A study recently published by Scientific Data unveils Itiner-e, the most complete digital reconstruction of the Roman Empire’s land routes. An international team led by archaeologists Tom Brughmans of Aarhus University and Pau de Soto of the Universitat Autònoma de Barcelona stitched together 14,769 road segments that covered 299,171 kilometers across nearly four million square kilometers.
“It has come from a huge frustration. It’s the most puzzling subject in Roman archaeology… So why can’t I download all Roman roads?” said Brughmans, the project’s principal researcher. His team drew on archaeological reports, ancient itineraries, modern and historical maps, satellite imagery, and Cold War spy photographs.
Their work overturned the long-accepted figure of 188,555 kilometers for the imperial network. The new total rose by 59 percent to 299,171 kilometers—“more than seven times the circumference of the Earth,” said Brughmans, according to National Geographic Historia. About 103,000 kilometers were major highways such as the Via Appia, while 195,000 kilometers were secondary or rural tracks that kept local traffic moving.
Every stretch in the database carries a unique identifier, its source, and a certainty rating. Only 2.7 percent of the alignments were confirmed archaeologically, 89.8 percent were mapped with lower accuracy, and 7.4 percent remained hypothetical. Those figures meant just 8,000 kilometers could be located within 50 meters in mountains and 200 meters on plains. “Although the Itiner-e does not show changes over time, it is a solid foundation for future investigations on the evolution of the Roman road network,” the authors wrote, according to SAPO.
Digital tools let the researchers refine earlier straight-line guesses. “In the projects carried out until now, there has been a tendency to estimate straight alignments. By specifying the alignments of the routes previously proposed and adapting them to the terrain’s relief, the distances have increased. In passes like those of the Pyrenees, the roads could not be straight,” explained de Soto in El Diario Montas. Adjustments to valleys, mountain passes, and river courses even revealed roads now submerged beneath modern reservoirs.
Contrary to popular belief, the densest road hubs appeared in the Po Valley and Alpine corridors rather than in Rome itself; only when sea and river routes were included did Rome become the true center of the network.
The database also holds travel‐time experiments. One simulation clocked an ox-cart journey from Utrecht to Rome, while another measured a foot march from Nijmegen to Cologne. A pedestrian trip from Salmantica to Comum would have required about 447 hours at 4 kilometers per hour. Standard speeds—4 km/h for walkers, 2 km/h for oxen, 4.5 km/h for pack animals, and 6 km/h for mounted couriers—let scholars model everything from mail delivery to military response.
Itiner-e is freely available at itiner-e.org, where users can inspect gradients, preservation states, and route certainty. “This is not a closed project, but a living tool,” said de Soto. “Three hundred thousand kilometers is really just the tip of the iceberg, and we hope to stimulate future work to improve open knowledge of the locations of all Roman roads,” added Brughmans.
Funded by Denmark’s Danmarks Frie Forskningsfond through a Sapere Aude leadership grant, the open platform is expected to support studies on mobility, trade, administration, migration, and disease transmission. It already exposes blank spots in regions such as Germany, Denmark, Poland, and Ukraine, where roads remain undocumented and likely reflect areas controlled by Germanic tribes.
Roman engineering also received renewed attention. Many roads lay on multilayered foundations up to two meters deep, carried drainage, bridges, and milestones, and some, like those in Timgad, even accommodated two-lane carriageways where traffic kept to the right. With 55 million inhabitants relying on fast troop movements, tax collection, and grain shipments in the second century CE, the empire’s highway web dwarfed any modern counterpart—and much of it still guides the routes beneath today’s asphalt.
Written with the help of a news-analysis system.