Don't forget Australia. We have a few, large cities separated by long distances. In particular, Melbourne to Sydney is one of the highest traffic air routes in the world, roughly the same distance as the proposed Hyperloop, and there has been on and off talk of high speed rail links. Additionally, Sydney airport has a curfew, and is more or less operating at capacity. Offloading Melbourne-bound passengers to a cheaper, faster option would free up more flights for other destinations.