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The old saying that “all roads lead to Rome” has inspired countless maps and metaphors. Now researchers have built a digital atlas that makes that idea tangible—letting users trace the empire’s highways and byways with a level of detail previously unavailable.
Named Itiner-e, the interactive project plots the routes that would have existed across the Roman world around 150 CE. Created by a multinational team of scholars, archaeologists, and geospatial experts, the atlas functions much like a historical version of Google Maps—showing main arteries, secondary links, and probable tracks that crisscrossed an empire that spanned continents.
Inside Itiner-e: a modern map of ancient Roman roads
A collaborative network of roughly two dozen specialists from across Europe assembled Itiner-e from a diverse body of evidence: archaeological excavation reports, ancient itineraries and texts, high-resolution topographic maps, and satellite imagery. The goal was to move beyond low-resolution digitizations and produce a navigable, research-grade road atlas for the Roman imperial period.
Rather than drawing straight lines between known settlements, the team modeled routes to follow realistic terrain constraints—allowing mountain passes, river crossings, and coastal contours to shape the pathways. The resulting resource includes many features familiar to contemporary map users, such as layered road types and searchable place names.
How big was Rome’s road network? New numbers and regions
Earlier estimates placed the Roman highway network at roughly 117,000 miles. Itiner-e expands that figure dramatically: the dataset now documents nearly 180,000 miles of roads spread across more than 1 million square miles. Much of the added mileage comes from fresh mapping work in:
- Iberian Peninsula (modern Spain and Portugal)
- Greece and the Aegean region
- North Africa, including former Roman provinces in today’s Morocco, Algeria, and Tunisia
At its second-century peak, the empire governed an estimated 55 million people and stretched from Britain in the north to Morocco in the south, from the Atlantic to the Syrian desert in the east, and eastward across Anatolia. The road system was the skeleton that held this patchwork of provinces together.
What the map says about certainty and reconstruction
Not every segment of road can be pinpointed with equal confidence. The Itiner-e team categorized the network by the degree of evidence supporting each segment:
- 2.7% of routes are located with high confidence based on surviving remains or unambiguous records.
- 89.8% are mapped with lower precision—likely courses inferred from topography, fragmentary finds, or historical sources.
- 7.4% remain hypothetical, representing scholarly proposals where direct evidence is scarce.
These classifications make Itiner-e not just a visualization tool but a research framework: users can see which stretches are firmly attested, which are best guesses, and where further investigation could improve the map.
A traveler’s route: from Roman Salmantica to Comum
The atlas also allows historians and curious users to reconstruct ancient journeys. For instance, a route plotted from the Iberian city of Salmantica (modern Salamanca) to the vicinity of Comum (near modern Como, Italy) highlights how connectivity worked over long distances.
Key legs along this corridor include:
- Eastward across Hispania to Pompelo (now Pamplona).
- Over the Pyrenees along a main highway, then turning onto a secondary road toward Elusa in southern Gaul.
- Rejoining a major eastbound route past Tolosa (Toulouse) and skirting the Mediterranean by Nemausus (Nîmes).
- Descending through Alpine passes via secondary roads to Cuneo, then on to Augusta Taurinorum (Turin) and Novaria (Novara).
- Crossing the River Ticino and leaving the main route via a smaller Roman track to reach Comum and nearby Vergiate.
On Roman roads the journey would be slow by modern standards but steady: Itiner-e estimates roughly 447 hours of travel time for that trek, assuming an average walking pace of about 2.4 miles per hour on well-maintained surfaces.
How Roman engineers built roads that lasted
The durability of many Roman routes stems from the layered, engineered approach to construction. Typical elements included:
- A fossa, a trench excavated down to bedrock or firm ground to establish a stable foundation.
- Fills of rubble, gravel, or compacted material to lock into and level the substrate.
- Successive layers of native soil, sand (when available), and tamped gravel for structural depth.
- A binding layer—often a lime-based concrete—into which paving stones were carefully fitted, forming a robust wearing surface.
Roadways were usually crowned in the center to encourage runoff, a drainage technique still used on modern highways. In some Roman settlements—Timgad in Algeria is a notable example—streets functioned like multi-lane roads and even featured signage and distance markers along secondary routes. Archaeological evidence suggests many regional roads were intended to minimize maintenance by relying on sound materials and intelligent design.
Methods, technology, and the interdisciplinary push
Itiner-e demonstrates how contemporary tools can reshape our picture of the past. The project combines:
- Field archaeology and historical texts for ground-truthing
- Topographic and geological mapping to model likely corridors
- Remote sensing and satellite imagery to spot linear features and landscape modifications
- GIS and spatial analysis to stitch diverse sources into a coherent, scalable atlas
By integrating these approaches, the team could refine previously proposed alignments—adjusting routes to follow plausible mountain switchbacks, valley floors, and river fords rather than drawing unrealistic straight lines.
Open questions and the road ahead for research
Even with Itiner-e’s expanded coverage, large swaths of the Roman transport network remain imperfectly documented. The atlas points researchers toward regions where new fieldwork, remote sensing surveys, or digitization of archival records could substantially reduce uncertainty.
As digital mapping tools continue to evolve, projects like Itiner-e bridge scholarly inquiry and public curiosity—making it possible to explore the infrastructure that underpinned one of history’s largest empires in a way that’s both rigorous and accessible.
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Michael Thompson is an experienced journalist covering U.S. and global news. With ten years on the front lines, he breaks down political and economic stories that matter. His precise writing and keen attention to detail help you grasp the real‑world impact of every event.
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