A subway diagram works by throwing away geography. It keeps which line connects to which, and discards distance, direction and everything else. Alexandr Trubetskoy applied that logic to the major Roman roads of the empire around one hundred and twenty-five, pulling on Stanford’s model, the Pelagios Project and the . What does the form cost?
Names, mostly, and the shape of a journey. Some lines are genuine named roads, the and the Via Militaris among them, while others had no known historic name, so he invented plausible ones. The map also implies you would travel Petra to Gaza by way of Damascus and change onto the , which no traveler would. Roads are not rails.
A subway diagram is a deliberate distortion. It preserves the order of stops and the places lines meet, and throws away distance, direction and scale, because a passenger needs to know where to change and not how far anything is. Applied to the Roman road network of about one hundred and twenty-five, it yields a striking picture and a philosophical problem at once.
The research took more than expected, because no single consistent source covers it well. Trubetskoy worked from Stanford’s ORBIS model, the Pelagios Project and the Antonine Itinerary. The lines mix genuine named roads with roads that have no known historic name, for which he invented some, and his notes separate the two lists carefully.
Several names are real but stretched. The Via Latina he merged with the Via Popilia, though in reality the Popilia ended at Capua and the Latina ran on to Rome. Via Aquitania properly described only the stretch from Bordeaux to Narbonne. Via Claudia is not a real name at all, though it marks a real continuous road built by Claudius. Via Sucinaria is the Latin for the Amber Road, a trade route rather than a single paved thing.
The deeper flaw he names himself: roads are not rails. Nobody traveling from Petra to Gaza would detour through Damascus to change onto another line. The travel figures he gives make the same point about what the diagram cannot show. Walking Rome to Byzantium in summer took about two months, and a month on a horse. By horse and sailboat together it took about twenty-five days, since no sane Roman used only roads where sea travel was available.
wat. He drew the roads as a subway, then published a list of every place the metaphor lies.
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The notes are the valuable part. A popular diagram that lists its own fictions, line by line, is rarer than a diagram that gets everything right.
How do we know?
Trubetskoy published the map with notes setting out his sources, the roads whose names and paths are authentic, the ones modified, the ones invented, and the travel times behind them.
What is still unknown
He says plainly that no single consistent source is particularly good for this, and that choosing which roads and cities to include was the biggest creative element. He also admits to never having formally studied Latin.
Learn something?