… is from page 194 of Deirdre McCloskey’s and Alberto Mingardi’s excellent 2020 book, The Myth of the Entrepreneurial State (footnotes deleted; links added):
The Good Roads movement in the US in the 1920s, for example, was meant, as its motto had it, to “get us out of the mud.” The “us” had recently acquired autos, and were therefore eager to persuade local and state governments to make, for their benefit but often not at their cost, new roads paved with concrete or asphalt. Suppliers of concrete and asphalt also had opinions on the matter, and bribed county commissioners to express their opinions. But paved roads of course can be privately offered. Many roads in the 18th and 19th centuries were in fact private, “turnpike” roads paved with logs or with “macadamized” surfaces. They can now be re-privatized easily, as parking in Chicago has recently been, considering the cheap technology of transponders and the internet. It allows a company to charge for your presence on its road or parking space. In 1924 the economist Frank Knight showed that such a company would be led by self-interest to charge the price that controls congestion to the socially correct degree. No surprise there: it’s the latent function of prices.