### Author Topic: Runway selection logic.  (Read 1042 times)

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#### DrSuperGood

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##### Runway selection logic.
« on: January 24, 2019, 12:56:08 PM »
How does the runway selection logic work for ground sections of an aircraft line?

Originally a plane going to land would to take whatever runway was nearest to the line specified dock. This meant a line would only ever use 1 runway to land.

However recently (last year?) this was changed. Now aircraft should try to use any number of runways to land as long as the runway is connected to the line specified dock.

To test this out I constructed an airport featuring 1 dedicated take off runway and 3 dedicated landing runways, with dedication controlled by 1-way signs. The idea of this configuration is to optimize usage of a single dedicated take off runway while minimizing the time spent circling since landing requires more runway time than take off. Two of these airports were built some distance away and a single line with a lot of planes was setup to fly between these airports.

Now some of the time it works as intended, with all 3 runways getting used so no circling occurring. However other times I get 5-7 aircraft in a row trying to land at the same runway resulting in them circling it, with the other 2 runways seeing no traffic at all during that period. I suspect this is related to aircraft being in a queue at a take-off runway, with every aircraft in that queue going to the same runway to land. However without knowing how the system is meant to work I cannot be sure if this is a bug or intended behaviour. It certainly does not seem to be random, since statistically having 5 aircraft in a row use the same runway of 3 runways would be a 1 in 243 chance which is far lower than what I am seeing.

#### prissi

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##### Re: Runway selection logic.
« Reply #1 on: January 28, 2019, 05:06:53 AM »
The system used the number of planes that used the runway in question in the previous month(s). If there is no usage/equal overcrowding for two months, then the bias could be temporarily lost (because the number of vehicles only dates back two months). Moreover, the runway is rather decided at take off, thus for very long routes (or all planes getting off at once) there may be some empty runway at take off time getting more traffic during flight.

Take off only runways are in principle also not needed, since they will be balanced out as well.

#### DrSuperGood

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##### Re: Runway selection logic.
« Reply #2 on: January 30, 2019, 04:56:22 PM »
In my use case this does not seem to be working too efficiently... It is certainly much better than before, but there is still some work needed for the future. I commonly see from 1 line 5-7 aircraft arriving at the same landing runway while all others are empty.

#### TurfIt

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##### Re: Runway selection logic.
« Reply #3 on: January 30, 2019, 08:40:46 PM »
Did you try Bernd's patch with your use case?  Avoid Air Traffic Congestion
Needed/Needs a little work still, but seemed good when it worked.

#### DrSuperGood

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##### Re: Runway selection logic.
« Reply #4 on: February 02, 2019, 10:40:56 AM »
Quote
Did you try Bernd's patch with your use case?
No I have not. Only tried with current release version since this was observed on a multiplayer server game.