The wait is over! As I mentioned in December, I have been working on an interactive online map, which shows you all volunteers of the OpenStreetMap world on a map. The first three layers contain the activity center of a contributor, her or his first created and latest modified node. The algorithm to determine the activity area of an OSM volunteer has been described in my publication here. I should mention that I used all changeset centers instead of all created nodes of a contributor. This way the computations don’t take as long and the process can be repeated every week based on the weekly OSM changeset dump.

The above image shows the created map for the center of London. As you can see, there are several Mapper-Types to choose from on the left side. Each mapper type is distinguished by the number of changesets that were created (shown in parentheses). However, most of the time you will see many orange or red figures on the map , which means that the OSM project has a lot of members who only made a few changes. This “issue” or “phenomenon” has also been mentioned in the publication.

Below the map you can find additional information which shows the current number of mappers in your map’s bbox. Sometimes the number is a little bit larger than the real number of contributors in your area. This depends on the method that Openlayers uses to load the mappers from my server onto the map. For the next update, I maybe plan to add the dates of the latest contribution of a member. This way you can get current information about the number of (active) contributors for your area.

The data will be updated on a daily and weekly base. It is also important to mention that each layer has a limit of 1.000 contributors to show on the map. Thus, if you zoom out, you will always see contributors, but sometimes the real number is much higher than the number of mapper icons you see on the map.

Last but not least some stats: Today (Jan 6th, 2012) the OpenStreetMap project has reached 1 000 000 registered members. Around 300 000 (30%) of all contributors created at least one changeset and about 200 000 (20%) volunteers created at least one Node. Of the 300 000 contributors who created at least one changeset, around 240 000 created less than 10 changesets, 45 000 (4.5%) between 10 and 100 changesets and 17 000 more than 100 changesets. I think this amount of 17 000 mappers or 1.7% of all registered members is obviously the amount of active OSM members. This is also comparable with the official OSM “highly active users” stats from here.

The map is online here:

Overview of OpenStreetMap Contributors aka Who’s around me?

¡Muchas gracias maɪˈæmɪ Dennis!