Indeed, PandaSteer has implemented several essential steering behaviors. But when I tried to implement my AI, that was not sufficient, and I found that for real-life use it makes more sense to implement some ‘autonomous pedestrians’ algorithms. As I remember, many of the geometry and trigonometry algorithms that are important for autonomous pedestrians are not yet implemented in Panda core; some of them I tried to recreate in Python (but, as you probably know, mathematics in Python is very inefficient unless you use Psyco): discourse.panda3d.org/viewtopic.php?t=5817
This includes: point-in-polygon tests, intersection tests, perp product (aka 2d cross product), and so on. These functions are very helpful for navmesh creation and navigation, checking whether an item is right/left/ahead/behind of another item and so on.
Pity I had no time to develop it further… 