[lazyjones]

> If you lower the cost of something then, all things being equal, the demand rises

No. Only in abstract models with potentially infinite supply and demand. If you lower the cost of plaster casts, more people won't break their legs.

> Roads are not immune from economics, just as they are not excused from geometry.

And economics aren't immune from ideology and disingenuous modelling.

[jacques_chester]

> If you lower the cost of plaster casts, more people won't break their legs.

Now you're misunderstanding elasticity of demand and assuming that demand or supply curves are perfectly linear.

Plaster casts are highly inelastic, but if I jacked the price to $100,000 per, demand will fall off fairly sharply.

> And economics aren't immune from ideology and disingenuous modelling.

My experience is that economists know more about economics than people who beat up the strawman versions.

Your position, as I understand it, is that some other model correctly describes the demand for road travel. What is it? And why is road travel the exception?

[lazyjones]

> My experience is that economists know more about economics than people who beat up the strawman versions.

And mine is that economists disagree with each other more than with anyone else.

> Your position, as I understand it, is that some other model correctly describes the demand for road travel. What is it? And why is road travel the exception?

What model specifically are you talking about? We have N lanes going from A to B, if we add 1 lane, total traffic from A to B will increase regardless of any other circumstances? Is that it?