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MapRoulette 3.1.1 Release Notes

Posted by mvexel on 19 November 2018 in English (English)

MapRoulette 3.1.1 is now available on Here's what's new!

Mapillary layer

Mapillary images are now available as an overlay on the map. If you're zoomed in far enough you can select the Mapillary overlay from the Layer dialog.

This is a work in progress. Let us know if you have any suggestions to make it better! And yes, we plan to support OpenStreetCam images soon as well.

Rebuilding Tasks

MapRoulette now supports rebuilding tasks from Overpass based challenges as well as local and remote GeoJSON challenges. You can use the 'Rebuild' link at the top of you Challenge maintenance screen to start the process. For Overpass based Challenges, it will simply re-run the Overpass query. For remote GeoJSON files hosted someplace else, it will reload the GeoJSON from there. For local GeoJSON challenges, you will be prompted to select a new GeoJSON file to upload from your computer.

For a rebuild to work, you need to have assigned unique identifiers to Tasks in your Challenge. MapRoulette uses these identifiers to match the new Tasks with existing ones. We created a wiki page to explain this in more detail.

Public Leaderboards

Each Challenge now has a public Leaderboard page! You can access it on the Challenge Browse page.

The Challenge leaderboards work the same as the overall Leaderboard. You can select one month, three months, six months or a year for the period. You get 5 points for fixing a Task, 3 for marking it as Not an Issue or Already Fixed, and 1 point for marking a Task as Too Hard.

See also the Release Notes on Github for a complete summary with links to the relevant tickets.

MapRoulette 3.10 Release Notes

Posted by mvexel on 12 November 2018 in English (English)

MapRoulette 3.10 is now available on Here's what's new!

For Mappers

We made changes to the map layer selection. You can select more and more relevant background map layers in MapRoulette. The available layers are retrieved from the OSM Editor Layer Index. For aerial imagery layers, you can also select the Mapbox road overlay.

When browsing for Challenges, you can now sort the results different ways: by age, by popularity and 'smart' which also takes into account Featured Challenges and Challenges you saved. The old sorting by name is also still available.

Smaller improvements include support for Level0 as a preferred editor, more keyboard shortcuts and seeing the age of tasks when browsing Challenges.

For Challenge Owners

You can now use mustache tags in your Challenge description. These are placeholders for values that are unique for each task. For example, if you have a value lanes in your source task GeoJSON, you can add something like "We think this road has {{lanes}} lanes. Can you verify this using imagery and update OSM as needed?". When a task is shown to the mapper, the tag will be replaced with the appropriate value.

You can now organize the Challenge and Project administration screens the way you like them. All components are widgets you can drag, remove, and add. You can even create different views to see different sets of information at a glance.

We also support a new streamable GeoJSON format and give the option to ignore GeoJSON errors.

For the full list of features, bug fixes and changes see the release notes on Github.

Happy mapping!

Adding road names from TIGER using MapRoulette

Posted by mvexel on 9 November 2018 in English (English)

TIGER is the street database from the U.S. Census. An old version of TIGER was used to bootstrap OSM in the U.S. back in 2008. We have come a long way since then (see image below) and OSM is now much better than TIGER in most places.

Image from

New versions of TIGER are released every year and they are still useful. Local governments update it with new roads and street names. If you compare new TIGER data with what's in OSM, you get useful information about where OSM may need improving. If you edit in iD, you get visual cues when roads are missing:

You have to stumble upon them, though. And you only see new roads, not if a street that didn't have a name now has one.

My colleagues in the Telenav map team have run OSM and TIGER 2017 through our Cygnus conflation engine to find those streets in OSM that don't have names yet, but TIGER does have a name. We put them in MapRoulette for a few select areas.

MapRoulette is a micro-task tool that I built originally to clean up the redaction mess after the license change. These days, it is available to anyone who wants help to fix all kinds of small problems in OSM. Scroll through my recent diary entries and you will find blog posts about MapRoulette. Right now I just wanted to walk you through solving these TIGER based name adding challenges.

First I select one of the TIGER Challenges in MapRoulette, for example this one for New Orleans.

The first task I get is this one here:

I have three options on the left, Edit (which takes me to my preferred editor, you can set this in your MapRoulette user profile), Not an Issue for if you can already see on the map that there is no issue, or Skip if for whatever reason you'd rather leave this task to somebody else.

