[PaulDavisThe1st]

Let's combine two things:

1. the observation that, AFAIK, there are no instances anywhere in the world where adding roads or lanes to roads resulted in over-capacity for the roads

2. your claim that this is because of existing demand that was not previously being met

This would appear to imply that the existing demand - which I'd like to call "implicit demand", because it was not visible via behavior until the roads were expanded - is in fact so large that to meet it would require building a road system of so vast a scope that we clearly would not want it.

Put differently, if building roads merely exposes existing demands, and the 10-100x fold increase in roads over the last, say, century, has not yet met those demands, then we should conclude that it is either impossible to meet those existing demands or will require basically the total destruction of so much land that it will be untenable.