Request to open the doors
On most vehicles, you control the opening of the doors: either by pulling handles on the doors (metro), or by pressing the green button on the green strip in the middle of the door.
Inside trams and buses, indicate to the driver that you will be getting off at the next stop by pressing the blue button. The light above the doors indicates that your request has been registered. The doors will open automatically at the stop. Although they close automatically, the driver checks if everybody has boarded or alighted from the vehicle before he leaves. Warning: The red buttons are alarm signals, and their misuse is punishable by law.