This is a real feature of the underground I strangely miss. A crowd of people walking along a small tunnel around 12 meters side and meeting a crowd of people

This is a real feature of the underground I strangely miss. A crowd of people walking along a small tunnel around 12 meters side and meeting a crowd of people walking in the opposing direction. There is no pause, no slowing down, no acknowledgement, it just happens, like ghosts passing through each other, no one makes contact.