Curious question: Why not keep the door open until the train start to go?

[RobbyNie]

I have stayed in Zurich for a few weeks, and notice a curious thing: The train's door will close for a while before the train start to go, during this period, people can click a button to open the door.  From design perspective, why not keep the door open until the train go? what is the advantage of this design? 

Thanks.

[SandraI · Accepted solution]

Hi RobbyNie

All doors are protected with light barriers and contact loops. When the train stops at the station, the locomotive driver allows the doors to be opened. As long as the light barriers are interrupted by passenger movements, the doors stays open. If no movement is detected, the doors close automatically after a few seconds.

I personally don’t understand the advantage of letting doors open longer than necessary (no offence). Depending on the wheather conditions, it could be uncomfortably draughty.

Kind regards
SandraI

[RobbyNie]

Hi, Sandral

Thank you so much. Your answer makes sense to me.