What’s up with this?

Hi all,

This blog still gets quite a few Google hits, and I have not written on it since 2013, so I thought I’d point you to some places where you may find my more current writing.

I work at Telenav on OSM related projects. My colleagues and I publish about things like OpenStreetCam and ImproveOSM on our blog, OpenStreetMap @ Telenav.

My OpenStreetMap diary gets infrequent attention.

I have a personal page with some photography, cooking random ideas and, again, some OpenStreetMap stuff from time to time.

I am on Twitter as well.

The best way to get in touch is by emailing m@rtijn.org. I look forward to hearing from you.

The TIGER versus OpenStreetMap Battle Grid, improved!

I reposted this story on my OpenStreetMap Diary. I think the diaries are a great asset to the OpenStreetMap community and they are not used as much as they should. I will try and post more of my OpenStreetMap-related stories there (as well).

If you follow the blog at openstreetmap.us, you will have heard about the Battle Grid. It is a map that shows you where recent TIGER data is different from OpenStreetMap data. Because TIGER has improved a lot over the years, and has kept up reasonably well with new road construction, a big difference between TIGER and OSM tells us that OSM likely needs some love. Here is how the battle grid looked until today:


Cells with a lot of difference between TIGER and OSM are brighter, and as a simple way of prioritizing the cleanup and update work, I colored the cells that are within a Census CDP orange, and the rest green.

As of today the Battle Grid will look like this, instead:


The brightest cells are still the most different. What is new is a color spectrum ranging from green to red, indicating how many people drive in and through each cell. This is based on Telenav logs. Because lots of people use Telenav apps such as Scout every day, it should be a fair representation of interestingness.

Let me show you a few examples of bright Battle Grid cells to whet your appetites.

Here’s a bright red cell in Greenville, NC:


Look at this! Missing subdivisions, and poorly aligned streets. A mess!


If I weren’t writing this blog post I’d be fixing this…

The green cells are usually no less, ehm, interesting. Here’s one in Saint Louis, MO:


I guess someone had a plan for this area, and the someone with more money / power came along with a different plan, and nobody ever told Census:


What I generally find is that the bright cells on the fringes of urban areas are most gratifying. These usually represent either poorly aligned OSM data, unmapped new subdivisions, or a combo of both.

Speaking of fringes, I think Atlanta has a great visual Battle Grid story:Image

The city itself is well mapped with very few bright cells. (And whatever there was is mostly black, so people have already marked them as done.) The fringes still show a lot of, well, let’s call it mapping potential!

What are your favorite Battle Grid finds? Share them below!

New MapRoulette challenge: Lane Counts

MapRoulette is overdue for a new challenge, and we have one that should keep us busy for a while: adding numbers of lanes to the main roads in N-America. This information would be great to have for advanced visualization and transportation analysis purposes. And a lot of it is already there, so let’s just make it complete.

The challenge works as follows: You fire up MapRoulette as usual by going to maproulette.org. You are presented with one OSM way somewhere in North America that does not have a lanes=* tag. (We only care about secondary and higher to keep things useful and manageable, and we’re starting with the motorways and moving down, so you should see only motorways at first.)

Screen Shot 2013-04-06 at 1.26.55 PM

If you want to fix this road, click on ‘Edit in JOSM’ and wait for the way to load in JOSM. Make sure you have JOSM running, otherwise the button won’t work.

Screen Shot 2013-04-06 at 1.30.26 PM

To actually see the number of lanes of this road, you may need to zoom in a little.

Screen Shot 2013-04-06 at 1.32.36 PM

Aha! This road has two lanes. So we go ahead and add that as a tag to the road. Hit Alt-A (Option-A on a Mac) or click ‘Add’ in the Properties pane:

And enter the information in the tag dialog:

Screen Shot 2013-04-06 at 1.49.03 PM

Click OK.

Now upload your change, adding a brief changeset comment in which you should mention you used MapRoulette – for example by adding #maproulette:

Then, return to MapRoulette and indicate that you have fixed the problem!


Not all cases are this simple. There’s a few things you need to look out for.

In some cases where the amount of data to load into JOSM would become too big, JOSM will only load the actual way that requires your attention, not the data for the entire area.

Here’s an example:

Screen Shot 2013-04-06 at 2.11.59 PM

If you zoom in and deselect the road, you can see that this road is marked as oneway.

Screen Shot 2013-04-06 at 2.16.46 PM

Because this looks like a dual carriageway road from the aerial imagery, there is probably another OSM way representing the other side of this road. If unsure, confirm by loading more data.

