The Surprisingly Vast Reach of the Ancient Roman Road Network

At the height of its power in the second century A.D., the Roman Empire was the largest the world had ever known. More than 55 million people lived within its borders, stretching from modern-day Britain, Spain and Germany to northern Africa, the Middle East and Asia Minor. The Roman Empire reached its greatest extent in A.D. 117 under Emperor Trajan, who ruled over a territory of nearly 2 million square miles.  

Even more remarkable than its sheer size, however, was that each far-flung province of the Roman Empire was connected by a vast network of roads.  

“Rome was the first example of a continental-scale, integrated empire,” says Tom Brughmans, an archaeology professor at Aarhus University in Denmark. Yes, places like ancient Britain and Egypt had roads before they were swallowed up by the empire, says Brughmans, “but the Romans were the first to really connect all these local road systems so you get this massive connected terrestrial infrastructure system for the first time in human history.” 

Roman roads have fascinated archaeologists and historians for centuries, but most of the attention has gone to grand stone-paved roads like the Via Appia or Via Augusta, which functioned as the “highways” of the ancient world.  

But according to research published in November 2025 by Brughmans and his colleagues in Spain, the full extent of the Roman road network went far beyond those major thoroughfares. By cross-referencing archaeological and historical records with topographic maps and satellite imagery, the team identified more than 60,000 new miles of Roman roads, most of them unpaved secondary roads. The findings raise estimates of the extent of the Roman road network to 185,896 miles across almost 1,544,409 square miles. 

“The vast majority of roads in the Roman Empire were not those main paved, named roads,” says Brughmans, who believes that broadening the definition of Roman roads paints a fuller picture of daily life in the empire. “Roman roads are where Romans walked, and we need to find the country lanes as well as the highways.” 

The bigger Roman roads have received so much attention because they’re among the engineering marvels of the ancient world. The Via Augusta, for example, was constructed by Rome’s first emperor, Octavian (also known as Augustus), between 8 and 2 B.C. The wide, paved highway ran more than 900 miles across the length of ancient Hispania (modern Spain) from the Atlantic port city of Cadiz to the Pyrenees Mountains, where it connected to Italy.

“The Via Augusta was a huge infrastructure project that required thousands of workers to level the ground, put in different layers of gravel and paving stones, and ensure that the pavement was curved so water drained to the sides,” says Brughmans.  

Roman engineers used surveying tools like the Dioptra and the Groma to lay out orderly city grids and construct the long, mostly straight roads connecting imperial outposts. The Romans also installed milestones along major roads like the Via Augusta, each inscribed with the distance to the nearest city or way station. More than 8,000 Roman milestones have been found with Latin inscriptions.

“You see them absolutely everywhere,” says Brughmans. One of the ways that Brughmans’ team discovered new Roman roads was by mapping the geographic locations of known milestones and connecting the "dots” using satellite images and survey data.  

As impressive as they were, the main Roman roads don’t tell the full story of how people and ideas traveled across the world’s largest empire.  

“It's like trying to understand how people move around the U.S. by just looking at interstate highways,” says Brughmans. “There are tens of thousands of ancient places—villas, farms, towns, ports—where we know the Romans were. And I can tell you, all of them were connected by a road of some form or other.” 

One example comes from ancient Egypt, which became part of the Roman Empire after Octavian’s historic defeat of Mark Antony and Cleopatra in 30 B.C. Egypt is mostly desert, so it didn't make sense for the Romans to haul tons of gravel and stone to construct paved roads over vast expanses of sand.  

Instead, the Romans took existing desert trade routes—some consisting of nothing more than wide camel paths—and incorporated them into their network of imperial roads.  

“In a desert, a ‘Roman road’ is a wide lane, perhaps with some milestones along the side,” says Brughmans. “They also constructed way stations—Roman forts where travelers could replenish their supplies, exchange their camel or take shelter from a sandstorm.”  

If a “Roman road” is any road used by Roman citizens, then that definition includes everything from a paved two-lane road passing through a major city to a dirt path winding through an olive grove. Brughmans hopes other scholars will use the digital atlas of ancient Roman roads to explore how this unprecedented physical network changed history.   

The second century A.D. was precisely the time when early Christianity spread throughout the Roman Empire. The new religion traveled with missionaries along this network of Roman roads. It was also when mass migrations of Germanic peoples entered the Western Roman Empire and ultimately contributed to its fall.  

“These Roman roads—both paved and unpaved—gave structure to massive cultural shifts that affected Western history for the next 2,000 years,” says Brughmans.