Hyperloop.
I'm really not anti-technology. OK, maybe I'm a bit more grumpy and skeptical in my older age, but I just see how shiny new ideas that don't actually work yet are used an excuse to not invest in things that do work in an era where not investing in such things is a problem.
And one thing I see with shiny new technologies is that their proponents ignore cost issues which aren't actually much different than the cost (money and time when we're talking about transportation technologies) issues faced by existing workable "conventional" technologies. Maglev proponents (yes, maglev is actually a real technology that works, but we don't have any of it in this country or people who understand it*), for example, tend to ignore the costs of land acquisition for rights of ways, cost of tunneling, and costs of station construction in expensive urban areas, those same costly items which make conventional or HSR also quite expensive to build. That doesn't mean Maglev is bad, it just means if you assume away all the costs it comes out looking a lot better than it should.
And the new freight focus of Hyperloop shows it's a cool idea looking for a problem to solve. Hyperloop sounds really cool! That doesn't mean it's workable or useful enough to justify the costs.
*Just as an aside, for years there was a "plan" to build a Maglev from the Pittsburgh airport to downtown Pittsburgh. This is a distance (about 20 miles IIRC) over which Maglev would be completely pointless. They take 3-5 miles to accelerate fully. You could build a fast rail system for much less money, which would also interoperable with existing rail, which would be in practice just as fast. People who wouldn't want to spend money on a "train" were dying to spend money on the maglev, because maglev is cool. Needless to say it was never built.
