Originally Posted by
yosithezet
This is really interesting! In all these years, I've never experienced it, but it makes sense.
I've experienced this most often inbound from Surasak on the Silom line, in the late afternoon. Savvy commuters drift to the right-side doors for a quick exit. But if the train crosses over (no longer going to National Stadium, but rather Mo Chit) after Ratchadamri, the doors will open on the left.
But they do make announcements, in Thai and English, both about the change and on which side the doors will open.