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MapRoulette
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Creating a Challenge

Creating a challenge starts with a good challenge idea. Good challenges have tasks that:

Here’s an example challenge that meets that criteria. We will ask mappers to review motorway_junction nodes in the United States that have name tags. This is uncommon in the U.S. Often mappers will add a name tag that has the destination information on it, so the information renders on the map:

This Overpass query selects all these nodes.

area[name="United States of America"]->.a; node["highway"="motorway_junction"]["name"](area.a); out meta;

With that query in hand, I can go to MapRoulette and click ‘Create’ at the top. This takes you to your MapRoulette Projects page. By default you will only have one Project. Click on its name to select it as the home for your new Challenge. At the top of the Project page, you will find the ‘Add Challenge’ link, click that to start the wizard to add a new Challenge.

The Wizard has 4 pages, but only the first two require your full attention

On the first page you enter the title, description and instruction for your challenge, as well as some metadata that will be used to help others find it and identify edits made by mappers using the Challenge:

I used Motorway junction nodes are not commonly tagged with name. This challenge asks mappers to review those nodes, removing the name where it’s not applicable.

When all this is filled out, you can proceed to screen 2, where you supply the source data for the tasks. This can be a GeoJSON file or URL, or an Overpass query. If you use an Overpass query, make sure you don’t use any Overpass Turbo specific language such as geocodeArea:.... Test your query in Overpass Turbo first.

The final two screens let you add rules to prioritize certain tasks over others based on OSM tags, and let you define some view related settings for your challenge. The defaults are sensible but please do review them and tweak as needed. Make sure that the query only returns the nodes or ways that you want mappers to review, and ideally the number of objects returned should be no more than a couple thousand.

When you click ‘Finish’, MapRoulette will query Overpass in the background and populate your challenge. Depending on how heavy the Overpass query is, this can take a few seconds to a couple of minutes. When it finishes, you will see a map with your tasks, a complete list of tasks and some more challenge information.

You can now click Start on the top to go directly to your challenge and try it out!