May 19, 2026

9 min read

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New map reveals lost roads of the Roman Empire

A massive digitization project has nearly doubled the known extent of the first continent-scale road network

By Tom Brughmans edited by Kate Wong

The Via Appia, constructed starting in 312 B.C.E., is the oldest and best-known road of the Roman Empire.

Stefano Valeri/Alamy

On a recent visit to Rome I walked along the Via Appia (also called the Appian Way), past the presumed house of Stoic philosopher Seneca, and felt transported in time. Constructed starting in 312 B.C.E. to carry troops southeast toward Capua and, eventually, the port city of Brindisi in the heel of Italy’s boot, the Via Appia is the oldest and best-known road of the Roman Empire.

Scholars have long regarded it as the quintessential Roman road: a straight highway extending as far as the eye can see, paved with slabs of volcanic stone, lined with pointy cypress trees and, of course, connecting to Rome. It is amazing to know that Romans walked here more than 2,300 years ago. No wonder this marvel of ancient engineering—long stretches of which remain remarkably intact today—is known as the Queen of Long-Distance Roads.

But iconic as it is, the Via Appia is not the archetype researchers have assumed it to be. My colleagues and I have produced a new map of Roman roads that, for the first time, reveals their locations at high resolution in a single, open resource. What we found revolutionized our view of the road system that undergirded this superpower of the ancient world.

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Historians and archaeologists have been studying Roman roads for centuries. In that time, they have found remnants of the roads themselves, crumbling milestones, and historical texts about major connections between settlements. But efforts to plot the roads based on these piecemeal sources yielded a low-resolution map of the Empire with approximate locations rather than precise ones.

Click on the map for a closer look. Built to transport the Roman army south to expand the Empire’s influence, the Via Appia, a portion of which is shown here, connected Rome to Brindisi on the Adriatic coast.

Daniel P. Huffman

Knowing the location of Roman roads matters for understanding how the Empire conquered and pacified new territories and transported food to keep its people alive. Their development meant that for the first time in history, an area the size of the European Union was covered by a network that allowed the flow of people, goods, ideas and disease from Egypt to Germany, Spain to Turkey. To that end, my team and I set out to build the first high-resolution digital map of the Empire’s roads, combining information from historical datasets with modern topographical maps and satellite data, among other sources. We expected that 200 years’ worth of research tradition would allow us to simply connect the data points our predecessors had collected. We were wrong.

Our research implies that in the second century C.E., the period when the Empire had its maximum extent, this road network comprised some 300,000 kilometers—nearly double the previously known total length of Roman roads. This is a massive discovery. It’s also very humbling because despite seeing the full scope of the network, we know the precise location of only 2.7 percent of it. (The preserved sections of the Via Appia are part of this well-known minority.) How, after centuries of research, can we know so little about this system? And where are the lost roads of the Roman Empire?

Let’s start with what we do know. The ancient Romans invented far fewer things than they are often credited for, and they certainly did not invent the road. Rome’s strength lay in its ability to recognize a good idea and scale it to the size of a continent.

The generals and emperors of Rome conquered regions that already possessed elaborate road systems connecting densely urbanized areas. In the east, the Hellenistic kings who succeeded Alexander the Great had built many cities, such as Antiochia, and connected them with roads just as the Persians, Assyrians and Babylonians had done before them. The Achaemenid Persians even built a “highway” between their capital in Persia, Susa, and Sardis in western Turkey, known as the Royal Road.

Click on the map for a closer look. In developing our digital atlas of Roman roads, we found 8,000 kilometers of roads whose location we know with certainty and 292,000 kilometers of roads that rely on varying degrees of conjecture. We created a confidence map that describes variation in the reliability of our sources and the accuracy of our digitization. It off