You drive a bus. You realise that right?
On that basis if a plane is a flying bus, then a truck is passenger-less bus, a train is a long articulated bus on rails, a taxi is a compact bus, a ship is a floating bus, the space shuttle is a space bus, a tank is a war bus and a helicopter is an incredibly noisy complicated bus.
Now which bus uniform should we wear, the shorts and short sleeve with epaulet town bus, the interstate suited coach captain, the minibus slacks and corporate shirt tour jockey or casual smart airport bus checked shirt, or the pub bus jeans and collared shirt with some beer logo on it. I'm think the ideal uniform might be from the passenger-less 18 wheel bus, blue stubbies and tank top (with pie stains).