Cities define transportation which define other cities.
“The impact of these sorts of roads can actually be observed archaeologically, because they tend to come quite late historically and thus alter pre-existing settlement patterns, so we can see exactly how they induce population centers to shift around the landscape. J. B. Ward-Perkins did a fascinating study of this in Etruria (“Etruscan Towns, Roman Roads and Medieval Villages” in The Geographical Journal 128 (1962)). There, the Roman roads (built in the late third century B.C.) slowly alter the settlement patterns as they pull population towards them, causing old centers and villages away from the roads to shrink while new ones spring up.”
https://acoup.blog/2019/07/19/the-lonely-city-part-ii-real-cities-have-curves/