Clicking Edit takes me to my preferred editor, JOSM.

And in fact this street segment has no name. The TIGER roads overlay tells me that this is just a part of Lake Trail Drive. I fix the error and upload.

MapRoulette has already taken care of pre-filling a changeset comment and source, but you're of course welcome to tweak these to your liking.

After the upload completes I am ready to switch to MapRoulette in my browser, click I fixed it and go on to the next task.

Finally, here's a list of all TIGER name challenge we have currently. If you want your city or area included, let me know!

Happy Mapping!

MapRoulette Insider - Creating a Challenge

Posted by mvexel on 6 November 2018 in English (English)

In this post, part of the MapRoulette Insider series, I will show you how to create a MapRoulette Challenge yourself.

The first thing you need is a Challenge idea. Good challenges have tasks that:

  • Are easy to solve (typically less than one minute)
  • Do not require local knowledge
  • Involve only one or two OSM objects

My example challenge meets those criteria. I 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:

  • Visible Whether the Challenge will be listed. If no, you can still share the Challenge URL and it will work.
  • Name A descriptive name for the challenge. I used Review named motorway junctions in USA. A good title describes what the challenge is about is a few words.
  • Description Some text to describe in more words what the challenge is about. This field supports markdown and appears in the expanded challenge information when mappers browse for interesting challenges:

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.

  • Blurb Feel free to skip this. An even shorter description of what the challenge is about. I used Review named motorway junction nodes
  • Instruction This is perhaps the most important text. Here you tell mappers exactly what the task is you want them to perform. Be specific and use links (this field supports markdown as well) to the OSM wiki or other external sources where needed. This text is shown next to the map of the task location. I used This motorway_junction node has a name tag. This is uncommon, see the OSM wiki for details. If this name tag does not represent a 'name of the junction or interchange', the name tag should be removed. If you're not sure, you can skip the task.. Note how I use markdown features to make the instructions easy to read and comprehensive.
  • Changeset Description This field will be used to pre-fill the changeset description in the editor. I used reviewing named motorway junctions. A #maproulette hashtag will be added unless you change that default setting below.
  • Changeset Source This field will be used to pre-fill the changeset source field in the editor. If your task involves using any external data, you should list it here. I used maproulette;overpass.
  • Difficulty You can leave this at 'Normal' unless your tasks are particularly easy or hard. We may change this system in the near future..
  • Category This helps the user find challenges they are interested in. There is a dropdown menu on the main Challenge list that lets users narrow down the list by category. For this challenge I used Roads / Pedestrian / Cycleways.
  • Keywords These also help users find interesting challenges. They are used in the free text search field. I used junction, name, motorway and exit.

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!

Updates to Meet Your Mappers

Posted by mvexel on 27 August 2018 in English (English)

This post first appeared on my blog.

A few weeks ago, I built and released Meet Your Mappers, a web tool that lets you identify OpenStreetMap mappers in an ares of your interest. I received a lot of great feedback and encouragement and have addressed some of the main concerns people raised. Here’s an overview of the updates.

Box shaped areas of interest

The single most important piece of feedback I got is that the tool is too hard to use because of the need to identify the area of interest by looking up an OSM relation ID. This is error prone and unfriendly to those not too well acquainted with how administrative areas are mapped in OSM.

This was partly done by design (I didn’t want to make it too easy to use, because of the demands on my bandwidth and the Overpass API) and partly because I was lazy (I didn’t have to build a map widget).

But folks kept asking for it so I added a map widget so you can draw a bounding box to indicate your area of interest. The relation ID option is still there as well.

Alternate server

Apparently, the main Overpass server is not accessible for some people due to internet access restrictions, so I added the option to call an alternate server at

Mapper identification

MYM groups mappers into mapper types. If you mapped a lot in the area, MYM labels you a ‘Power Mapper’, for example. The applies only to the area of interest, because MYM cannot see what you may have mapped outside of the area it analyzed. I added some wording to make it more explicit that the Mapper Type is a local designation.

I also added an link to the ‘How Did You Contribute’ tool for each mapper. HDYC analyzes a mapper’s entire history for a more complete picture of how much and where they mapped.

