Game Version number: 1.2.1.127
Currently, the AI has massive problems when two vehicles come towards each other.
Usually one of them has an accident, explodes or the vehicle is damaged and the crew gets out and walks halfway across the world to reach their waypoint.
Sometimes it happens that when two vehicles are on the same road, one of them suddenly changes direction.
I have also noticed since the experimental version 1.2.1.87 that vehicles like to forego roads and drive across fields.
An accident or uncontrolled navigation is the result. The only way to avoid this is to give the group waypoints at intersections.
Currently, vehicles are nothing more than an "extra" but cannot be used for good mission design because they always behave illogically.
Sample: https://drive.google.com/file/d/1ZH7G8tFiHDhNJLQeKdjafb8qRyql1Flv/view?usp=sharing