passenger entrance; boarding gate
Refers to the designated entrance for passengers at a train station or similar transport hub.
My ticket was checked at the station's passenger entrance.
passenger door
Refers to the door through which passengers board a train, bus, or similar vehicle.
The bus's passenger door is the front door.
I lined up at the boarding entrance on the platform and waited for the train.
Please board the bus through the front passenger door.
The passenger door closed just before departure.