Wednesday, January 23, 2013

Too Much of a Good Thing

What makes OpenStreetMap great? Well there may be multiple answers from different people. But one thing is certain: Our geodata is awesome. I mean it is kind of the reason that we exist. So more is better, right? We are, after all, trying to map the entire planet.

But it turns out, there can actually be too much of a good thing. One of my first encounters with such a situation was while doing some fixing up of imported TIGER data somewhere out west. I came across this:

Notice the scale. We are looking at a little over 100 meters of country highway and there are over 300 nodes in this image. This is obviously beyond ridiculous and I can assure you that this particular instance was cleaned up long ago and those nodes met their appropriate end in a special level of /dev/null.

But this is not an isolated incident. I keep coming across such over-noding. So I decided to use my local planet database (which I previously blogged about setting up) to try and find out how much this really happens and where such things come from.