Let me know what you think of these improvements, that are now live at

MapRoulette 3 Insider - Virtual Challenges

Posted by mvexel on 6 August 2018 in English (English)

This and future diary posts also appear on my blog.

After introducing MapRoulette 3, the micro-tasking tool for OpenStreetMap, I would like to follow up with a series of 'Insider' posts. Each of them will highlight an interesting feature or function of MapRoulette.

This week, we will look at Virtual Challenges.

Challenges in MapRoulette

MapRoulette consists of Challenges, which are groups of similar Tasks. An example is the Embassies missing representing countries Challenge by user johanemilsson. It asks you to add missing country=* tagging to specify which country the embassy, consulate or mission represents.

You can start working on this Challenge right away by clicking Start. That will take you to a random Task. Because this Challenge has Tasks all over the world, you could land anywhere. This is why it is called MapRoulette -- the 'Roulette' wheel spins and you get a random task! What is nice about this is that you get to improve the map all over the world, and see what the map looks like in faraway places.

But what if you want to focus on improving one specific area? MapRoulette makes this possible too, with Virtual Challenges. Let's talk about how to use those!

Creating and Using Virtual Challenges

A Virtual Challenge is a Challenge that consists of a custom group of Tasks in a small area. You can create a Virtual Challenge quickly and easily yourself, based on the Tasks that are already in MapRoulette. Here's how you go about this.

First navigate the map to show the area you are interested in by. If you zoom in far enough, you will see individual tasks appear on the map.

You can apply filters to further narrow down the amount of Tasks. For example, you could add a filter to only work on Easy tasks.

Once you're satisfied, you click the 'Work on mapped tasks' button. MapRoulette will ask you to give you new Virtual Challenge a name.

After you set the name, you will be taken to the first random task in you Virtual Challenge. At the top of the Challenge List, you will find a link you can share with others to work on the Tasks together!

Let me know how you used the Virtual Challenge feature and how you would like to see it improved.

Introducing MapRoulette 3

Posted by mvexel on 6 July 2018 in English (English)

This and future diary posts also appear on my blog.

MapRoulette lets anyone contribute to OpenStreetMap by fixing small mistakes on the map. It works like a roulette wheel: once you select something you want to work on, MapRoulette will give you a random task to work on. Once you fix it, you return to MapRoulette for the next task. Do as few or as many as you like. Be careful, people have been known to get hooked on it!

Since 2013, MapRoulette has been used by thousands of mappers to complete well over 1.5 million small tasks to improve OpenStreetMap. We have put all the feedback we have received and lessons we learned into the latest version: MapRoulette v3.

In a series of posts, I will highlight some great new features of this new version. This is the first post. Enjoy!


I heard from some mappers that they couldn't find anything interesting to work on. We spent a lot of time making that easier, by adding different filters.


You can quickly narrow down the list of available Challenges by zooming and panning the map, and selecting 'Within Map Bounds' or 'Intersecting Map Bounds' from the 'Location' dropdown menu. 'Within Map Bounds' will only show you Challenges that only have tasks within the current map view. 'Intersecting Map Bounds' will also show you Challenges that have some, but not all, their Tasks in the current map view. Additionally, you can narrow down the list to Challenges near your current location. This requires allowing browser access to your location.


Challenges are now grouped into Categories, like 'Roads / Pedestrian / Cycleways', or 'Buildings'. You can filter the list of available Challenges by selecting a Category from the 'Work on' dropdown menu.


You can enter any text in the search box, and MapRoulette will only show you the Challenges that have a name or description containing that text.

You can clear any filters you have set with using 'Clear Filters'.

Stay tuned for future posts about the all new MapRoulette 3! I hope you will give it a(nother) try and let me know what you think.

MapRoulette destination challenges: success! (and more to do)

Posted by mvexel on 5 June 2018 in English (English)

A while ago I launched a few challenges on the new MapRoulette (new! you should check it out :)) that have to do with motorway exit information in the United States. Lots of exits around here do not have that information, encoded mainly in destination, destination:ref, destination:to and destination:name tags.

A destination being added based on a Mapillary image

These tags are helpful for navigation users, so they can match what they see on the sign to what they see on their app. Many navigation apps, including OsmAnd, MAPS.ME and Scout use these tags.

Obviously, this information cannot be added from aerial images, but now that there is plenty of street level images from OpenStreetCam / Mapillary to choose from, adding destination info as a non-local mapper becomes much easier. That's why I created these challenges.

