Please report dangerous drivers to the police - Roadsafe. Report to plod, not just whinge here.

... But I can't think of any other situation when can you just stroll up to the front of a queue just because...

If you're on a scooter or a motorbike you can often filter to the front. I don't think most people in cars care that much about being filtered past like that, since it doesn't really effect them. I know that's true of me when I drive.

What's annoying is being prevented from going fast, whether it's a tractor, a milkfloat, peds, cyclists or other slow-moving cars. Traffic means unhappy driver.