Digital mapping shows most of the Roman road network is unlocated
A large-scale digital reconstruction of the empire's road network reported that the precise course of only around 2.7% of Roman roads is known with certainty on the ground; the rest is inferred from itineraries, milestones, place-names and terrain modelling. An observation about the state of the evidence, not about Rome: the network everyone pictures is mostly a reconstruction.
Observed — measured or witnessed, with the observation cited.
Subjects
- The Roman Road Network · network · Mediterranean-wide, from Britain to Mesopotamia · not located
- Via Appia · route · Italy · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent. This is the standing of the weakest source, not an average.
Digital reconstruction of the Roman road network (DARMC and successor mapping projects)
Network models place total Roman road length between roughly 80,000 km (major viae only) and c. 192,861 km across c. 7,154 modelled segments at the empire's peak, depending on inclusion criteria. A 2025 mapping effort reported that the exact course of only about 2.7% of the network is known with certainty.
Digital Atlas of Roman and Medieval Civilizations, Harvard University; reported in la Brújula Verde · DARMC ongoing; mapping report November 2025 · Partly verified
Digital Atlas of Roman and Medieval Civilizations, Harvard University, https://darmc.harvard.edu/ ; 2025 mapping report at https://www.labrujulaverde.com/en/2025/11/the-most-detailed-map-of-the-roman-empires-road-network-reveals-that-we-know-with-certainty-the-location-of-only-27-of-its-roads/
Itinerarium Antonini Augusti (Antonine Itinerary)
A late-imperial register of routes listing over 2,000 places and on the order of 70,000 km of itineraries from Britain to the Levant, with stage distances. It is the single most important textual source for reconstructing the road network and shows that the state maintained systematic route knowledge as an administrative instrument.
Teubner (ed. O. Cuntz, Itineraria Romana I, 1929) · compiled late 3rd - early 4th century CE · Partly verified
Itinerarium Antonini Augusti, in O. Cuntz (ed.), Itineraria Romana vol. I, Leipzig: Teubner, 1929; overview at https://www.britannica.com/topic/Antonine-Itinerary
Recorded on The Roman Road Network
- Construction of the Via Appia begins
- The empire reaches its greatest territorial extent
- Digital mapping shows most of the Roman road network is unlocated
Related
Related because they share a subject in the Atlas — never because the text looks similar.