Yes, the AI are "Artificial Idiots". The reason is that they actually just move on a "wire" and just can move forward and backward. So to let those stupid guys go past you'd actually have to stop on the left side (which will then stop the AIs coming in the other direction).
Thank you very much for your feedback. And a video, great!
(I hope you don't mind if I link it here...)
Edit: Ok, saw in your video how the AI ships are "merging" in the Froncysyllte Basin. Maybe this'll get a bit polished until the release but I doubt that they act much smarter.
Michael