The roads of the Roman Empire were not as straight as popular tradition suggests, nor did Rome necessarily occupy the most central position in the empire’s extensive transport network. This is revealed by a structural analysis of nearly 300,000 kilometres of Roman roads, published in the journal Nature Communications.
At its height, in AD 117, the Roman Empire stretched over about 5.5 million square kilometres, encompassing territories in Europe, the Middle East and North Africa. This area was linked by a combination of roads, rivers and sea routes.
Tom Brughmans and colleagues analysed the characteristics of the Roman road network using the digital Itiner-e model, which gathers topographic information from nearly 300,000 kilometres of roads. The team evaluated four characteristics of the landscape and the roads: average and maximum slope, altitude, orientation and degree of road linearity.
The results show that the Roman roads were predominantly straight when terrain conditions permitted it, especially in low-lying regions, such as parts of Western Europe and North Africa. Yet, they were, in general, less linear than modern paved roads, due to technological limitations and the characteristics of the terrain.
Rome was not the center of the entire network
The investigation also questions the idea that Rome occupied a central position in the empire’s entire road network. Some important cities, especially provincial capitals, acted as major local crossroads and exhibited a more central position in the network than other cities.
Antioch, Ankara, and Byzantium are among the examples identified by the researchers as cities that showed a more central location in the road network than Rome.
The study also shows that there is no region where the Roman roads wholly determine the current road infrastructure. However, the growth in the density of modern roads is particularly evident around former population centers that have nevertheless transformed into large metropolitan areas, such as Birmingham, Madrid, and Paris.
The researchers also suggest that the construction of roads was planned largely at the provincial scale, rather than arising from a single centralized strategy for the entire empire.
The network analysed, however, does not include all Roman transport infrastructure. The available data have gaps, and the authors argue that future investigations should also integrate river and maritime connections.
Understanding the organization of these networks could help study how people, goods, ideas, and diseases circulated through the Roman Empire, as well as the influence this infrastructure had on the organization of current transportation networks.
