Connecting Traffic

[Eric.B]

Of course it will improve it because you save a lot routes where you don’t need to calculate a 3rd leg because there are enough 2-leg connections.

It’s like a passenger: If you have for example 10 routes with good rating Birningham->london->New York you stopped checking if you find a 3-leg-route Birmingham -> London -> n (Amaterdam/Frankfurt/Paris/and so on) -> New York. So you can save the exponential n calculations…

Routing system is much more complex and realistic than that. See the explanation of the data grid system in the past AeroMogul updates on the FBS forums.

But for a short overview, passengers generally don't care what airports they're going to. Their destinations are not airports. It's areas. I don't have the game in front of me right now, but using your example, Birmingham is well served by 3 airports. If the passenger is willing to travel a little, 7 airports, and infrastructure is good enough in the UK, they could save even more just taking a train to London, 8 airports. But then if they're willing to take a train for an hour, Manchester and Luton aren't out of the question. 10 Airports. On the other side, New York area is served by 9 airports.

For 2-legged flights, you have to work backwards and forward from these airports finding matches in the destinations at each ends. Then score those flights.

When you add a 3rd leg, you have to process every route that has services to the destination and departure area, and then process every combination of direct routes between those routes. Which even, if just a small subset of of grids need 3-leg processing, it's still quite expensive thing to do.

Looping through routes to find these matches is very expensive. As is sorting the results.

If it currently takes me 1 second to do 1-leg, and it takes me 5 minutes to do 2-legs, 3-legs would take 30 minutes (or more). If only 10% of the grids need 3-leg processing, it would still take 3 minutes.