I used to tell students that someday interstate highways would be torn up and not replaced. A generation off in the future sometime would look at them and say, “What a waste of land and money.”
I can’t, of course, know that will happen but steps in that direction are happening. Some towns are letting asphalt streets and roads return to a gravel mix. Many cities are reducing four lane streets to two lane. Publicly subsidized parking ramps are coming down.
Economics explains this though we already know it instinctively. It is diminishing marginal benefits. That is, each added unit of something adds value but less than the unit before. Lots of family’s have two cars. They don’t have a third because the benefits of the third are less than the second.
Speed for airline travel was once thought very important. But, supersonic speed had diminishing marginal benefits compared to its cost so the iconic Concorde was eventually dropped from service.
There is a field of economics called “Transportation Economics.” Years ago a young professor told me transportation was so valuable it should not be subjected to the same rules of public benefit as other public expenditures. It was as laughable then as it is today. That even though politicians really like airport and highway ribbon cutting ceremonies.
Ironically, many political conservatives really like big public infrastructure projects and liberals are often skeptical. Our country simply has more infrastructure than it has money to maintain it.