Find your MapRoulette Challenge

MapRoulette is a fun way to spend a few minutes (or hours…) improving OpenStreetMap. MapRoulette will present you with a random, easy to solve issue in OSM. MapRoulette is organized in ‘Challenges’, groups of tasks that are of the same nature. For example, there is a challenge to add missing crosswalks in various areas in Switzerland, based on analysis of aerial images.

How do you find a challenge you would like to work on? The MapRoulette home page provides a map of all the challenges, but this has some shortcomings. The challenge ‘centers’ are no

t always representative of where the tasks actually are located. It is also hard to search by topic. MapRoulette also has a search bar that you can use to find a challenge by keyword.

I want to work on making it much easier to find

 interesting MapRoulette challenges, and I would like to hear from you how you think that should work. Please add a comment below with your ideas!

In the mean time, I made a page that lists the most popular and newest challenges. It is a bit of a hack so let me know if it stops working 😉

Happy Mapping!


Help fix up TIGER v1 ways

Old, untouched TIGER ways are still abundant in OSM 🙁 and fixing them up seems to be an endless task.


I don’t know why I didn’t do this before, but I finally got around to making a MapRoulette challenge so we can fix them together:

>> Go to the challenge <<

Because the number of old TIGER ways is huge, this challenge covers only a tiny part of the U.S. as you can see here:

Once this part is done, we can reload the challenge with more old TIGER ways.

If you look at the screenshot above, you can also see what the query is that goes into Overpass to create the challenge in the first place. You can easily adapt it to make your own local challenge if you want to start fixing up old TIGER ways with your local mapping friends! (Why not organize a TIGER fixing party? OSM US will pay for pizza!)

If you’re interested in the Overpass details and some ideas for improving it, keep reading. Otherwise, just start fixing! 

Query Overpass for old TIGER

Here is my extremely simplified way to query Overpass for old TIGER ways:

way[highway]["tiger:tlid"](40, -113, 41, -111);
out body geom qt;

It takes the bounding box (40, -113, 41, -111) and searches for ways that have the highway tag as well as the tiger:tlid tag. This query should be a pretty good approximation of a real old TIGER way query, because the tiger:tlid tag is removed automatically when you edit such a way in iD or JOSM. So any way that still has this tag must not have been edited since the import.

This query falls short of a real old TIGER ways query, because the nodes that make up the way may very well have been edited. I am also not 100% sure under which circumstances the editors remove the tiger:tlid and other unnecessary TIGER import tags. It may be safer to look for last edited date or version number. If you have suggestions for improvement, please let me know in the comments.

Happy mapping!


Mapping traffic signals and stop signs using MapRoulette

In our journey of improving  the OpenStreetMap we are constantly searching for  open source data. This search is very important and is done before we start improving the map in a new area.

Currently, part of our team is focused on improving the Detroit area. So, before we started mapping we searched for useful geospatial data and we came across open data about traffic signals and stop signs for Wayne County, Detroit. The data can be found here and here.

Traffic signals mapped in OSM
Stop signs mapped in OSM

We filtered out the traffic signals and stop signs that were already in OSM but there is still a significant amount of data that can be added in OSM. (912 – traffic signals and 8755 – stop signs). Due to this, we thought about creating a MapRoulette challenge.

About MapRoulette

MapRoulette is a micro-tasking tool used to fix bugs in OpenStreetMap and to improve it. A user can create tasks by uploading files which contain the location, ways, points with the error that has to be fixed or files with features that are missing from the map and can be added by other users.

When creating a new task, the user gives specific instructions on what steps have to be followed to edit through this tool. Once a user has logged in, he can see on the map the created challenge and the pins which consists of tasks he can solve.

So, given the available data that we found, we created two challenges – one for traffic signals and the other for stop signs. Some general rules for mapping traffic signals and stop signs can be found on the OSM wiki – here and here.

Tags that we use for mapping
  • Stop signs – highway=stop
  • Traffic signals – highway=traffic_signal
  • If the traffic signal/stop sign is referring to all the highways entering the intersection, we add the traffic signal/stop sign in the intersection point.

