Civil engineers have looked at the Hyperloop proposal and declared themselves unable to determine how Musk proposes to reduce the costs of long runs of overpass, or of tunneling.
A simpler way to make the same argument:
If Musk can actually build a Hyperloop across California at his proposed cost, he's made revolutionary improvements to civil engineering that will be far more impactful than the Hyperloop itself; the same techniques should revolutionize, well, much of conventional civil engineering! Why isn't that happening?
