Transportation networks can be regarded as an epiphenomenon of social interactions and interactions between societies and environments. At the same time, they influence the development of past societies and their complexification (e.g. emergence of urbanism). There is a feedback loop. To better understand emerging Latin and Etruscan urban polities and their interactions we modelled their terrestrial infrastructure networks to explore the underlying mechanism of their creation and maintenance. Data used to build the networks are settlements in Etruria and Latium Vetus between the beginning of the Early Iron Age and the end of the Archaic Period; and terrestrial routes hypothesized by scholars from later roads, topography and the position of existing settlements. The results of the modelling suggest that a balanced cooperative decision-making process was driving the creation and maintenance of the terrestrial route system in the Etruscan region; whereas in Latium Vetus a slightly unbalanced dynamics of power constitutes the most likely underlying mechanism. This fits very well with the picture elaborated by different scholars on the nature of power balance and dynamics in the two regions.