Oh god, the porous glass bridges.

So, Walter Block is a Libertarian economist with some pretty serious sounding credentials. Chair of economics at Loyola University, New Orleans, Senior fellow at the Ludwig Van Mises institute... Like, this guy isn't a crank with a blog. He gets paid, and published.

And he wrote what is, among Libertarians, considered the seminal work on the privatization of roads and highways, a book called, no surprise, The Privatization of Roads and Highways.

Privatizing roads is a really funny gotcha to throw at any Libertarian you meet, because it's basically an unsolvable problem. How do you have fair and free market competition for getting out of your driveway? Ask the average Libertarian about it and they'll panic. Ask a Libertarian who's been around other Libertarians long enough, and they'll more likely retort by telling you to go read Walter Block's book.

Now, I want to be clear; none of these people have actually read Block. It's just an easy way to dismiss the question, because the average leftist isn't going to read an entire textbook just to prove you wrong. But the reason I know they haven't read Block is because I did, and everything he wrote is objectively insane.

The majority of the book is basically just an argument for why we should privatize roads (his argument is "Accidents will go down", his source is "I made it up."), but in the last third he addresses criticisms of his previous work on the subject, and in doing so is forced to address the practicalities. This is where Walter Block stumbles into an entire Battle City of trap cards. It's... A long road (ba-dum, pssh) and someone like Dan Olsen could get an easy two hours out of the layers of insanity happening here, but basically Block ends up acknowledging that;

• It would probably be really bad if land ownership extended into the sky, because then a few land owners might be able to basically encircle a city and prevent any roads going in and out. So you need to be allowed to build over other people's land. Not on it, but, you know... Bridges. Unsupported miles long bridges.
• It would probably be really bad if land ownership didn't extend into the sky because then you could just build a bridge over someone's farm and block all their sunlight and rainwater. Wait, no, that contradicts the previous point.
• OK, you're allowed to build over other people's land but everyone has a right to sunlight and rain so your bridge has to be transparent and porous. A glass bridge, full of holes for rainwater to sluice through. All the cars on it definitely won't block any sunlight. They'll, um, probably be made of glass too.
• Cities are a problem because you can't just build a road next to someone else's road. Because there are buildings there. No problem, just build on top of them. We've already established that building over other people's property is OK. Why, you could probably have four or five companies all competing for your drive to the shops. Imagine it; four elevated highways stacked up over a street level road with the most insane corkscrew onramps feeding them.
• OK, there should probably be some rule about how close you can build to the people below you. A hundred feet sounds about right to Walter.

So now we have our inevitable outcome. The Libertarian answer to the question of competition in a market space where competition is functionally impossible; a quintuple decker porous glass highway extending 500 feet into the sky, each part of it built and maintained by a competing company, with no safety standards other than "You can sue someone if you die."

This man is, I cannot emphasize this enough, considered to be a serious Libertarian economist, and Libertarian influencers cite his book as the treatise on this subject.