Various waypoints are simply unreachable by an AI driver.
Repro 1: Chotain military base to Levie with a Ural 4320
1. Spawn a Ural 4320 + crew at (7429, 6, 6644) using GM, drag them into the truck
2. Give the group a waypoint at Levie town center or basically anywhere south of that position along the coast
The truck will for some reason turn right at approx (7490, 0, 6210) after the co-driver opens the gate, trying to go up a very steep bank even though their path is straight. The front left wheel will leave the ground and make it impossible to continue after multiple reverse attempts.
A workaround I use: Overriding the frictionCoefficient with a delta on the Ural prefab to 0.1 alters their steering just enough to make this path possible after a couple of attempts however there is obviously a problem with the road network or navmesh at this point on the map since they are swinging right to travel straight, and I can only assume there are more instances of this problem at other corners around the map. All vehicles perform this strange turn but most are able to continue as they have the torque necessary to get up the bank, only the trucks get stuck.
Repro 2: Levie to Western Heights (any vehicle)
1. Spawn any vehicle with a crew in Levie
2. Give them a waypoint to the dirt roads near Western Heights ie (7627, 270, 3664)
They will drive through the military base and up the dirt roads then stop, turn around and try a different route to the west, stop, turn around etc. Western heights seems to simply be unreachable by them even though there is nothing physically blocking them.
These issues are making it difficult to spawn driving AI as I have to override base-game configs, navmeshes and/or blacklist entire regions of the map from their waypoint generation. Ideally we should be able to trust the navmeshes and road networks provided in vanilla or by addon map creators
Bonus problems with driving:
1. In general, truck driving AI will need a three point turn to go around just about any corner, even though they have plenty of room and turning circle to do the turn normally at a slow pace. tweaking the ChimeraAIVehicleControlComponent values can help in a lot of situations but I don't believe this should be necessary
2. A vehicle's engine is switched off if no observer is within 1000m, even if their occupants are spawned and have a waypoint. In order to make vehicles drive towards players from a distance requires hacks to pin their LOD and/or make them an observer (spawning AI near them for the entire route). It would be nice if we had a way to switch off this behaviour, unless there already is and I dont know about it