From OpenStreetMap Wiki
Jump to: navigation, search
Available languages — MapRoulette
čeština Deutsch English français
Screenshot of MapRoulette
Author: Martijn van Exel, Serge Wroclawski
Version: 20140729 (2014-07-29)
License: Apache (none)
Platform: web

Towards a better map, one bug at a time.

MapRoulette ( is a gamified approach to fixing OSM bugs that breaks common OpenStreetMap data problems into micro tasks. Grab yourself a small task and start improving OpenStreetMap!


The tasks that need fixing are set into challenges, and a tutorial is created for the current challenge, to aid users into how to best fix the issue. Only one challenge is active on MapRoulette at one given time. Once all the issues have been fixed, a new challenge is activated.

Challenges: examples

Name Definition How to solve
Bad Ramp Angles All the ramp edges where there are either sharp angle turns to or from the edge. Two way ramps are also considered to be part of this challenge.
BadRamp Angles.png
You need to correct the ramp angle or possibly mark the ramp as one-way.
Connectivity Error Ways that are almost connected and probably should be.
Connectivity error.png
Check if the ways should be connected in the real world. For this you could use Imagery layers or Mapillary images.
Equivalent Ways Edges that connect the same nodes and have the same shape:
Equivalent ways.png
Determine if two or more ways connect the same nodes with the same shape and correct it.
Miscategorized Links Signals ways that have been mislabeled. The way might be a link (ramp or connector). Check the way tags and if it is mislabeled add the correct tags.
Misnamed Double Digitized Ways Signals double digitizes roads where one side of the road has different characteristics than the other side. For example, names may mismatch ("Las Vegas Boulevard" vs "South Las Vegas Boulevard"), or road classification may mismatch (Secondary vs Primary). Check the road tags and fix the inconsistent naming.
More Overlapping Ways Segments that are included in multiple edges.
MoreOverlapping Ways.png
Find the overlapping part and remove it, preserving the course of the way and its connections.
One Way Loops Locations where a user can enter a loop, but there is no exit. There are two types of problems:
1) There is an exit to the loop in the underlying data, but it is of a road type that is not supported (driveway for example).
2) There is no exit from the loop.

OneWay Loops.png

Correct the road direction problem that created a one-way loop.
Overlapping Ways Ways that have duplicate segments within a single edge.
MoreOverlapping Ways.png
Find the overlapping part and remove it, preserving the course of the way and its connections.
Sign Post Places where there is neither an old (exit-to) tagging at motorway ramp bifurcations, or a new (destination) tagging at such bifurcations. Determine if there’s a missing sign-post and correct it. You can use as reference imagery layers, Mapillary images or the ScoutSigns plugin.
Typos Signals slight differences between neighboring edges. Determine if there’s a typographic error and correct it.
Unexpected Dead Ends Signals dead ends in higher class roads. Check if there should be or not a dead end in real life.
Ways Needing Smoothing Ways that need smoothing and/or realignment. See this diary entry for more information about this challenge.
Smoothing way.png
The way has one or more unusually sharp angles. It can probably benefit from some smoothing and aligning with Bing imagery.
Zorro Ways Ways that have a Zorro appearance: two consecutive very sharp angles.
Zorro ways.png
Check and straighten out the Zorro shaped ways.

Ideas for new challenges

Share your ideas for future challenge ideas here.


Past MapRoulette incarnations have addressed redaction bot cleanup, folded ways in TIGER data and fixing connectivity bugs.


As a result of the License Change, a lot of OSM data was deleted or reverted back to a previous version. The first version of MapRoulette was geared towards repairing this damage by identifying all the ways that were gone and inviting users to re-add the removed ways using the standard OSM editing tools.


The remap-a-tron proved to be a very successful tool. Perhaps it could be repurposed to help get other types of map bugs fixed? At State of the Map US 2012 in Portland, the next iteration of what would become MapRoulette was announced: the Un-Zorro-Tron, to help fix Zorro Ways in the United States OSM data.


The domain was registered on October 13, 2012, as is considered as the founding date for the project.

See also



The code, issues, and documentation are available on GitHub.