ORBIS   The Stanford Geospatial Network Model of the Roman World
Walter Scheidel
Elijah Meeks

Spanning one-ninth of the earth's circumference across three continents, the Roman Empire ruled a quarter of humanity through complex networks of political power, military domination and economic exchange. These extensive connections were sustained by premodern transportation and communication technologies that relied on energy generated by human and animal bodies, winds, and currents.

Conventional maps that represent this world as it appears from space signally fail to capture the severe environmental constraints that governed the flows of people, goods and information. Cost, rather than distance, is the principal determinant of connectivity.

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.

Taking account of seasonal variation and accommodating a wide range of modes and means of transport, ORBIS reveals the true shape of the Roman world and provides a unique resource for our understanding of premodern history.

mediterranean routes

In the aggregate, our model simulations make it possible to reconfigure conventional maps of the Roman Empire to express the relative cost of transfers from or to a central point as distance. This perspective captures the structural properties of the imperial system as a whole by identifying the relative position of particular elements of the network and illustrating the impact of travel speed and especially transport prices on overall connectivity. Distance cartograms show that due to massive cost differences between aquatic and terrestrial modes of transport, peripheries were far more remote from the center in terms of price than in terms of time.

Due to an unexpectedly high volume of traffic to the site, performance of the routing map and interactive cartogram are not what they should be. If you experience delays performing route calculations or rendering the map, you can try refreshing the map by zooming in or out. Please do return next week -- these issues should be entirely solved by then. We are very sorry for any inconvenience!
Calculated route
A KML-formatted file can be loaded in Google Earth, and some other mapping applications. Save the file with an extension of '.kml' -- for example, routes01.kml.

A comma-separated date file. You can:

'Open with...' a spreadsheet program or text editor, or
Choose 'Save as...' and rename with and extention of '.csv' -- for example, routes01.csv

An explanation of the abbreviated terms, e.g. 'slowover'
geographic map distance cartogram