Here is one way:
Make an invisible tilemap (green area) as on this picture:
Tilemap should not be solid.
For Car in pathfinding properties set Obstacles:Custom and in evens add that green tilemap as an obstacle.
But if you have lots of cars moving in different directions, this trick will not work.
You might need to use some other method instead of pathfinding.
Hi man and thanks for the help. It's a great idea! But as you said, that's the true, i want to create a AI traffic system just like GTA1 Top down. I never fund a post that talks exactly about that. I found some .capx, but they didn't helped much. i thought for once i could build up a traffic system using pathfinding, but as i tried in many ways before, it won't be possible for various cars, right? Thanks anyway.