Nearly 300,000 km of Roman Roads Mapped: Itiner-e Reveals the Empire’s Transport Network

Nearly 300,000 km of Roman roads mapped in new open digital atlas

Researchers behind the Itiner-e project have produced the most complete digital reconstruction of the Roman road system to date, charting 299,171 kilometres of routes across the Roman Empire at circa 150 AD. The dataset covers nearly 4 million km² across Europe, North Africa and the Middle East and compiles centuries of archaeological, epigraphic and historical evidence into a single open resource.

Scope, classification and key figures

The atlas comprises 14,769 road segments and distinguishes two hierarchical levels:

• Main roads: 103,477.9 km (34.58%) — routes documented by milestones or historical sources that structured imperial administration and military movement.
• Secondary roads: 195,693.3 km (65.42%) — local and regional connections that reveal everyday mobility.

Importantly, the project reports differing confidence levels for mapped routes: only 2.737% of segments have a certified spatial location, 89.818% are classed as conjectural and 7.445% as hypothetical. These proportions highlight the distinction between evidence that a road existed and precise knowledge of its exact course.

Methodology

The Itiner-e team combined three complementary steps to build the atlas:

1. Identification — compiling archaeological, historical and epigraphic sources: excavations, field surveys, milestones, ancient itineraries such as the Antonine Itinerary and the Tabula Peutingeriana.
2. Spatial localisation — cross-checking textual and archaeological evidence against modern and historical topographic maps, aerial photographs (including 1950s USAF imagery), satellite images and Corona programme photography (1967–1972). Corona images were particularly valuable for areas now submerged by reservoirs.
3. Manual digitisation — tracing each segment along the real terrain (mountain passes, valleys and corridors) at a spatial precision between 5 and 200 metres rather than drawing straight, simplified lines.

The project also used the LIRE (Latin Inscriptions of the Roman Empire) database to link epigraphic finds with mapped locations; the database includes 8,388 milestone inscriptions that helped anchor routes.

Uses, gaps and future work

Itiner-e includes confidence maps that visualise where documentation is weakest and where future fieldwork would most improve the atlas. The high spatial resolution enables new computational studies of connectivity, transport costs, administrative reach and the spread of goods, people, ideas — and even disease — across ancient networks.

"The extensive dataset produced by Itiner-e fundamentally changes how we can study the Roman road system’s role in moving people, goods, ideas and disease in antiquity," said project leaders Pau de Soto, Adam Pažout and Tom Brughmans.

Regions best documented include the Iberian Peninsula, Greece, North Africa, the Levant and Asia Minor, helped by earlier projects such as Mercator-e and Desert Networks. By contrast, the map highlights under-documented zones that are priorities for future research: northern England (including Cornwall), the middle and upper Danube, Tuscany, Corsica and central Anatolia. The North African deserts and some mountainous areas also present major documentation challenges.

As an open, interdisciplinary and collaborative platform, Itiner-e is intended as a living resource: researchers can contribute new data while retaining authorship and the public can access the atlas free of charge at https://itiner-e.org.

Why this matters

With nearly 300,000 km of documented routes — roughly twice the coverage of previous digital resources — Itiner-e transforms our ability to study the logistical and administrative infrastructure that underpinned Roman power for centuries. The atlas not only aggregates earlier knowledge but also pinpoints where evidence is thin, helping to focus archaeological fieldwork and future research.