How about the “gate exit” solution I suggested? Cause pax comming out of a gate necessarily pass through a checkpoint. This checkpoint only would be non-return and pax would only request a pathfinding after crossing the checkpoint.
This avoids double requests for path finding and also the zoning subdivision. Then it’s up to the player to build the arrivals corridor in a way the pax wont be able to access the departure area.
@Olof, maybe an even simpler solution:
Add to the game the “2 story stand”, where pax enter and exit the jetbridge in 2 different floors. Then it’s up to the player to “isolate” the arrivals floor so pax won’t mix back again.
Issue solved without changing anything substantial in the game.
Maybe if that happens, you could just have an notification for an error that a passenger is stuck, and then the player would have to figure out to remove the door, and delay the flight. When one way doors would be unlocked, the game could also have a warning message 
that tells people about one-way doors and the possibility that passengers could get stuck, and a screenshot of what their suggested use is.
I think that if someone is mentally confused 
enough to put a one way door on a bathroom (assuming that their language is in Airport CEO) then maybe the game doesn’t need to take them into account? How does someone ever think that that makes sense!?
What’s preventing arriving international passengers from just wandering off and shopping in the international departures zone?
Is a good improvement, but this doesn’t solve the departing passengers in baggage claim area problem.
It is not possible to have the baggage claim area inside the secure zone so it would be a security exit after baggage claim? This can solve at least one problem.
Completely agree, it feels like we’re being undermined as enthusiastic players in our ability to create coherent airport design!
PS, I recognise one of my workshop creations, Coventry Airport in that picture? 
I actually understand why such a though happens. We are always considering as “if I go and use one way doors” perspective but we don’t consider as “if (someone else who has 0 idea what he is doing) go and use one way doors” perspective.
A million $ question is: What would happen is player builds a one way door to bathroom entrance and there is no exit?
@Olof I have a suggestion for it. I call it “Flush the Problem”. Let’s say player made a bathroom with one way door and a PAX stuck in there. If pathfinding finds no way to exit the loop, he will “get flushed” out of game world.
After all, it is player’s responsibility to find the problem of vanishing people.
I feel like even a novice player would eventually see the error of their design. You learn as you play, I did.
I feel like even a novice player would eventually see the error of their design. You learn as you play, I did.
100% agree. Even I made some mistakes and send bug reports to developers.
Yes that’s the one, it looks pretty good
The example of the one way door in a bathroom setting is not what the devs are the most concerned about as that is something that somebody can figure out for themselves. It’s more that if you want to build a bagage claim next to the arrival hall for example, use a one way door to let people get to that room, place seating and toilets in that room, that could cause PAX to actually choose for the seating in the room next door or use the toilets in that room, then these PAX are stuck. So not so obvious for the starting player or maybe even the average player to notice, but causes a lot of issues which the devs then should solve in code, better said the players demand that as they need to understand what is going on and how to solve it. As Olof already described a couple of times, they have thought this through very thoroughly and looked at all kind of different scenarios and have seen bug reports of past features that caused all kinds of unforeseen issues.
I think we can still have an open discussion around this apparently ‘hot topic’ and maybe can find a suitable solution that even could work for the devs, but we really have to stop stating that this is ‘a must have’, ‘a game blocker’, ‘makes the game unplayable’, etc. As the devs knows best what is and is not possible at the moment in the game based on code and what kind of ‘flood of bugs’ they can expect if they create a certain feature in this moment in time. Olof has been very kind to explain very clearly what their considerations are and have been so far and why they will not implement it now, but will keep it on their radar for a future release or during Beta.
As an example, even on one of the biggest airports in Europe called Schiphol the PAX flow is not separated by one way doors and the departure and arriving PAX are all walking on the same floor, so it’s definitely a must have in real life, so be creative and try to solve it with the tools we have at hand today
Or… If a person cannot find a way out from an area that does not go thru a one way door, they just go thru that door.
Thanks for the detailed explanation.
From the explanation provided , it is very clear that such a feature is practically impossible to implement over the current base code.
So what are the most requested uses of the one way door?
Baggage Claim : Is it possible to solve this simply by having the ability to build baggage claim before the secure exit? Or have a toggle somewhere in the settings where the player can chose whether they want to play with the baggage claim before or after the exit
Seperating passengers on Arrival : This might be a little more complex. @Olof would it at all be possible to add a toggle to the stands where you can select that arriving passengers deboard on the ground floor? Or any floor for that matter as long as the jetbridge is built for the stand and the selected floor exists. For stands without a jet bridge , the passengers simply mix. Similarly for a Remote bus stop you can maybe add such a dropdown to select the floor for deboarding passengers. The compromise from the players side will be that we just assume that there is elevator/stairs inbulit into the jetbridge. Or if you want to go one step further maybe the artwork for the remote bus stop can include a “dumb elevator”.
I have no idea about coding so these ideas can be very stupid but another alternative option could be to add a waypoint for arriving passengers. This can be anything artistically, but the arriving passengers can be hard coded to cross this waypoint/flag, before doing anything in the airport. The waypoint can be placed anywhere by the player before the secure exits and the passengers will cross the waypoint before addressing any of their needs. The problem here is that even after crossing the waypoints , the passengers can still decide to turn back and decide to relieve themselves in a toilet thats in the “departure zone”. This can be avoided in theory by having all the facilities close to and immediately after the waypoint.
