Missing Roads - The Missing Manual

Posted by mvexel on 2 October 2015 in English (English)

Earlier this week, we released the Missing Roads project. Using its tools, every OSM mapper can now easily find roads that are not yet in OSM, based on our years of collected global GPS data from Scout users.

A lot of you have already had some fun with the JOSM plugin and the web tool. I received interesting reports about important roads you have been able to add. But also some questions about how to optimally make use of the Missing Roads tools. So I thought I might write up a Missing Roads Manual of sorts.

Missing Roads consists of two tools: a web tool and a JOSM plugin.

The Web Tool

The web tool is a convenient way to locate missing roads in an area. You can quickly get a sense of the distribution of the missing roads data.

If you zoom in far enough, you can also see the individual tiles.


Colors of tiles and traces

You will notice that there are different colors for both the traces and the tiles themselves.

The blue tiles haven't been touched yet. These are the 'open' tiles.


The green tiles are the ones that you marked as solved. Yay!


The red tiles are marked as invalid.


Looking at the colors of the traces, you will notice purple, yellow and black trace colors.

The purple color means these are probably actual roads.


The yellow trace color means we think it is people looking for parking.


The black traces are 'mixed': some people were driving faster, some slower, so we are not so sure.



You can filter the results both by tile status and by (probable) type.




The web tool is mainly meant for browsing. You cannot change the status of the tiles from the web tool at this time. This can for now only be done in the JOSM plugin. We do however provide convenient links to edit the current map extent in JOSM and iD.


Aerial view

To quickly check if there are actually roads in the area, you can switch between the default OSM layer and an aerial imagery layer, courtesy of ESRI.


JOSM plugin

The main interface to the Missing Roads data is our JOSM plugin. It offers a similar browsing functionality as the web tool does, but with a slightly different visualization:


The red dots represent clusters of missing road tiles at lower zooms. When you zoom in you see the actual tiles and the point clouds.


Installation and activation

Install the Missing Roads plugin the familiar way, through the JOSM plugin preference pane. When installed, and after a quick JOSM restart, you should see the MissingRoads layer and panel.

Missing Roads Layer

The layer shows up like any other JOSM layer in the layer panel, and of course on the main map canvas showing you the actual missing road tiles / clusters.


As with any layer in JOSM, it needs to be active if you want to interact with it. So if you want to select tile(s) you will need to activate the MissingRoads layer first.


Missing Roads Panel

In the panel, you can interact with the currently selected tile(s). If you don't see the panel, you should be able to reveal it using ctrl-F3 / cmd-F3.


The panel has three tabs with various bits of information about the selected tile. If you have more than one tile selected, you'll see info about the last tile you selected.

The Tile tab shows basic information about the selected tile.

The History tab shows a history of status changes and comments.

The Have a new idea? tab has a link to the Missing Roads ideas forum. Submit your ideas and bugs there please!

The panel also has a number of action buttons on the bottom. These are for filtering, adding comments, and resolving tiles. I will discuss those features in the next sections!


Similar to the web tool, you can decide which tiles you want to see based on their status and (probable) type.


If you want to clear all filters, you can click Reset.

You can only filter on one status or type at a time.

As a bonus, you can also set a trip count threshold. This allows you to filter out tiles that have a low number of trips passing through them. You can see the number of trips for the selected tile in the Tile tab.


Clicking on the comment button opens the Add Comment dialog allowing you to add a comment to the currently selected tiles for your fellow mappers to see.


If you have multiple tiles selected (using Shift while selecting), the comment will be applied to each tile.


Finally, there are three buttons to resolve the selected tile(s).


The 'lock' button solves a tile and marks it as done.

The 'unlock' button marks the tile(s) as un-done or open again.

The '!' button marks the tile(s) as invalid. Use this if there is not actually a road there.

Color coding

The tiles and the traces have the same color coding as in the web app. To summarize:


  • Blue = Open
  • Green = Solved
  • Red = Invalid


  • Purple = Road
  • Yellow = Parking
  • Black = Mixed

Mapping tips

Imagery layers

Obviously you shouldn't add roads solely based on the traces. You need a secondary source of validation. Most of the time, this will be an aerial image. The default aerial layer in JOSM is Bing. Bing imagery can be a few years old. For some regions, more recent imagery may be available. Look for aerial layers in the JOSM imagery menu. Note that most imagery layers are location-aware: they will only appear in the menu if they actually have imagery for the area you are currently mapping. So be sure to check the imagery menu again if you're editing in an unfamiliar area.

Here is an example where Bing shows no sign of a new road, but a local imagery layer does show it:


Strange traces

We have spent a lot of time looking over the results and tweaking the algorithm to get rid of as many irrelevant traces as possible. But we know there are still strange traces out there. I have been getting interesting reports already of traces from trains, airplanes, and even cranes.


Source: Flickr Commons

I know this can be frustrating. If you find strange cases, please take a minute to report them through the feedback page. And mark them as invalid. Thank you!

Source code

The code for the plugin can be found on GitHub if you're interested.


There are links in the web tool as well as in the JOSM plugin to give feedback and submit ideas. Both links go to the Missing Roads feedback web site. You can also vote on other mapper's ideas there. I look at all incoming ideas together with my colleagues on our OSM team, so be sure your input is heard and very much appreciated!

Also, don't hesitate to just email me at or tweet at me (mvexel). Talk to you soon!

Have fun adding missing roads :)

Comment from stephan75 on 2 October 2015 at 21:28

Hi ... why not including these instructions in the OSM wiki?


Comment from mvexel on 2 October 2015 at 21:35

Because it will take me 5x as long to write this in wiki markup. But why not put a link to here on the page?

Comment from mvexel on 2 October 2015 at 21:37


Comment from Pink Duck on 5 October 2015 at 14:24

There appear to be script errors at in Firefox/Chrome currently.

Comment from mvexel on 6 October 2015 at 15:16

Pink Duck - can't reproduce - could you please email me specifics? >>

Comment from bdiscoe on 16 October 2015 at 07:02

It's working great for me; i added roads it found in a few places. At least one place was quite dramatic, the entire large town of Cortazar, Mexico, entirely missing from OSM; i added just a bit of it.

My only feedback on the plugin is the red circles, they jump around quite oddly, sometimes they just vanish for no clear reason. When i do get one to stay steady, i can zoom in and find the tiles. Perhaps this is just a result of the clustering algorithm being used. In that case, perhaps the clustering could be a little finer-grained (more points, less clustering) so it isn't so jumpy.

Comment from Alan Bragg on 30 October 2015 at 01:05

The tool is working well for me. It was a while before I realized I should also turn on the "New and Missaligned TIGER Roads 2015" imagery in order to add the road names. This could be stressed more in the instructions for people working the USA.

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