Maintaining existing roads is certainly not beyond the economic capacity of the United States. It just costs more than you're willing to pay. That's valid, but the alternatives don't appear to be cheaper. New York also finds maintaining its subways in working order, something that's certainly physically possible, to cost more than it's willing to pay.

High density and high transportation demand are prerequisites for having a public transit system at all. And what dense US city's government isn't corrupt or incompetent?