Future Singapore MRT?

I recently presented my Geography ACE on Singapore's transport.  According to Newsweek, Singapore has one of the best infrastructures in the world.  As for transport infrastructure, the main form of public transport is buses currently, but the government wants to make the main form of public transport the MRT in 20 years time.  The MRT is not slowed by large crowds unlike buses, and the MRT is much faster than even cars.  As such, Singapore's MRT system is set to be doubled by 2020, and quadruple to 540km in 2030 – that's 130km longer than the London Underground!  This is a speculative Singapore MRT map that I found on the web.