcrowded. Because otherwise stations will become so overcrowded that it is hardly possible to reduce the overcrowding.

Since many Paksets use low capacity stations, these options should be used with great caution.

pak64.german has been using both options for many years and is still playable. It's important not to expand too quickly and to keep an eye on traffic flows.

I think it's nice that it's available for players who want it. It's great that players can configure Simutrans the way that they like. I really appreciate all the work that Prissi, Hajo and others have done to make that possible. Thank you!

But I think avoid_overcrowding should never be the default setting. Passengers do not board convoys going to their destination, even though there is space on the convoys, which is very different from real life behaviour, and there is nothing in the UI to explain why that is happening. I think that's very confusing for new players (and even old ones like me    !). Without avoid_overcrowding, stops can become overcrowded, but the players can see that they have Unhappy Passengers and the Stop Window help text explains the cause.

[Andarix]

Please note that the setting is saved with the map. This means that an empty map is created with it, then the option is always activated when this empty map is loaded. Even if the setting itself is deactivated.

In version 0.6 of pak192.comic the avoid_overcrowding was activated.

...


But I think avoid_overcrowding should never be the default setting. Passengers do not board convoys going to their destination, even though there is space on the convoys, which is very different from real life behaviour, and there is nothing in the UI to explain why that is happening. I think that's very confusing for new players (and even old ones like me    !). Without avoid_overcrowding, stops can become overcrowded, but the players can see that they have Unhappy Passengers and the Stop Window help text explains the cause.

I think these options are very good.

It has always bothered me that a station with a capacity of 32 can be overcrowded with tens of thousands or even 100,000. This is the reason why you can make huge profits from passengers. Because this ensures that vehicles are always on the road with 100% load and therefore full profit.

However, if you have to make sure that there is adequate station capacity, you have to think more about stations and their space requirements. You also have to think more about the expansion of routes and the vehicles used. And that allows for more flexible play, especially when there is no requirement to have the fastest vehicle (keyword: speed bonus).

These options have been around for 15 years now and have been more or less ignored.

history.txt

Release of 102.2 (r2785)

18-Oct-2009:
    ....
    ADD: do not create goods/passenger/mail when the only route is over an overcrowded stop (simuconf.tab no_routing_over_overcrowded)


...

Release of 102.0 (r2366)

5-Mar-2009:
    ...
    ADD: avoid overcrowded stops (experimental, avoid_overcrowding=1 in simuconf.tab)

As mentioned, these options only work if the set of station capacities is adjusted accordingly.

Overcrowding in stations has been ignored by players for ages. It doesn't matter much if stations are overcrowded. If these options are active, overfilling is deadly because you can quickly find yourself in the red. Much more network maintenance is necessary here.

I had created a script tool for querying crowded stations.
https://forum.simutrans.com/index.php/topic,22159.msg202679.html#msg202679
more script tools

Unspecific error messages are a big problem anyway. Not just at Simutrans.

A good example of this is construction on foreign traffic routes. Build a bus station on a straight piece of road owned by another player (not public).

Stops can be built only on straight level matching ways!

It is a horizontal straight piece. The message gives no indication that the owner is incorrect.

In individual games this is irrelevant. But if AI comes into play or if it is a network game, then the owner is relevant.