Roman communication costs in time and expense

The Stanford Geospatial Network Model of the Roman World

“For the first time, ORBIS allows us to express Roman communication costs in terms of both time and expense. By simulating movement along the principal routes of the Roman road network, the main navigable rivers, and hundreds of sea routes in the Mediterranean, Black Sea and coastal Atlantic, this interactive model reconstructs the duration and financial cost of travel in antiquity.”

For the pointer I thank Michael Gibson.


If you want a good reminder of how it's historically been much cheaper to ship stuff by water versus by land, take a look at the Roma-Tarraco route. Sending 1 kilogram of wheat by ship, selecting the "river"/"open sea"/"coastal sea" options, costs about 0.86 Denarii. But sending it over land by selecting only the "road" option costs 39.75 Denarii, nearly 46 times as expensive as sending it by water.

Shipping still is the cheapest way to send cargo, even in the age of railroad and reliable highways. That's why cargo ships keep on getting bigger.

Your mode of transport would almost certainly eat your wheat before it got that far by land.

Petroleum is routinely moved around nowadays by petroleum-fueled conveyances, you know. You just factor in the cost of consumed fuel into the price of getting the payload to its destination. Likewise with moving bushels of grain around on grain-fueled conveyances.

Petroleum-fueled conveyances are much more efficient than grain-fueled animal conveyances. If more than a bushel of a grain has to be consumed to transport a bushel, it's hard to charge enough to make it worthwhile.

Yes, and river transport was hugely more important in ancient and medieval times. Routes that today go by sea or land would go upriver, a short hop by land, and the rest by another river.

Somebody needs to tell Jeff Bezos he needs to start building canals and aqueducts.

In a way, that was Robert Fogel's controversial argument: railroads were not a critical part of the Industrial Revolution he suggested, because canals could have accomplished much the same growth of transportation infrastructure. That led to a storm of commentary (one article was subtitled "Professor Fogel On and Off the Rails") and AFAIK it's still not a settled issue. But the more that I learn about how shipping via boat has been providing low cost transportation for millenia, the more that I think Fogel may've been right.

Railroads beat boats for most energy efficient way to transport things, for fossil fuels. Sailboats and Erie Canal do not count.

The Stanford website was designed poorly; using a Firefox browser made my computer hang, I had to reboot. They warn to use only Chrome or Safari, but this is poor design, akin to the US Obamacare websites. Better to have used Silverlight and made users install a plug-in. I still don't know why the anti-Microsoft crowd hijacked public opinion and killed Silverlight.

Ray, Australian rail and domestic ship transport are fairly close in energy use as measured in tonne-kilometers. However, between some cities rail freight will cover a shorter distance. Note this is for oceanic cargo transport. We have these water filled cracks in the ground called rivers, but not the sort of things one can reliably float a boat in.

If one bad website forces you to reboot your computer, you should rather be examining your OS choice.

There's a good reason the anti-Microsoft crowd exists & their crappy internet browser may not be the key reason.

When you say railroads beat boats is that before or after accounting the energy that'd go into building the infrastructure?

@Rahul, obviously both before and after. The sunk costs of infrastructure will only delay when energy by rail beats water by a few years (or decades at most).

How exactly does one "hijack" public opinion? By forcing people to agree with one's position at gunpoint?

"Duration" depends on the winds. Variable blighters, winds.

Pax Romana!


It should be noted that the cost estimates only apply to cargo. They are not very useful for passenger costs or rates, which were much higher.

Demonstrates why large nation-states were more vulnerable and had to rely on commanders and governors in the field to make decisions supporting the central authority. It's also a reason why modern communications makes central authority more dangerous.


I'm sympathetic to arguments that evil of the likes of Hitler & Stalin succeeded in the 20th century to a large part because of how efficiently central orders could be transmitted & executed. If regional commanders were forced to take more initiative & independent decisions this would be harder.

Evil has always existed but getting evil to scale was the novel accomplishment.

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