I have seen somewhere a guide that has instructions how to force AI to enter runway for departure from 2 taxiways simultaneously (see screenshot).
I can't find it anymore, if maybe someone can point.....

I have a working RKSI with this nice thing, but I cannot replicate it in Kuala Lumpur ((( 

 

Edited March 1Mar 1 by vl1

Hi, I have worked on many AFCADs in the past and as far as I can see there is a trick here. Left of the center of the image you see the connection to the taxiway is open. It means aircraft taxiing to the runway using the right taxiway, will use the first entry to the runway. Probably came from the right side of the runway and crossed it to use the right taxiway.

The startingpoint of the runway (black line) is at the top entry and this is the aiming point. Aircraft using the left taxiway cannot get to the first entry since that taxiway is not connected and they will use the second entry.

27 minutes ago, phmcr said:

Hi, I have worked on many AFCADs in the past and as far as I can see there is a trick here. Left of the center of the image you see the connection to the taxiway is open. It means aircraft taxiing to the runway using the right taxiway, will use the first entry to the runway. Probably came from the right side of the runway and crossed it to use the right taxiway.

The startingpoint of the runway (black line) is at the top entry and this is the aiming point. Aircraft using the left taxiway cannot get to the first entry since that taxiway is not connected and they will use the second entry.

Fantastic, but this is the ADE file for WMKK and it DOES NOT work (

 

I copied the layout exactly from Seoul (first screenshot) which does work

Edited March 2Mar 2 by vl1

it all depends on the starting point of the aircraft. All aircraft starting left of the runway will use the left taxiway (shortest route). Only an aircraft coming from the right that first had to cross the runway from right to left, will use the right taxiway.

 

2 hours ago, phmcr said:

it all depends on the starting point of the aircraft. All aircraft starting left of the runway will use the left taxiway (shortest route). Only an aircraft coming from the right that first had to cross the runway from right to left, will use the right taxiway.

 

That's also easily understood, but not working.....

Thanx for your help 

Please take a look....

 

In Seoul it works with runway 15R (screenshot #1)

 

https://drive.google.com/file/d/1lR_R0tLX32wLr3GlvN4JFhGgg0yP4_yn/view?usp=sharing

 

https://drive.google.com/file/d/10sv4E_PQ49fMBp5vjmtAweFNqJmX8gFm/view?usp=sharing

If that's the ADE available on AIG forums, that would be the one by Brad & me; and I wrote the taxi logic. As the previous poster correctly mentions, it's all about "the shortest distance from starting point to runway entry." Some important caveats here. 

On the taxiing side, it boils down to a game of geometry and finding the shortest distances. If you look closely at taxiway intersections, you'll see triangular connecting links of varying size, which influence the shortest distance calculations and ultimately which taxiways AI will use. You'll also notice that some intersections don't actually have true connections, but instead the lines simply overlap. This is another way of controlling the direction of AI, and ultimately the runway entrance they pick.

For example, let's look at AI taxiing down to RWY33L from Terminal 2 (KAL). AI could feasibly pick any parallel taxiway that connects taxiways A & B (the long north/south taxiways), but how do I control which taxiway they use...? Compare the triangular taxi links for taxiways A11 and A9, and you'll see that the connecting link for A11 is 13.5m vs 11.4m. Geometrically, because A11 is a longer hypotenuse relative to A9, that is a shorter route to the runway entry thus AI coming from T2 will always use A11 instead of A9 (or any other) when headed to RWY33L.

Keep in mind that whatever shortcuts you build for departing traffic will also be potentially available for arriving traffic too (depending on where they're coming from - which runway - and where they're going to - which gate - so you have to be mindful of arrival vectoring).

On the runway side, the entrances need to be within a certain runway length from one another. I can't tell you exactly what the exact maximum length/distance is between entries (because I don't know it), but if you hover over the runway vector between the entries on RWY33L, you'll see it's a length of 26.1m (so maybe use that as a max value in your own builds...?). In order to make that happen, you can see the taxiway vector that sits on top of the runway. One side effect of this is that AI entering the runway from the southernmost entry will take a little bit longer to taxi into position compared to the northernmost entry.

 

It's all a bit tricky and definitely requires patience testing all the values, but I hope this helps.

Edited March 2Mar 2 by drobinho

As always you are soooo good

I don't want to disappoint you, and it is a shame that you spent so many time to write your big essay.

The solution was (except for aligning taxiways going to the runway, cutting connecting nodes) in apron links (not taxiways) connecting hold short nodes to the runway.
That is it!

So it is not tricky, does not depend on an airport and does not depend on anything, except for choosing correct taxi links.
Sorry you spent so much time for your work, but I accidentally found a solution, which was very easy.

Checked and working on several airports already!

Cheers, mate!

 

Kuala Lumpur

 

Houston

 

 

Edited March 30Mar 30 by vl1