In these cases where only the actual way is loaded, you should also avoid moving or deleting nodes from the way, as these nodes may be shared with other ways you cannot see. Before you make any such changes, load more data.

Also, only enter the number of travel lanes and do not include merge lanes. Here’s an example:


Screen Shot 2013-04-11 at 3.58.11 PMThe right lane is a merge lane, and does not count towards the main road lane count. So in this case the way would get lanes=3. You can see that it’s a merge lane by looking at the context (pan around and you will see the ramp) as well as by the difference in lane markings.



OpenStreetMap US Virtual Mappy Hour

The new OpenStreetMap US Chapter board has been using Google+ Hangouts for meetings, and it has been serving us well. Hangouts are like conference calls, but you can see each other and that is a huge advantage over just talking on the phone.

Google offers a more public variation on this theme called Hangouts On Air. Those are basically Hangouts anyone can tune in to via YouTube. Up to 9 folks at a time can hang out, all others get to watch. We (board) thought it would be cool to use this as a new discussion platform for the OpenStreetMap US Community. So we are going to try this out and host our first OpenStreetMap US Virtual Mappy Hour, next Monday, November 12, at 5:30PM Pacific, 8:30PM Eastern.

The link will be posted on the Mappy Hour Google+ Event page on the OpenStreetMap US Chapter Google+ page for details and come hang out (and likely iron out some kinks as we figure this out) next Monday.

As for discussion topics, I would love to talk about how to guide the temporary invasion of armchair
mappers in the upcoming Operation Cowboy. If there’s interest, I could also talk about what the board has been up to. But it’s not a formal meeting, so let’s just see where (and how long) it goes.

For those without google accounts: The YouTube channel is supposedly open to the public. If you want to say something, we can dial you in. Let me know in advance if you want me to do that.
Finally, please be aware that a recording of the hangout will remain available on YouTube for anyone to watch at any time.

See you at the Virtual Mappy Hour!

Un-Zorro-Tron – The 90 Second Video

Folks tell me that the Un-Zorro-Tron is less intuitive than its predecessor the Remap-A-Tron. So here is a 90 second video that shows you what a Zorro way is and what to do about them.

UN-ZORRO-TRON 90 sec instructions from rhodes on Vimeo.

If you don’t have 90 seconds, here’s a 60 second video:

If you don’t have 60 seconds, a picture may tell you more than 1,000 words:

Google Maps and OpenStreetMap Data Views – Find The 10 Differences

Google Maps had The Atlantic over for a chat about how they work up their ‘deep map’ from various sources. It’s interesting to read about how Google invests incredible amounts of money and manpower to try and do the best job possible of capturing ground truth without people on the ground.

The article contains some ‘data views’ of Google Maps data in various stages of being worked up. I don’t know if it’s actual screenshots of an editing environment, but regardless, it’s an interesting peek behind the scenes that I had not had before.

This is from the article:

The Google Maps editing environment. Source: The Atlantic

This is about the same area loaded into the OpenStreetMap desktop editor JOSM:

The same area in the OpenStreetMap editor JOSM

Now you can look long and hard to try and make out ten or maybe a hundred differences in the data, but there’s one difference between these two views that reaches much deeper. The data behind Google Maps you will never get to see, let alone touch. The data in OpenStreetMap on the other hand is there for anyone to download, use, make great products out of and, most importantly, edit and improve. That difference marks a cardinal characteristic of the Google Maps platform that the article failed to raise. Consider that itch scratched.

Submit your session proposal for SOTM USA

It’s been a while folks. I have been working on some exciting OpenStreetMap related things that I am eager to report on, but preparing to teach my first academic course has taken up a lot of my time lately. By the way, the course is an advanced GIS course, and it’s fully online, so if you want to brush up your GIS skills, you should enroll! Drop me a line if you’re interested. But now on to relevant matters!

The deadline for session proposals for the State of the Map USA conference is on Friday, August 31, so submit your session idea soon. The conference will be made up for talks by community members on everything from tools and techniques to working with and contributing to OSM data to showcases of it in use by companies, governments, nonprofits, and everybody to bigger picture discussions of where OSM should be moving in the future.

The State of the Map USA conference will bring together people working with, adding to, and advocating for OpenStreetMap. Our community is filled with people doing interesting, cutting edge, and important work. This is your chance to share it with us all.

You can submit your session proposal here – we just need 200 words or less about what you want to talk about. If you have questions, email me or hit us up on Twitter at @sotmus.