The normal situation with escalators on the tube is that the flow of people onto the escalators is less than that which would cause a queue to build up.
That is not surprising, as the system has been designed so that there is sufficient capacity on the escalators to handle the flow of people.
However, at one or two stations during rush hour the situation can be different.
Sometimes the flow of people can be such that a queue builds up.
It is debatable, though, what would happen then if people walked on both sides of the escalator.
The queue would not move twice as fast, as people will not walk on side by side.
Another problem is that people with luggage take more than one person's width.
Standing two abreast may jam up the escalator, so that people are unable to get off easily at the top.
The normal situation with escalators on the tube is that the flow of people onto the escalators is less than that which would cause a queue to build up.
That is not surprising, as the system has been designed so that there is sufficient capacity on the escalators to handle the flow of people.
However, at one or two stations during rush hour the situation can be different.
Sometimes the flow of people can be such that a queue builds up.
It is debatable, though, what would happen then if people walked on both sides of the escalator.
The queue would not move twice as fast, as people will not walk on side by side.
Another problem is that people with luggage take more than one person's width.
Standing two abreast may jam up the escalator, so that people are unable to get off easily at the top.