a very complex looking behavior sometimes comes from the very simple easy to implement principles, like say a bird flock behavior https://en.wikipedia.org/wiki/Flocking_(behavior)#Rules

I don't believe people are using their full AGI when driving (and the full "AGI" may as well happen to be a set of basic pattern matching capabilities which we haven't discovered yet). After decades of driving the behavior is pretty automatic, and when presented with complex situation following a simple rule, like just brake, is frequently the best, or close to it, response.