Roman Road Network Was Vastly Larger Than Previously Thought, New Map Reveals

A newly compiled digital map reveals the Roman Empire’s road system was significantly more extensive than historical estimates, potentially stretching over 68,000 miles further than previously known.

The project, dubbed Itiner-e, charts 185,896 miles (299,171 km) of roads across nearly 1.54 million square miles (4 million square km) of the Roman Empire around 150 CE. Researchers created the dataset by combining archaeological records, historical texts, topographic maps, and satellite imagery. The increased mileage comes from greater coverage in regions like the Iberian Peninsula, Greece, and North Africa, as well as more accurate depictions of roads navigating challenging terrain. This detailed understanding of Roman infrastructure offers new insights into the empire’s administration, trade, and military movements.

According to a study published today in the journal Nature, Itiner-e is “the most detailed and comprehensive open digital dataset of roads in the entire Roman Empire.” The research team notes that while the existence of these roads is confirmed, the precise location of 89.8% remains uncertain, with 7.4% being theorized. “This shows a discrepancy between our knowledge of the existence and location of Roman roads: we know all of the included roads were used at some point during the Roman period, but their precise locations are not certain,” the team explained. The Roman Empire, at its peak, encompassed over 55 million people from modern-day Britain to Egypt and Syria, and efficient transportation was crucial to its governance.

The map also reveals surprising continuities with modern infrastructure; for example, the route connecting the ancient cities of Bononia, Mutina, Parma, Placentia, and Mediolanum closely mirrors the modern road linking Bologna, Modena, Parma, Piacenza, and Milan. Researchers believe this resource will be transformative for understanding connectivity and mobility in the ancient world, and for studying the long-term development of terrestrial travel in the region – you can explore the map here.

Researchers plan to continue refining the dataset as new archaeological discoveries are made and further analysis is conducted.