Sunday, June 29, 2014

OpenStreetMap Worldwide Coverage

Martin Raifer has released a beautiful map of OpenStreetMap Node Density. The map provides a general overview of OpenStreetMap's global coverage.

Each pixel on the map shows the number of nodes at that location. When comparing areas on the map you need to carry out a sort of population normalization calculation in your head. For example central Australia appears darker on the map than some of the Australian coastline. This is more than likely due to the fact that urban conurbations are mainly on the coast and therefore there will be more map features than in the less densely populated areas in the middle of Australia. You also need to remember that the map uses a Web Mercator projection and therefore this makes it more difficult to compare locations at different latitudes.

In Europe the Netherlands seems to have the highest node density. Is this because the Netherlands has a huge number of OpenStreetMap contributors or just a reflection of the relative urban density of the country? In the USA California shines out, particularly central San Francisco and Bakersfield. My guess is that Bakersfield in particular must have a pretty dedicated team of OpenStreetMap contributors.

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