  • A task from the Connecticut destinations Challenge *

There have been 11 Challenges so far, for 11 different states. 8 of them are done, but you can still participate in the ones for Connecticut (just posted!), Florida and Pennsylvania.

See the wiki on destination for detailed tagging guidance. Happy mapping!


Posted by mvexel on 4 June 2018 in English (English)

I was going over unnamed 'main' roads in my area using this Overpass query in JOSM:

Most of the time I can use the TIGER overlay to add the missing names. Sometimes I stumble upon a way that should have been tagged as a roundabout or a link (and those usually do not have a name tag). There are some cases when a mapper has added a newly built road from survey or aerial images that does not appear on TIGER yet:

It would be useful to remind myself and others to take some street level imagery there. So I started adding fixme=streetlevel tags to these ways. Perhaps this can be picked up by OpenStreetCam and Mapillary to add to their apps so people can remember to drive there when they are in the area. Extra points maybe?

update there is already the more generic fixme=survey which could also be used, however, for some cases you would specifically like street level images. The few fixme=survey that I found in a quick search in the western USA were mostly trails and paths, which are not the main use case for street level platforms (you can capture them of course).

Creating a quick Survey Kit with Overpass Turbo

Posted by mvexel on 2 June 2018 in English (English)

The weather is nice and I want to go out mapping a little later. It would be nice to have a file and map with things that I wanted to check. Today I will use Overpass Turbo, a great web interface to the Overpass API that gives you all the tools you need to create a quick Survey Kit that you can take with you: a map you can print, and a GPX file to put on your phone or GPS receiver.

Let's say I am interested in businesses that have no opening hours so I can go and add those while I am out. This is a query that would give you exactly that. It is probably not complete and could maybe be simpler, but it is quick for small areas and it does what I need :)

I run this query on a commercial / retail area near my house:

I can then export this as a PNG map to print

And as a GPX file I can put on my Garmin:

And I'm ready to roll!

OpenStreetCam sign detection code and training data open sourced

Posted by mvexel on 16 May 2018 in English (English)

Telenav created and hosts OpenStreetCam, as many of you know. OpenStreetCam now has well over 130 million images contributed in large part by OSM mappers (thanks!). We already integrate the images themselves with JOSM and iD.

About a year ago, we started an internal initiative to apply machine learning to detect important features such as signs that are captured in the images. While we haven’t rolled that out at scale yet, you can already see the results in some US metro areas such as Salt Lake City, Detroit and Dallas / Fort Worth, using the latest version of the OpenStreetCam JOSM plugin. The goal is to make mapping sign content much easier and quicker. You can, for example, filter speed detected speed limit signs to see only the ones where the way in OSM does not have this speed limit yet.

So far, the technology behind this has been internal to Telenav. This is changing today.

Starting today, you can see, download, and contribute to the source code that powers our sign detections from Github. In addition, we’re releasing a training set and a test set of 45000 images manually annotated by our map team with more than 55000 signs in 23 different classes such as: traffic signals, stop signs, speed limits and turn restrictions. You can use these data sets to run your own detection improvements. Perhaps you want to detect benches? Bus stops? Storefronts? Be our guest ☺️ We are happy to add your improvements to the OpenStreetCam platform if they are useful to OSM.

We are also running a competition to celebrate this open source release. If you think you have what it takes to improve our existing detections meaningfully, I encourage you to enter! The competition runs until August 17. There is a $10,000 prize for the winner!

Finally: we do not have any plans to automatically add any of this detected information to OSM. Any improvements will always be made manually by mappers through the existing JOSM plugin, iD integration (coming) and MapRoulette.

If you're interested, there was also an official press release announcing this.

Missing Roads from ImproveOSM now also on MapRoulette

Posted by mvexel on 24 April 2018 in English (English)

Spanish language version

ImproveOSM is my employer Telenav's effort to process billions of GPS points from our users and partners into actionable tasks for mappers. We currently detect missing turn restrictions, missing or wrong one-ways and missing roads. The easiest way to work on these tasks thus far was to install the JOSM plugin.

