Delivery trucks stuck

[Steve2..3]

After unloading the delivery trucks don't leave the airport anymore.

Sent the save to bugs@...

[Steve2..3]

Edit: Reloading the game makes empty trucks driving away.

[Steve2..3]

Because of the traffic jam now, pax and worker can't come to/leave the airport.

The trucks don't get unloaded anymore because they can't go to the delivery zone anymore!

[modair]

You can trie to re-load your game , sometimes it helps :)

[Steve2..3]

For already empty trucks only which can't go to the exit due to the traffic jam.

[LVGameDev]

Okay, so as best I can tell this is just a road layout issue where there is a single intersection (in a very tight space) that, due to the 'tight loop' that exists on the road layout here, it basically causes full on gridlock.

Essentially I'm seeing that the trucks blocking the "exit turnoff" are trying to get to the supply dropoff area; they're unable to do so due to being blocked by trucks who are trying to leave the airport (they managed to drop off their supplies already). The trucks who want to leave the airport are blocked from "exit turnoff" by the aforementioned want-to-deliver trucks.

There is no advanced "gridlock avoidance" code/AI for the vehicles, they generally just proceed as far as they can until they hit traffic, and then they wait. They do then attempt to re-path around any traffic, after being stuck in the traffic for a few moments (which causes some unrelated efficiency & visual issues of its own), but generally that will only help them move around traffic or consider using an alternative secondary route if one should exist.

Check out screenshot & the annotations/notes here (and below): https://imgur.com/a/S570E1K

On the screenshot, NOTE the intersection just under/left of the "Star". This is the "key problem" intersection. That specific intersection allows for both inbound vehicles & outbound vehicles to block each other completely. In the worst-case they can indeed become completely grid-locked and perma-stuck.

Despite it being a non-ideal road setup, the ideal world here would be:
A) they wouldn't ever be able to get grid-locked like this, or;
B) they'd eventually be smart enough to recognize it & get out of it, even if just driving through each-other temporarily, or;
C) player is able to initiate an action to force them out [this is how I got the screenshot since the vehicles were fully grid-locked upon opening the save initially].

Thoughts?

[LVGameDev]

PS -- Sent your save back to you after "un-grid-locking" it in the meantime, until we have a chance to decide on & implement something that's a long-term solution to this type of situation. :)