[RickHull]

Can't you just camber the track rather than make the trains actively tilt? I suppose the camber could be problematic at very slow speeds.

[nissehulth]

The idea was that it is much cheaper to change the trains than to rebuild existing tracks.

[tim333]

They do camber tracks but you have the problem of dealing with different train speeds. It the UK case the lines were old and not very cambered.