Comment by mlyle
Most roads are difficult to exclude. Most spend most of their time with excess capacity and are not rivalrous. They're clearly not a typical private good.
And they're usually a natural monopoly, too. Not to mention that the acquisition of land to make a road is often problematic.
Basically, there's a lot of reasons to expect market failure in a market for roads. That's not to say the only solution is for the government to provide them, but that laissez-faire, completely hands off solutions are probably not going to turn out great.
Nowadays it's fairly easy to exclude people from roads: just put up a sign that says you can only use them if you paid. (You can also use a camera and some machine learning to catch offenders; or otherwise cheap overseans workers who manually review footage.)
> Most [roads] spend most of their time with excess capacity and are not rivalrous.
Most cars sit around idle most of the time. I'm not sure what your argument shows?
> And they're usually a natural monopoly, too. Not to mention that the acquisition of land to make a road is often problematic.
That's a different discussion. Though I'm more optimistic.