Brave Mappers of Wherever You Are

Posted by mvexel on 23 April 2014 in English (English)

From time to time someone will ask me: 'How do I find out who my fellow local mappers are?'

That can be a surprisingly hard question to answer. You can go to your user page and see a few people who have indicated their 'home location' to be near yours. OSM user page map That does not work so well for a variety of reasons:

  1. Not all people set their home locations. My guess is most people don't.
  2. People don't update their home locations when they move.
  3. The home location is not necessarily where that person is mapping.

You can also have a look at Pascal Neis's wonderful 'Overview of OpenStreetMap Contributors aka Who's around me?' map, which gives you a visual impression of mappers in your area based on actual mapping activity. Pascal's page in action This is much better! But it still does not always give you the complete picture. For example, if I navigate to Salt Lake City, where I have lived and mapped for three years now, I can't find myself on that map. I guess I am mapping too much in other places for Pascal's algorithm to detect me as a local mapper.

Dennis Zielstra's engaging talk 'Where Are The US Mappers At' at State Of The Map US 2014 made me revisit this problem (and dig up some old code, more on that in a bit). He presented an in-depth analysis on user engagement and community activity for top US cities. Following that talk, I had a few interesting discussions focusing on questions like

What to do about those cities that do not have an active local community?

How can we make it easier for people to start organizing their community locally?

If we're going to address these questions, we need a better way to identify who active mappers in our area are, and contact them.

For contacting, we will need the groups functionality on that has been under development for a while. Being at SOTM US and catching up with lots of mappers from all over made me eager to get this project going again.

For identifying, I think I can contribute something. I wrote some code on top of osmjs a couple of years ago that I dusted off. It processes a full history planet file for an area and outputs stats for all users who have ever contributed in that area, things like:

  • First and last edit
  • Total number of edits
  • Number of edits still visible in today's data

I ran it on Los Angeles county and this is what came out. As a list, it is already pretty insightful, but you can roll nice visualizations with it as well. Enter the Brave Mappers Of Wherever You Are project that was sitting under the same layer of dust. I ran it on the LA county output with this result.

Brave Mappers of LA County

Brave Mappers shows a timeline of mappers for your area based on historical OSM data. A long bar is a mapper who has been active for a long time, like techlady here:


The users are sorted by how long they have been active in this area. Scrolling down, there are some interesting outliers to be seen. Here is DaveHansenTiger, the original TIGER import account:


As expected, active for a short time right at the beginning of the timeline. The green color of their bar means that they mostly created things (rather than modifying or deleting). The transparency indicates most of their work is no longer in the current data. In this case that is probably a good thing!

Finally, clicking on a user's bar gives some more details on their contributions:


If you want a Brave Mappers page (or just the spreadsheet) for your area, that can be arranged! If you feel up to it, you can clone the OSMQualityMetrics repo and run UserStats.js yourself on a full history planet for your area, then process it with the script in the bravemappers repo. Or you can send me an OSM POLY file and I will try and make some time to do it for you!

Comment from stragu on 25 April 2014 at 11:58

Great tool! It would be great to see that integrated in a website that would be accessible to every mapper. Extremely useful to organise a local event and find out who has been active in the last few months to contact them first.

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