Unusual Scene at Bishan Station

I was at Bishan Interchange (North-South Line) this morning at around 8:45am and witness this:

Strangely, people are queuing in single line in a very orderly manner to board the trains, something rarely (maybe never) seen in SG. This photo taken shows one of the doors but the situation is basically the same on the other doors as well.

From what I understand. it happens almost every morning, not just today.

I don't know what the station staffs have done but to them, GOOD WORK! 

Hope this can be extended to the other stations as well.

Arguably, Bishan station is one of the better managed SMRT North-South line stations