Also, the traditional Chinese wheelbarrow is an example of wheeled transport that doesn't require more than a footpath -- so, I do have doubts about the whole roads and infrastructure theory.
It was explained to me that the reason the pre-Columbians never made use of the wheel (and in many cases, never even invented it) was because their continent lacked draft animals to pull carts, so why bother.
I call BS, because those primitive, violent cultures would simply have used their pre-executed prisoners to pull the carts.
Also, the traditional Chinese wheelbarrow is an example of wheeled transport that doesn't require more than a footpath -- so, I do have doubts about the whole roads and infrastructure theory.