A popular socialist contention against people who want a lesser government (eg libertarians) and anarchists is: "Who will build the roads?" implying mainly that it is ONLY government that can build roads and thus government is necessary. The question seems comical yet holds a philosophical essence as to the nature and role of government in society.
A simple answer to this is: "Who built the first foot tracks during the early times?". Certainly not government but people out of the natural necessity to do so.
But why early people did not build roads during those times? The answer is that there is no reason for them to build something that is not yet required by the need to have it. Technology and roads go together. When technology advances, the roads gets wider because it is necessary to be so. The invention of wheels made foot tracks to be widened. The invention of cars need widened foot tracks to be paved.
So who will build roads? The answer is those who feel there is a need for it.