The Roman Road Network

By 117 CE the empire ran on roughly 80,000 miles of built road, engineered to a standard that let a courier cover 50 Roman miles in a day and a laden ox-cart move without breaking an axle. Distances were measured in Roman miles (mille passus, "a thousand paces," about 1,480 modern meters) and marked by milestones (miliaria) that gave the distance to the nearest city and, often, which emperor had paid for the surface.

The roads were built for the army first and everyone else second. A legion on the march needed a graded, drained surface it could keep moving on in any weather, and the empire's core network — the Via Appia south from Rome, the Via Egnatia across the Balkans to the Bosphorus, the Via Domitia through southern Gaul to Spain — began as conquest roads before they became trade and travel corridors.

Every 12 to 18 Roman miles or so, the road met a mansio — a staging post with stabling, a change of horses for the state courier system (the cursus publicus), and rooms for travelers with the right permit (a diploma, issued by the provincial governor's office). Smaller mutationes in between offered only a horse change, no beds. A private traveler without a diploma paid for the same amenities at a roadside inn (caupona) instead.

Below, every road station on the map with a name and a source is grouped by road. Most come from the Antonine Itinerary (Itinerarium Antonini), a Roman-era route gazetteer compiled around 300 CE from older imperial records — it lists each stage of a journey with the distance to the next stop, exactly the way a modern driving-directions app would, just for a road network that was already centuries old by the time it was written down.

Sources

• Itinerarium Antonini (Antonine Itinerary)
• Raymond Chevallier, Roman Roads
• Ray Laurence, The Roads of Roman Italy
• CAH XI, The High Empire, 70–192 CE (Cambridge Ancient History, 2nd ed.)
• Fergus Millar, The Roman Near East, 31 BC–AD 337
• Barrington Atlas of the Greek and Roman World

More to read

• The Roman Army in 117 CE →
• 11 August 117: The Day the Empire Peaked →
• Trade, Coinage & the Roman Economy →
• Religion & the Sacred Landscape →