Lagging when airport is full

the game always lags if the airport full of the plane. and when the airport empty, it works fine. how to solve this problem?

nb: my device is redmi note 5 and l played the game with low graphic and the still lagging.

As airports grow, the taxiing calculations have to be immense for the developers. I applaud their work.

Here is a situation at NGO…


Another backup at NGO (same gate (18) seems to keep getting backed up).