To visualize the progress of OpenStreetMap as its contributors map their local communities and the world, I’ve been using Mark Newman’s cartogram tool to distort world maps, making the areas where OpenStreetMap has been edited the most appear the largest.
A cartogram from mid-2006 data highlights how focused the early OpenStreetMap project was on the United Kingdom, with most of the rest of the data in a few places in Europe. The map is comparatively tiny in North America, except for some areas of detail in Wisconsin and around the Chesapeake Bay. The relative prominence of Antarctica shows how little map data there was for most parts of the world.
With the United States map filled in, the bulk of mapping activity moved back to Europe, where by mid-2009, the work put into mapping Germany made it visually dominate the cartogram.
2010 and 2011 saw great increases in mapping in Canada, France, and Japan, as well as continued additions and corrections in large US cities.
The most recent available OpenStreetMap history file, from February, 2013, shows some recent map growth in New Zealand, and that the map has continued to improve in Canada and Russia. It also highlights, though, how disproportionately well mapped Europe and the United States continue to be compared to the rest of the world, in spite of some recent work in Africa and South America.