Google Maps for the ancient world The Romans built many more roads than previously thought
Busy roads were often paved, as in the ancient city of Timgad in Algeria
Image: -/tiner-e, Artas Media, MINERVA/dpa
The map shows the extent of the road network in the Roman Empire
Image: dpa
The illustration shows a kilometer stone on a mountain road in Cilicia, Turkey
Image: dpa
Fragment of a Roman kilometer stone on the Via Nova in Jordan.
Image: Adam Pažout/Itiner-e/dpa
Busy roads were often paved, as in the ancient city of Timgad in Algeria
Image: -/tiner-e, Artas Media, MINERVA/dpa
The map shows the extent of the road network in the Roman Empire
Image: dpa
The illustration shows a kilometer stone on a mountain road in Cilicia, Turkey
Image: dpa
Fragment of a Roman kilometer stone on the Via Nova in Jordan.
Image: Adam Pažout/Itiner-e/dpa
The Roman Empire stretched across three continents. The road network was much larger than previously assumed. Reconstruction proved difficult.
06.11.2025, 22:31
07.11.2025, 07:32
dpa
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- The Roman road network was much larger than previously assumed.
- This is shown by an international study in the specialist journal "Scientific Data". According to the study, the road network was around 100,000 kilometers longer than previously assumed.
- The roads connected an empire that stretched across three continents and was home to more than 55 million people.
- The research team also presented an online, high-resolution map that can even be used to calculate routes.
All roads lead to Rome - and there were far more than previously assumed. A study in the journal "Scientific Data" shows: The Roman Empire's road network was around 100,000 kilometers longer than previously assumed. At the height of Rome's power, around 2,000 years ago, these roads connected an empire that stretched across three continents and was home to more than 55 million people.
"We present the most detailed and largest open digital dataset on roads in the entire Roman Empire," writes the team led by study author Tom Brughmans from Aarhus University in Denmark. The research group presented a high-resolution map that is much more precise than previous measurements and can be accessed online: basically like Google Maps for the ancient world. Even routes can be calculated.
The international team examined data from around 40 countries. "The resulting map covers a total of 299,171.31 kilometers of roads over an area of around four million square kilometers," it says.
Routes were adapted to geographical reality
Roads were already of enormous importance back then and formed a foundation of Roman power: they connected provinces from the Atlantic to the Euphrates and facilitated the rapid movement of troops as well as the exchange of goods and ideas. Some of them - including the Via Appia in Rome or the Via Egnatia through Greece and the Balkans - are still visible today or in some cases even form the basis for modern transportation routes.
Despite this, the road network in the Roman Empire was previously recorded in a rather fragmentary way. The new map now shows the reconstructed road network for Italy, North Africa, the Near East and Germania. The main roads - known as viae publicae - account for around 34 percent, i.e. around 100,000 kilometers. Secondary roads make up just under two thirds, around 195,000 kilometers.
The researchers explain the fact that significantly more kilometers have now been counted than in previous studies: "Above all, the routes have been adapted to the geographical reality." To cross a mountain, for example, the roads follow a winding pass road rather than a direct line.
Difficult to reconstruct the exact course of the roads
But how do you even find out where roads ran around 2,000 years ago? To find out, the team first looked through the relevant literature and identified roads based on historical and archaeological sources, gazetteers and other landmarks such as rivers and settlements.
They then focused on modern aerial and satellite imagery to better reconstruct the possible course of the roads, taking into account the shape of the landscape. In the final step, the data was then digitized.
"In many regions, such as northern Italy or Tunisia, the Roman land divisions, which also included the construction of roads, have often been preserved in the modern road network," writes the group. Smaller roads in particular are important evidence of ancient Roman roads. Modern highways and expressways, on the other hand, rarely correspond to historical roads.
Nevertheless, it was difficult to reconstruct the exact course of the roads: For the vast majority, around 90 percent of the routes, the exact course is not known, and for around seven percent it is even only a matter of conjecture.
A lot of information can be derived from the road network
The researchers are only really sure about just under three percent. An important fact that the team also makes transparent in the map that has now been published: "We know that all the roads included in our map were used at some point during the Roman period, but their exact location is not certain," they say.
"A major challenge is the lack of chronological evidence for the creation and change of roads. We know that transportation networks grow organically, new roads are built on old roads, they change their function and some are no longer used at some point."
Detailed chronological evidence for the construction, use and change of roads was therefore only available for a few cases. "An evidence-based reconstruction of the changes in the road network during the entire Roman period at the imperial level is currently not possible," the group writes.
The scientists see potential for further research here, as a lot of other information can be gleaned from the course of the road networks. For example, the spread of diseases along trade routes or economic networks. And modern traffic planning can also benefit: Comparisons between ancient pass roads and today's routes often show astonishing similarities in optimal terrain courses through mountains or river valleys.
