Abstract: A one-way passage system (1) comprises an entrance door arrangement (2a) and offset therefrom an exit door arrangement (2b). First and second side wall arrangements (3a, 3b) are provided therebetween, thereby defining a passage area (4). A sensor device (5) can detect persons (10): a) before the entrance door arrangement (2a); b) in the passage area (4) and/or after the exit door arrangement (2b). A control device is configured to enter a safety operating mode and to close the entrance door arrangement (2a) when an analysis of sensor data indicates that a person (10): a) in the passage area (4) goes back in the direction of the entrance door arrangement (2a); and/or b) goes back after the exit door arrangement (2b) in the direction of the passage area (4). An illumination device (20), which is arranged in the passage area (4) can illuminate the passage area in different colors.