Elon Musk's new idea of tunnels below the city is fascinating. I think a lot of people make fun of him but respect for someone who tries to find a solution and not only on paper. This is the video he showed during his TED Talk in Vancouver.
In Amsterdam that would be a problem, Amsterdam is build on poles. We have a metro 'system' that has cost too much money already, one metro, going from South to North, the North-South line. I refuse to use this one. Why? First the money it has cost us, second safety, third the damage it did to beautiful old buildings already.
But back to Elon Musk. I like the way he doesn't sit on the couch and complain but tries to work on a solution. Take a look at this video.