[tet68]

standing side-by-side on escalators, blocking the left-hand fast lane,

I didn’t realize there WERE lanes on escalators,
you’d think the DOPT would mark them.
( Dept of Pedestrian Transportation )

[ETL]

I didn’t realize there WERE lanes on escalators,

There aren't. It's more of a common sense, common courtesy thing. I can understand some tourists not getting it, but not those that lived here awhile.