Putting it in California may be part of a PR idea. California needs a safe high speed mass transport system. The
HyperLoop, when finished, could be economical, safe and fast transport from northern to southern California.
The Hyperloop is a conceptual high-speed transportation system put forward by entrepreneur Elon Musk, incorporating reduced-pressure tubes in which pressurized capsules ride on a cushion of air that is driven by a combination of linear induction motors and air compressors.
This is a very futuristic design that will require a bunch of new hardware and software. Very interesting story . Thanks for posting it, Patio.
Potentially this kind of thing can reduce airplane travel and reduce California's carbon output from jet fuel. The Hyperloop would use only a fraction of fuel of a jet airplane. The test track will help engineers estimate the cost and benefit possibilities of the concept.
Here is an older story that explains the concept in more detail.
Hyperloop Explained: How Elon Musk's Futuristic Transit System Works.