I remember that I like bully the AI when is slowly building a railway or road. I think that I like to do, was putting a depot with a cheap train and a railway crossing his road. So I stop the train on the road and it become blocked. or make the train to collide the bus/truck...
What I used to do with the AI is when it starts running a bus route you can lead the buses into your own road, then cut it off. Then the buses will just drive around in a circle forever, constantly breaking down because they never get to the depot.
