Take 60,000 random points inside a country. Route each one to the capital along real roads. Plot every trajectory. What appears is a glowing dendrite: the same topology as blood vessels, river deltas, and lightning.
Over the course of billions of years of selection and fine tuning, biological systems have developed networks adapted to a diverse range of conditions. Blood and nerves. Plant veins and roots. Rivers and lightning, finding their route through the medium.
Since cities exist we have run the same course, for the same reason: keeping the body connected. Our roads grew following the same patterns, because they are the same kind of object. A circulatory system, drawn at planetary scale by every commuter, every cart, every wheel that ever rolled.
The image is not a metaphor. It is a measurement. Tens of thousands of real routes through real roads, drawn at once, become the shape humanity has actually made.
Madrid sits dead-centre of the radial road star Spain has built since Roman times. The N-1 to Irun, N-2 to Barcelona, N-3 to Valencia, N-4 to Cádiz, N-5 to Lisbon, N-6 to A Coruña: six trunk lines pulsing out from the capital, then branching into capillaries that cover the entire peninsula. Mallorca shows as a smaller pattern off the east coast.
Stockholm sits on the south-east coast, so Sweden’s network reads as a long spine reaching north along the E4 and the Bothnian coast, with a dense web in the south through Göteborg and Malmö. Above the Arctic Circle the dendrite thins to single branches threading between lakes and forest.
It is not a stylised effect. The brightness is just overlapping routes.
This recreates the 2017 Road Trees series by SThAR, an EPFL spin-off led by Alberto Hernando. The original gallery has been offline since around 2018; what you see here is built from the same recipe, rerun on a current OSM extract.
Credit. Idea, recipe, and original 2016 to 2017 visualisations: SThAR (Switzerland), Alberto Hernando de Castro, et al., archived at web.archive.org/web/2017/http://roadtrees.com/. Tooling: OpenStreetMap (data), Project OSRM (routing engine), GADM (boundaries), datashader (rendering), Python.
This page is part of IamI.Earth’s ongoing demonstration that planetary intelligence is not a metaphor; it is something a species literally builds, and the shapes it leaves are measurable.