(MAPS) Painting By Number

Here's a little thing I discovered about Chicago: the higher a street's number, the further south it is from the city center.

You can see this very clearly on North America's Numbered Streets. This interactive map colors "all streets with a '#st', '#nd', '#rd', or '#th' in their name in North America, as drawn from OpenStreetMap." 

Zoom in on a city on North America's Numbered Streets and, if it uses a numerical street-naming convention, you'll probably notice that the smallest numbered streets are near the center of the city, while the largest numbers stretch out into the suburbs. In most cities, however, the numbers don't radiate outwards from the center. This is because streets are generally numbered in one cardinal direction. As a result, the redder (higher-numbered) streets will start appearing predominantly in one direction as you move away from the center.

For example, Denver is the numerical opposite of Chicago: while Chicago's streets become increasingly red as you travel south, Denver's streets become redder as you move north.

North America's Numbered Streets is a simple map, but it makes an otherwise mundane feature of the urban landscape surprisingly visible. Zooming around the continent reveals that the humble numbered street can tell you quite a lot about how a city is laid out.