Now that we have a new version of MapRoulette, I thought it would be nice to make some of these tasks available through MapRoulette as well. This makes it a bit more manageable, because we have 80.000 missing or wrong one-ways, almost 300.000 missing turn restrictions, and almost 1.6 million missing road tiles.. To break that down, let's start with a country-by country effort to add missing roads. I created a challenge for Colombia that you can find here. Let me take you through the process of solving a missing roads task. I use JOSM for my example. You can use iD as well, but then you can skip the steps that involve the JOSM plugins.

1. Install the JOSM plugin

If using JOSM, open the plugin preferences and search for ImproveOSM. Install it and restart JOSM. This will give you three map layers for the different types of tasks. I set the opacity for the missing roads layer lower, because the tiles can make it hard to see the imagery.

2. Pick a Task

Go to the challenge and click 'Start'. You will then be taken to a random task.

3. Complete the Task

The marker for the Task in MapRoulette points to the center of a ImproveOSM missing roads tile.

Sometimes the missing road is not exactly at that location. You can make sure by clicking Edit (make sure you have JOSM running and remote control enabled) and inspecting aerial imagery. You will also see the ImproveOSM tile or tiles used to create the MapRoulette task.

After adding the missing roads (and other things that you see missing or need editing), you can upload your edits. You will notice that MapRoulette has automatically added an appropriate changeset comment for you.

4. Resolve ImproveOSM tiles

Before you switch back to MapRoulette, take a few seconds to activate the ImproveOSM missing roads layer, selecting the tiles affected, and click 'Solve' in the ImproveOSM panel. You can drag to select multiple tiles easily.

5. Repeat

You can now return to MapRoulette and click 'I fixed it' if you added the missing roads. If there was no appropriate aerial imagery, or you weren't sure what to add, you can click 'Too difficult / couldn't see'. In case the roads that ImproveOSM thought were missing were already added by another mapper in the mean time, select 'Already fixed'.

Now you can return to step 2 and continue adding missing roads. Happy mapping!

Want more?

If you would like to see a MapRoulette challenge for your area, please contact me!

New version of OpenStreetCam JOSM plugin with sign detections

Posted by mvexel on 4 April 2018 in English (English)

The Telenav OSM team just released a new version of the OpenStreetCam JOSM plugin. The major new feature is the ability to show and manipulate street sign detections. Images in only a few areas are currently processed for sign detection, so it's not very likely that you will see anything yet, but that will change over time as we catch up processing over 140 million images.


To enable detections, right-click on the OpenStreetCam layer in the Layers panel, and check 'Detections' under 'Data to display'. You can filter the detections by the following criteria:

  • Not older than -- show only detections (or images) from that date or newer.
  • Only mine -- show only detections / images from my own OSM / OSC account.
  • OSM Comparison -- show detections based on comparison with OSM data:
    • Same data -- Only show signs that have corresponding tags / data already mapped in OSM
    • New data -- Only show signs that do not have corresponding data in OSM and need to be mapped
    • Changed data -- Only show signs that have existing tags in OSM but the value is different (for example a 50 km/h sign and the OSM way is mapped as 60 km/h)
    • Unknown -- No match could be made between the detected sign and OSM data
  • Edit status -- show detections based on manually set status of the detection:
    • Open -- new detection, status not changed yet
    • Mapped -- manually marked as mapped
    • Bad sign -- manually marked as a bad detection
    • Other -- other status
  • Detection type -- show only signs of the selected types.
  • Mode -- Show only automatic detections, manually tagged detections, or both.

For the filters OSM Comparison, Edit status and Detection type, you can select multiple values by using shift-click and command/ctrl-click.

In the main editor window, you can select a sign to load the corresponding photo, which will show an outline of the detected sign. If there are multiple signs in an image, you can select the next one by clicking on the location again. (This is something we hope to improve.)


In the new 'OpenStreetMap detections' panel, you can see metadata for the detection, and set the status to Mapped, Bad Detection, or Other. By marking signs that are not detected correctly as Bad Detection, you hide them from other mappers, and we will use that information to improve the detection system.

The plugin is available from the JOSM plugin list, and the source is on Github.

New MapRoulette beta

Posted by mvexel on 28 March 2018 in English (English)

Spanish language version here

Hi all. I want to introduce the new MapRoulette version and invite you to try it. It is currently in beta and feedback and ideas for improvements are very welcome. This information also appears in the wiki section of the MapRoulette GitHub repository. You are welcome to submit issues there. I am looking forward to your feedback!

