At Canary Wharf and the ticket barriers and escalators are deliberately kept closed or are going in the "wrong" direction to prevent the platforms from being to

At Canary Wharf and the ticket barriers and escalators are deliberately kept closed or are going in the "wrong" direction to prevent the platforms from being too full. This way there is room to get off the train even at 6pm when there are a thousand people waiting to get in the train.