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, 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!


9 thoughts on “The TIGER versus OpenStreetMap Battle Grid, improved!

  1. This is pretty neat. I’ve clicked around a bit and in a lot of cases the bright squares are actually the ones where users have done a lot of work, thereby accounting for the difference to the TIGER data. I wonder if you could take into account another metric, something like number of non-import changesets, to automatically filter those out.

    1. Good point. We may look at the average age or version of the OSM ways, or the number of unique editors for that cell, or a combination of that, to say either ‘this is probably bad TIGER’ or ‘this is probably bad OSM’.

  2. Just thought I would note what was going on in St Louis. Those roads (and the houses that went with them) used to be there and were there for decades as part of the Carrollton neighborhood of the city of Bridgeton.

    And then the airport bought the entire area out to build their new runway, unfortunately uprooting an entire community in the process. The new runway build started in 1998. By the time it was completed in 2006, TWA had gone bankrupt and closed its hub in St Louis. American Airlines had also shut down much of their St Louis operations, and the Air National Guard left.

Comments are closed.