MapRoulette is a micro-task web tool for OpenStreetMap. It gives you small Tasks you can complete in under a minute to improve OpenStreetMap. Anyone can create groups of tasks, called Challenges, that the community can complete together.

This is the third major version of MapRoulette. The website has been completely redesigned and contains a lot of new features compared to the last major release.

MapRoulette 2 and 3 side by side

Here are some of the most visible new features.


Better ways to discover Challenges you are interested in has been the single most requested improvement. We have spent a lot of time thinking about this, and listening to your feedback. We think you will really enjoy the new ways MapRoulette offers to discover interesting Challenges for you to work on.


Challenge authors can now assign a category to their Challenge, such as Roads, Buildings or Land Use. You can use these categories to quickly narrow down what is interesting to you.


MapRoulette 3 features much improved location based filtering. You can limit your Challenge search to the current map view as you zoom and pan around, and can start the map on an area surrounding your Home Location that you've setup in your OpenStreetMap settings.

Free text

You can use the free text search field to narrow down the list of Challenges to match any text you enter. MapRoulette will search Challenge titles and descriptions for you.

Challenge List

A list of Challenges that match your filter results is now always visible on the left side of the MapRoulette window. It will update in real time as you select filters from the drop down menus, use the free text field, and pan and zoom the map.

Map Display

MapRoulette will now show you where the Tasks in a Challenge are located when you click on a Challenge in the list. As the Task information loads, MapRoulette will first display a bounding box to give you a rough idea. When the Task locations are loaded, you will see them on the map. If there are many, they will be clustered. Zooming in will then show you individual Tasks. You can click on a Task to work on it.

Working on Tasks

MapRoulette now gives you more freedom to decide how you want to work in MapRoulette.

Random or Nearby

The name MapRoulette suggests an element of chance. Tasks within a Challenge used to be served completely at random. This meant that you jump around the map as you work on Tasks. Not everyone appreciated this. We received a lot of requests to offer a way to work on Tasks in a specific area. MapRoulette now offers this. After starting a Task, you can decide if you want your next Task to be one nearby or a random one from the same Challenge. MapRoulette will remember your choice for that challenge.

To change this setting while working on tasks, look for the Random / Nearby switch in the More Options area.

Tracking Tasks

MapRoulette now lets you track a Task. This is useful if you want an easy way to come back to a Task later. When you track a Task, it will be added to the list of tracked Tasks in your Profile page.

To track a Task, click the Track switch in the More Options area.

Saving Challenges

If you like a particular Challenge, MapRoulette now offers an easy way to save it. When you return to MapRoulette, your saved Challenges will always appear at the top of the list.

To save a challenge, click on the title to reveal the details, and then click 'Save'. You can 'Unsave' in the same way.

Working Together


MapRoulette lets you comment on individual Tasks. You can use this feature to let other mappers know why you skipped a Task or marked it as Too Hard, for example. The Challenge author will also be able to review comments, perhaps to make improvements to the Challenge. So you can use comments to let the author know your feedback as well.

To comment on a Task or review previous comments, look for the comment field below the Task instruction.

Virtual Challenges

A new concept in MapRoulette is the Virtual Challenge. This is still very much a work in progress and something we would really like your feedback on. A Virtual Challenge is an impromptu Challenge you can create yourself out of the available Tasks for the area you are interested in. This lets you systematically solve all MapRoulette tasks, across Challenges, in your area. This can be fun and useful for a Mapping Party!

To create a Virtual Challenge, go to the main Challenge list view by clicking on Challenges in the top menu. Next, use the map to zoom in to the area you are interested in. When zoomed in far enough, you will see that individual tasks are loaded and displayed on the map. You will also notice that a button 'Work on mapped Tasks' appears at the top of the Challenges list. By clicking this button, you create a Virtual Challenge that consists of all the currently visible Tasks. If you want, you can use the filters to narrow down the Tasks further before you create your Virtual Challenge.

Social Sharing

When working on a challenge, it's now easy to share a link via email or on selected social networks using the social sharing area near the bottom of the task sidebar.

