A new data visualization reveals exactly how serpentine some cities’ road patterns can be. Stephen Von Worley–whose previous work includes visualizing McDonald’s locations across the states and how men and women talk about colors–took to his blog Data Pointed to map street layouts based on the cardinal orientation of each city’s grid pattern.
Von Worley took metro-area grids from OpenStreetMap and used an algorithm to color every public street according to a tweaked version of this circular rainbow color gradient. Neat, orderly grids oriented north-south and east-west are marked in red, while streets that bend and wind in other directions are rendered in different colors according to how their orientation on the compass corresponds to the color wheel–one 90-degree change in street direction corresponds to one revolution around the color wheel (back to red). Streets skewed at 30 degrees appear blueish, for instance, while streets skewed at 60 degrees appear greenish.
The maps reveal the major differences in how cities across the world are laid out. Old cities, like London and Paris, appear as rainbow mishmashes of winding roads and neighborhoods, while more modern metropolises, like Chicago, adhere so strictly to a well-planned grid system that they show up almost entirely in a monochromatic red. The coloring system reveals how geographic features, like the waterfront or a winding river, further influence how streets are oriented. (Chicago’s orderly grid is broken most often by the city’s meandering Lake Michigan shoreline.) In suburban Southern California, dead-end suburban residential streets curve and wind, becoming a rainbow, in bright contrast to the interconnected red grids of downtown L.A.