Escalators in the UK effectively have two lanes: one on the right for people who are stationary and one on the left for people who choose to walk up or down the escalator rather than just let it carry them.

There is nothing intrinsically better about standing on the right, but by establishing the convention it ensures that the left lane is always faster for people who are in more of a hurry. Think of it almost like driving on the wrong side of the road. It's not etiquette - it's survival…

In the London Underground (or "tube"), there are signs on most escalators reminding people of this simple rule.