  • If the traffic signal/stop sign is not referring to all the highways entering the intersection we add the traffic signal/stop sign before the intersection, where the sign/signal is positioned.
  • We need to add an additional tag if the road is bidirectional:
    • for traffic signals we use the traffic_signals:direction key with the forward or backward values to indicate the affected direction.

    • for stop signs add direction=forward or direction=backward to indicate the affected direction.

The data has been published under Public Domain license.

Everyone who is keen on mapping is welcomed to help us.

Let’s improve OSM together!


Help map some sidewalks for cities in the U.S.

United States cities are built for cars, with very few exceptions. From where I am sitting right now, I see this:


Cars zooming by incessantly at 70kph.

Finding your way in an urban space that is designed this way is tricky – and often dangerous – if you are walking or bicycling. Sidewalks are often not present, crossing streets can be very dangerous or even impossible. OSM has great tagging for bike lanes and sidewalks, but I find that these crucial tags are often missing on ways that need them most: the four or six lane urban arterials that you see in the picture above.

As I was sitting here asking myself how on earth I would get back to my hotel (which is 10 minutes away) safely, I thought to myself: ‘we can fix this problem and make the world a bit safer for those who can’t or won’t drive.’

MapRoulette to the rescue!

I created this challenge highlighting all primary and secondary ways that have nosidewalk tag in Tampa, Florida. (I am actually in Sarasota now, south of Tampa, but I already fixed all the ways there so that would be a boring challenge.) The idea is to look at the aerial image in JOSM or iD, see if there is a sidewalk, and add the appropriate tag. Adding sidewalk=no is actually just as important as adding both, right or left. Here is an example way from this challenge:


Even zooming further in there is no sight of a sidewalk:


So let’s add that information:


And upload!

Create a Challenge for your city

The fun part is that you can easily replicate this challenge for your own city. Here’s what to do.

Overpass Turbo

First you head over to Overpass Turbo and run the query that highlights all highway=primary and highway=secondary that have no sidewalk tag:


You can use my query as a template, replacing the GeocodeArea with the name of your city.

Once you have the results, export them to GeoJSON. Let’s use a gist:



You can now click on the gist link and see the result on GitHub as well:


We will need the ‘raw’ GeoJSON content, so click on the ‘Raw’ button and copy the link it leads you to.


Next we’ll use a little tool I created to easily turn the contents of a GeoJSON file into a MapRoulette challenge. To get it, head over to the Github repository and follow the instructions to install the tool.

The tool takes its configuration from a YAML file. The samples directory contains an example for this sidewalks challenge you can use as a template:

# the base URL for the MapRoulette server API to call
#server: "http://localhost:5000/api"

# server API admin credentials
user: devuser
password: mylittlesony

# source file or URL. You can give a list of URLs too, all data will be gathered and added to the same challenge.
# source_file: ....

# source geojson property key to use as your task identifier (optional, will use random UUID if not given)
# identifier_property = ...

# Challenge metadata, see for background
slug: sidewalks-sarasota
title: Add sidewalks to major roads in Sarasota
instruction: This way has no `sidewalk` tag. Usually you can see from the aerial imagery if there is a sidewalk or not. Please add the appropriate `sidewalk` tagging.
help: "Help make OSM be a better resource for safe, walkable streets! Many primary and secondary roads in the US are not safe for pedestrians if there is no sidewalk. This challenge highlights all `primary` and `secondary` ways that have no [`sidewalk`]( tagging whatsoever. You can help by looking at aerial imagery and adding the appropriate `sidewalk` tagging. `sidewalk=no` is just as important to have as the 'positive' values. Thanks for helping make OSM better!"

The only items you would need to change are the source_url (use the raw GeoJSON github link you just copied), the slug (use sidewalks-YOURSTATE-YOURCITY or something similar – this will be the challenge URL component in MapRoulette) and the title (change the city name).

By default this configuration will post to If you want to post you would need to get in touch with me to get the credentials.

Once you have the YAML config file in order posting to MapRoulette is as simple as:

$ ./ samples/sidewalks-sarasota.yaml --post --activate
Posting 364 tasks...
server alive: True
Updating challenge...
Reconciling tasks...

Let me know if you need any help with this or if you want me to create a challenge for you!