Yeah, let's build them! Let's take your knowledge of building roads, my knowledge of building roads, and combined, I'm willing to bet that we'll have a total of zero knowledge of how to build roads. Since we can't do it, someone will have to. But that someone is going to want to be paid for their investment/hard work, so you'll probably have to pay tolls every few miles. Oh, wait, some people can't afford those tolls. Those people better stay home or get ready to walk it, because they're fucked.
The same logic can be applied to pretty much everything else. It's a good society...for those who can afford it. But hey, at least we don't need those poor deadbeats mooching off our roads and having police protection and shit. That's reserved for the people who deserve it. That's for the people with wealth.
Dreams and reality rarely intersect.
The above would be perfect. I would love for all roads to be build by private organizations and them charging toll. If you don't want to or cannot pay you have no business using the road. Of course this is only one of the government solutions.
I would love to live in a government-less society. We will get there the long way around by slowly eroding the governments away until there is nothing left.
Governments often sponsor toll roads. It's not like toll roads vs. freeways are an example of government vs. private infrastructure development. And it's not like people are paying less because they do it through taxes. And I'm not even sure anyone is saying that they specifically want to stop having highway departments, although I suppose there might be someone. In a totally free market, people would make toll roads when the deemed it competitively profitable. They would compete with other routes, and with other modes of transportation, such as rail. Things would be priced on supply and demand, which would be more efficient than taxation and patronage. But getting land for roads would be hard without eminent domain. I don't see highway departments going away, even if all highways are privately operated. And when an operator goes bankrupt, the state will be there to manage the bankruptcy. Unless you have private arbitration for bankruptcies. All these things will inevitably work out no matter how they are organized, because people want to travel. If you can provide a way for poor people to travel, you will get their business, and their money. This is true regardless of the role of the state. If Eisenhower never built the national defense highway system, we might have cross-country bullet trains today. Who can say? Market opportunities were lost, certainly. Others were created. Poor people still can't travel unless they can get a ride. On toll roads, they would probably pool, use a bus, something efficient. Freeways create a lot of social damage too.