Hey, I know, let's spend hundreds of millions to build a miles-long 2-lane highway underground. Oh, what's that? It's literally the same fucking thing as an above ground highway except less lanes, way more of an issue if someone breaks down in it (because it's impossible to get out so you get to sit in traffic all day until they somehow get out despite there being not enough room for a tow truck), and about 10x the cost of just building another highway, or god forbid, a FUCKING SUBWAY. But noooo, we can't build a subway, this is the FUTURE! Everything has to be NEW and EXCITING and COMPLETELY FUCKING IMPRACTICAL

Hey, I know, let's build a GIANT VACUUM CHAMBER that's 10 FEET WIDE and stretches MILES and have people RIDE IN IT AT HUNDREDS OF MILES PER HOUR! BECAUSE THAT WON'T FUCKING EXPLODE INTO A MILLION PEICES THE MOMENT SOMEONE SHOOTS A HANDGUN AT IT! And we'll call it the HyperLoop!

Seriously... The guy gets some good stuff done, but he also gets some really stupid, expensive stuff done, and some stuff just ends up being an eternal work in progress, because half the stuff he does is either too stupid to be of value, or too difficult to do in the first place. Or both.