I added a Bus Terminal to my city (the big kind). Later in the game, I noticed it basically disappeared leaving just a trail road and a small garage.
Annoyed, I decided to delete it and rebuild one. Except that deleting it only removed the small garage left. The small dirt road remained. I cannot delete it or build anything over it.
I tried to delete the main road next to it (hoping it will ask me if I want to delete the building too), but it didn't ask anything. Now I can't even rebuild the old roads because it says it cannot intersect the dirt road. I can't build over it for the same reason. Clicking to bulldoze doesn't do anything.