[VladRussian2]

>I am unconvinced by "The Europeans[..]did not adapt and subsequently lost the option of smooth land transportation for almost one thousand years."

>By the subsequent text, "Roman road infrastructure remained relatively useful until about the 11th century AD" and they started building them again in the late middle age. The middle ages by definition in the 15th century so the 11th is already near the late middle age.

it isn't that Roman roads disappeared as physical artefacts - they are still there. It is the long-distance trade using this roads under protection of unified Roman Empire stopped. Similarly like long distance trade blooming under Mongol Empire (without any noticeable road infrastructure) had decreased significantly with Mongol Empire breaking up.