Incidentally, Japan's maglev project (unlike their ordinary trains) is being done at ridiculous costs and ridiculous timeframes ($80 billion USD spent over 31 years -- 2014-2045 see https://en.wikipedia.org/wiki/Ch%C5%AB%C5%8D_Shinkansen). Seems like the technology is very tricky and 90% of it will have to be built in tunnel.

They can support this because their ordinary transit infrastructure is built out already, the Tokaido high-speed line is at capacity (trains every 5 minutes at peak hours)! Effectively, they have the money and they've run out of more reasonably scaled infrastructure projects to build.