I am sure that the hong kong people stop when they hear the door
closing, not because they can't go in as there is evidently no
space left.
I am also sure that people in singapore start to squeeze in
after the hearing the door closing announcement, even if there is
no space left.
All our trains and buses got ghosts. Ghosts in buses are usually
located in the back, ghosts in trains are usually located right in
the middle of any 2 doors in all cabins.