It would make the AI traffic more realistic for AI buses to stop at bus stops. There would be buses that drive different lines, and the doors would open.
AI bus routes would be fairly easy to make if a decal road could be tagged as "bus line" (or something vehicle specific), so that only those vehicles could spawn and drive on it and ignore all other paths. I tested a quickly made 101 Norte bus route, oneway looped road with wide curves and AI can handle a bus through it without damage or getting lost (I deleted nearby AI roads). I don't know if it's possible to make "stop & go" triggers for AI yet.
Doesn't need to follow a specific route, just stop at a bus stop, open doors for a while, close and drive again. There could be some LUA stuff added for it to work.
I think they need very detailed routes indeed. Now they just cause mayhem getting stuck on paths not very suitable for them.
I think it would need to be an option in the AI menu, for example, "detailed AI paths"; that way it could be turned off. It should also be a probability that way all the busses on the map don't cram into a bus stop. So they would only stop every few times. But it's a good idea