It was so crowded at the door of the coach because when train stopped at the station, many people started getting off the train. At the same time, people who were standing on the platform started pushing the passengers and trying to put their luggage inside the train.
All this activity was done through one door at the same time. This caused the door of coach to be crowded.
A ticket checker wears a black coat and black trousers. He has a badge on his coat. He carries a list of passengers with their allotted seat number. He asks the passengers to show their tickets and also collects the fine from those who travel without ticket.