Go here to try the new version:

Trunk in a funk

Posted by mvexel on 6 October 2017 in English (English)

Here is how Wikipedia defines "Trunk road":

A trunk road, trunk highway, or strategic road is a major road, usually connecting two or more cities, ports, airports and other places, which is the recommended route for long-distance and freight traffic. Many trunk roads have segregated lanes in a dual carriageway, or are of motorway standard.

'usually'.. 'many'.. Adverbs that serve to muddle the definition: I still don't know whether a specific road can be classified as a trunk or not.

The OSM wiki has this to say:

Use highway=trunk for high performance or high importance roads that don't meet the requirement for motorway. In different countries, either performance or importance is used as the defining criterion for trunk – see #International equivalence and Highway:International equivalence for guidance on road classification in different countries.

Hmm. Equally noncommittal. But there are reference to places where more specific references are to be found. I am interested in the United States. So let's look there. The 'International Equivalence' section on the highway=trunk page says:

Surface expressway: A relatively high-speed divided road (at least 40 MPH with a barrier or median separating each direction of traffic), with a limited amount of intersections and driveways; or a major intercity highway. This includes many U.S. Highways (that do not parallel an Interstate) and some state highways. Wikipedia reference

..whereas the separate 'International Equivalence' page says for trunks in the United States:

Limited access highway with occasional grade level intersections, or major intercity highway where no motorway exists.

Not precisely the same, but I am starting to see a pattern. The definition of trunk, according to the people who wrote the wiki pages, seems to be a mix of technical and functional road classification:

  • Technical: Designed for speeds > 40 MPH, limited at-grade intersections.
  • Functional: Major inter-city highway where no motorway exists.

Let's try and apply this to some major roads in Utah that I know well and are currently at least partly marked as trunk. (This Overpass query shows all trunk ways in Utah.)

US Highway 6 between Spanish Fork and I-70, currently marked as trunk in OSM. This is a two lane road with a speed limit of 65 MPH, with some exceptions in places. It is the main connection between the Wasatch Front and southeast Utah and southwest Colorado. There is no freeway alternative. **Conclusion: proper trunk.

State Route 154 or Bangerter Highway as it is known locally. Currently marked as trunk but some stretches are marked motorway as well. It is a 4-6 lane divided highway. Some sections have at-grade intersections (Continuous Flow Interchanges among them) but they are spaced pretty far apart. SR 154 is not a major inter-city highway, and there is a reasonable freeway alternative available. However, SR 154 does serve an important connector function between cities and towns west of Salt Lake City and the SLC International Airport. Conclusion: trunk is OK, but motorway sections should be downgraded.

US Highway 89. Currently only marked trunk between Farmington and I-84, where it meets the technical (if not the functional) definition of trunk. Most of the rest of US-89 is two-lane road with a speed limit of 65 or 70 MPH, with local exceptions. If you look at it purely from a functional perspective, only the stretch between Brigham City and the WY border in the North, and the (long) stretch from Provo south to the AZ border can be considered trunk. The section actually marked trunk currently is not part of either of these two. To my mind, the sections that serve important long distance connecting functions should be trunk as well. Conclusion: more sections should be trunk.

Looking at a few of the roads I know and their current tagging in the context of the current wiki definitions, my overall conclusion is:

A road should be tagged trunk in the United States if either of the following conditions are met:

  1. The road is designed for speeds > 50 MPH and has limited at-grade intersections.
  2. The road is a serves an important inter-city connector function, and there is no freeway alternative.

Small stretches where condition 1) is not met, for example a reduced speed limit in a built up area, should be tagged trunk to maintain a continuous classification.

Pretty? No. Works for me? I think so. What do YOU think?

Mapping Center Turn Lanes in the United States

Posted by mvexel on 3 October 2017 in English (English)

When I moved to the United States six years ago, center turn lanes were a new thing to me. Two Way Left Turn Lanes (TWLTL) , as they are officially called, make traffic safer on busy roads where left turns are made frequently, by offering a dedicated lane for left turns:

design Source: MUTCD

When I first started to map these lanes, there was no documentation on the OpenStreetMap wiki on them, so I just started to map ways that have them with center_turn_lane=yes, thinking that I'd revisit them later if the community came up with more sensible tagging scheme.

In 2012, infamous US mapper NE2 created a page dedicated to TWCTL, adopting the British spelling centre_turn_lane=yes. There are around 6000 uses of this tag, most of them in the United States. The page was created without much if any discussion in the US community: there is only one reference to it on the talk-us mailing list[1].

