2 women walking side by side with baby-trolleys on the sidewalk, when it has poured down a lot of snow, and there is nowhere to go but into the street to get past them.
Or more general: people who take up the entire sidewalk, or block passage in escalators (it should be common knowledge that you stand to the right and walk to the left)
Or more general: people who take up the entire sidewalk, or block passage in escalators (it should be common knowledge that you stand to the right and walk to the left)