Bus adverts are just one form of out-of-home (aka OOH) advertising which does pretty much what it says on the tin: it’s advertising that reaches people while they’re out and about outside of their homes.
Play off of the fact that it’s a bus—warp peoples’ perspective of what they think they know they’re looking at. We use the doors, wheels, lights, even the passengers inside the windows to be playful with the creative.
This is how to make a bus look like something it’s not!