Since 2012, more elaborate tools and tagging schemes have emerged to map lane configurations. I particularly like the Turn Lanes Editor JOSM plugin which, together with the Lane and Road Information paint style, offers an intuitive and visual way to add lane details to ways.


As you can see, when a two-lane road with a TWLTL is tagged using the plugin, the map paint style offers the correct interpretation. The tags on this way would be as follows:

lanes=3; lanes:forward=1; lanes:backward=1; lanes:both_ways=1; turn:lanes:both_ways=left

Even though this looks much more complicated than just centre_turn_lane=yes, the plugin makes it straightforward to map (it even remembers recently used configurations so you can easily apply to other ways) and it uses the generic lanes tagging schema that is already in wide use, and allows for tagging even the most complex lane configurations.

TWLTL have been a topic of discussion in the Telenav mapping team. We have been adding a lot of lane configuration details in Detroit and Phoenix. For now, I gave the team the following guidance:

  • For ways that don't have TWLTL tagging yet, use the plugin and the generic lanes / turn:lanes schema.
  • Where (local) mappers have already added centre_turn_lane tagging, leave it alone.

I would rather have one consistent tagging style for the United States (and other countries where TWLTLs are common. I would prefer to use the lanes / turn:lanes tagging for that. What do you think?

[1] The OSM mailing lists are notoriously hard to search. I used wget -r -np -l 1 -q -A gz && find . -name \*.gz -exec gunzip {} + && find . -name \*.txt -exec cat {} + | grep centre_turn_lane

Many Mappy Minutes

Posted by mvexel on 28 September 2017 in English (English)

In my last diary, I announced that I would be restarting the virtual Mappy Hour for US / North America mappers. We had our first edition tonight and I enjoyed it very much.

Around 10 people participated. Kate Chapman from OpenStreetMap US joined us to talk about the upcoming State of the Map US conference, which is only four weeks away. We chatted about a variety of interesting topics: welcoming new members, how people become interested in OSM, membership of the OSM Foundation, hack weekends, how to best announce OSM events, and many more things.

The plan was to have this be a mappy 'hour' but we ended up spending two hours talking. We came up with a new name: Many Mappy Minutes. We decided to organize it about once a month. The next Many Mappy Minutes will be on November 15, at 5:30pm Pacific Time. Zoom worked well, so we will continue to meet on there: . You can also dial in from a normal phone. I hope to talk to you then!

OpenStreetMap US Mappy Hours Reboot

Posted by mvexel on 18 September 2017 in English (English)

A few years ago I started a bi-weekly video chat for US mappers, called Mappy Hours. They were fun and varied, with topics ranging from tagging discussions to a presentation about OpenHistoricalMap and many things in between.

Then we all got busy and the Mappy Hours stopped. I was recently reminded about them on the OSM Slack channel, and I thought it would be nice to restart them. So here are the details of the first Mappy Hour:

Wednesday September 27 at 5:30pm Pacific Time

We used to use Google Hangouts, but there were problems with that: a limited number of video participants, you couldn't call in, plugins.. There is no perfect solution but I have had success with Zoom so we will try that. You can either download the Zoom client or call in using your phone.

Zoom link

There are local dial in phone numbers for many countries.

The topic for the first Mappy Hour will be State of the Map US. What are you looking forward to? Do you have a presentation you want to promote? Do you have ideas to make the conference even better than previous years? Let's talk! Even if you are not planning to attend SOTM US, I invite you to attend: there will be plenty of time to talk about other things as well.

MapRoulette newsletter

Posted by mvexel on 13 June 2017 in English (English)

I am still sending out (almost) monthly MapRoulette newsletters. The latest one just went out! If you are interested in receiving them you can see the latest newsletter and subscribe here.

How would you map this?

Posted by mvexel on 11 May 2017 in English (English)

I am trying to figure out mapping complex intersections and I am a little stumped :) To completely represent all possible lanes and turns in an intersection, you would need to define:

  1. The lane layout (turn lanes, through lanes)
  2. The lane connectivity (which lane connects to which at the far end of the intersection)

If I asked you to map this intersection completely, how would you do it? Which (combination of) turn / lane tagging schemes would you use?


(If you're interested, this type of intersection is a CFI or continuous flow intersection.)