This is good news: The BTS Skytrain is to take delivery of twelve new trains with, I gather, four carriages instead of three. I have often wondered why Skytrains only have three carriages when the platforms are clearly designed for much longer trains. The service really is full to capacity during peak hours, and, even in off peak it is often standing room only depending on where you get on.
I am a big fan of the Skytrain and use it as much as I can. I look forward to the day when all Skytrains will utilize all platform space.
From the Bangkok Post: http://www.bangkokpost.com/business/economics/182628/new-trains-to-help-bts