Yes, that's correct Bilbo ... but if the AI is enabled, I use the 'Build in pause mode' cheat to stop it bulldozing my work.
The other requirement with AI players is that road service-depots have to be next to a station, otherwise they nearly always get demolished by the AI ... not every time mind you, but nearly every time.
The set-up below is perfect for managing eight companies ...
- Set Number of competitors to 7
Disable road for AI
Disable rail for AI
Disable ships for AI
Disable aircraft for AI
Always place road depots next to stations
This way, the AI doesn't seem to affect the game at all ... it certainly doesn't do any terraforming, I haven't even caught it removing vehicles!