But that’s a pure PEBCAK error, not game design’s error.
But from the game’s perspective I already saw in the game’s past PAX ignoring zones or teleporting to the closest place in the correct zone where they could pathfind to their destination in some situations, like after being deboarded from a bus at remote bus stand onto service road which for some time can’t be marked as secure anymore, because there was a plant put in the corner on the bus stand that in its intent was for visually blocking access to the road, of course that’s after repeated notifications; or departing PAX with long way between boarding desk and the stand who didn’t make it to their plane on time, because the plane needed to depart 30 minutes before the departure time, they were returning to the terminal ignoring zoning and also sometimes teleporting into terminal.
For baggage claim it would help to only allow arriving passengers into the zone. Then you might just have to make the area a bit bigger to block a whole room / part of the building.
For the gate, I thought about an option to make the lanes of the boarding desks only walkable for passengers who are actually boarding (and of course for employees at any time). This would solve two problems, first force arriving passengers onto another way and second also get rid of waiting passengers always walking though the desk and back long before boarding starts.
You wouldn’t have the pathfinding problem for the way back because departing passengers only walk through when actually boarding the plane.
The only risk would be players not building another way out for arriving passengers. But if it’s only an option (either game option or setting for each desk separately) and preset to current behaviour, it should not affect new players because they simply wouldn’t set that option. If the option is set and no other way out, passengers would just stay at the end of the jetbridge and complain about not finding a way.
This wouldn’t need any new item and I hope the logic to implement wouldn’t be too complicated. Of course it’s on Olof to judge how complicated or risky it would be.
Of course it’s ultimately up to the developers what is deemed suitable for the game, but I feel like we should point out that this is a game developed for purchase on Steam, a platform designed for gamers. The game is a simulation game, for players who enjoy strategy games. Strategy games entail challenges, consideration, thought and planning.
I don’t want to suggest for one minute that I’m some super-informed target market guru or anything, but is this game ever going to appeal to an audience who want this to be overly easy or simplistic? Strategy games in general are hard, until they’re easier - rather than both naturally easy and optionally hard.
And I commend the efforts being put in place to make this game appeal to as wide an audience as possible - it definitely deserves a big following! I just fear that the game might become too dumbed down, to the point where it loses interest amongst its devout early access supporters and new/novice players further down the road.
There’s elements to this game that I didn’t initially think were clear or simplistic eg. Remote stands, but I learnt how to do it through trial and error. That’s what has kept me coming back, to create vast airports that I enjoy running.
I have faith in this game though, I hope my passion isn’t mistaken for a good old english moan! 
I completely disagree with you on this. I respect enormously the dev’s work. This is not a matter of consideration. But the aim of the forum and alpha stage development is to be able to interact with players during development and use feedback for taking decisions. And fur that purpose my honest opinion is that this is an absolutely necessary feature for late game to be good, much more relevant than de-icing, automatic check-in and other stuff the game already has.
That said, I do understand the code challenge and we’re trying to determine solutions that won’t add to the devs code challenge.
I believe we already got to that point where devs can think through new ideas that were given.
Indeed, the issue seems to only appear for boarding gates and baggage claim.
So we don’t need a one way door solution.
What solves the problem (and is much simpler) is:
(A) allow the player to place baggage claim in secure zone (btw, it should already be like this, as in the majority of airports, especially after immigration is introduced);
(B) allow arriving pax exit the jet bridge in a different floor than departing pax;
(C) make the corridors on boarding gates one-way for pax, just as security checkpoints work.
@olof, could you please consider the above and let us know your thoughts.
Thanks for the real in depth explanation! I guess that wraps up that topic
Same goes for that case.
As long as PAX cannot leave the airport area and as long as PAX cannot board the airplane, it is considerd as “stuck” so same idea will be executed for him too.
As you said @Puma , he went in bathroom and he cannot get to baggage claim area due to a one way door. Eventually path finding finds no way to find a path. He and his baggage will be “flushed” out of game world too.
Olof I think it can be tried out in Internal branch.
I think a lot of you guys misunderstood the technical difficulties Olof mentioned. Almost everything you hope to “solve” with one way doors, would create an issue with pathfinding instead. When finding paths to seats, bathrooms, shops, and restaurants the game doesn’t consider where the pax/employee will be headed next, and doing so would be too computationally expensive. This means that departing pax would walk through a one way door to access something in the “arrival” area, and then be unable to make it to the boarding desk. So instead of keeping departing passengers out of arrival areas, one way doors would just create a bunch of stuck passengers.
One possible solution Olof didn’t mention would be restricting usage of one way doors so that they can only be used to route passengers to the next primary destination( check in, security, boarding etc…). The problem here would be explaining this functionality to people so they don’t use these doors for anything that would have restricted pathfinding.
With the issues that the devs pointed out this would also be my suggestion.
An upgrade to stands called multi-story jetway(bridge) and being able to select per stand on which level it’s allowing pax to enter the stand and at which level pax will disembark.
This segregation at the gate is seen on multiple large airports and only changes the starting point or destination of the path finding without the need for extra checks/requests.
Furthermore this would allow individual CEO’s to decide if the want to use it and how they implement it in their airport design.
