A project I am working on right now features a lot of "traffic" in the sense of cars moving along roads, aircraft moving aroun an apron etc.

As of now the available paths are precalculated, so nodes are generated automatically for crossings which themselves are interconnected by edges. When a character/agent spawns into the world it starts at some node and finds a path to a target node by means of a simply A* algorithm. The agent follows the path and ultimately reaches its destination. No problem so far.

Now I need to enable the agents to avoid collisions and to handle complex traffic situations. Since I'm new to the field of AI I looked up several papers/articles on steering behavior but found them to be too low-level. My problem consists less of the actual collision avoidance (which is rather simple in this case because the agents follow strictly defined paths) but of situations like one agent leaving a dead-end while another one wants to enter exactly the same one. Or two agents meeting at a bottleneck which only allows one agent to pass at a time but both need to pass it (according to the optimal route found before) and they need to find a way to let the other one pass first. So basically the main aspect of the problem would be predicting traffic movement to avoid dead-locks.

Difficult to describe, but I guess you get what I mean. Do you have any recommendations for me on where to start looking? Any papers, sample projects or similar things that could get me started?

I appreciate your help!