WingNews logo WingNews GitHub [2]
top | item 7958598

OpenStreetMap node density map 2014

139 points| lelf | 11 years ago |tyrasd.github.io | reply

51 comments

order
[+] lucb1e|11 years ago|reply
Looks like The Netherlands is one of the most dense countries in the world. I wonder why that is, we (speaking as a Dutch person) hardly seem to use OSM while in Germany it's very popular.

One explanation is the recent addition of the government's address and building data, which gives us close to perfect outlines for every building in the country plus an extra node per address. Or we just have a high number of people per square kilometer regardless of the recent (now almost finished) data import.

Edit: Looks like it's simply our density in general and not this import; last year the Netherlands also stood out while we hadn't even imported 10% yet. From last year: http://www.openstreetmap.org/user/tyr_asd/diary/19549

[+] maxerickson|11 years ago|reply
The buildings have a huge impact. Look at New York, Chicago or San Francisco. They also had building imports and they shine quite brightly.
[+] robin2|11 years ago|reply
My guess is that this might be cycling related; that an area where there's likely to be public-spirited cyclists with GPS devices is well placed to get good OSM coverage.

In support of my theory, I point to Cambridge being a little bit of a hotspot in the southeast of England. (Not so much as Clacton though ... hmmm ... maybe the theory needs some work.)

[+] malandrew|11 years ago|reply
I found the map of greenland fascinating, since there is pitch black internally. Everything is along the coast.

At the lowest zoom level what are geometric lines that criss cross Greenland and the curvilinear lines and rings off the coasts?

[+] analog31|11 years ago|reply
Another interesting note: I would have expected North Korea to be dark, but it's brighter than neighboring China.
[+] ajtaylor|11 years ago|reply
The whole of Massachusetts is brighter than the surrounding states, and grows brighter the closer you get to Boston. I wonder where all that data came from. Was it a corporate or state data donation?
[+] maxerickson|11 years ago|reply
For the state, it's "MassGIS" data. Many of the points are from road center lines that are a lot denser than is typical in OSM, but there is also land use/classification data (like wetlands or whatever).
[+] 3rd3|11 years ago|reply
It would be interesting to see this map adjusted to population density.
[+] lucb1e|11 years ago|reply
Well count the building tags and you got a rough population estimate for any area.
[+] BoppreH|11 years ago|reply
I'm sorry, but I don't see any much use in this visualization. It's pretty, but gives almost no information at the global level, for two reasons:

1) It's not adjusted for population ( http://xkcd.com/1138/ ). They can normalize the data to fix this.

2) The map is ludicrously distorted because of the Mercator projection. Greenland looks bigger than the entire South America, when it should be an eighth of the size. This directly affects the perceived density in each area. Suggestion: if you are using an interactive geographical visualization, why not display a globe?

However, it does look stunning.

[+] laurent123456|11 years ago|reply
That what I thought at first but the visualization is actually useful. For instance, I have the offline OpenStreet map of Germany on my phone, which is about 1GB. In comparison, the map China is about 110MB, despite having a population 15 times bigger. The node density map does actually reflect this kind of differences. I find the difference between Brazil, Chile and Argentina also quite interesting.
[+] maxerickson|11 years ago|reply
There is no claim that the density means anything, so there isn't any need to adjust it for population. I imagine the title "OpenStreetMap node density map 2014" was somewhat carefully chosen, and it manages to say what is shown.

If you read the link that Vik1ng posted, the author seems to be fairly clear that they were just making a pretty picture (and quietly points out the problems with the projection).

[+] Vik1ng|11 years ago|reply
@1 I think the main goal is simply to display OpenStreetMap node density. Nothing more and nothing less. For mappers it's kinda interesting. He did't want to make a map where the most active mappers are.
[+] runlevel1|11 years ago|reply
Interesting how brightly Bakersfield and Fresno glow.

I wonder if it's because the streets are so gridded and therefore not as prone to aliasing.

[+] maxerickson|11 years ago|reply
Each pixel represents quite a lot of area so aliasing probably isn't coming into it.

Bakersfield has a bunch of buildings (which lines up with the theory in my other post in this thread). It looks like imported land parcels make up a lot of the data in the Fresno blob:

http://www.openstreetmap.org/#map=16/36.7805/-119.9009&layer...

(Probably a good idea to turn off the data layer there before zooming out)

[+] dublinben|11 years ago|reply
You can also see the border of Massachusetts perfectly clearly, likely due to the import of MassGIS data. Surrounding states are all much lower density, until you hit Manhattan.
[+] twic|11 years ago|reply
What are the rectangular features in northwestern Canada?
[+] maxerickson|11 years ago|reply
On one side "CanVec" data has been imported and on the other it has not. If you zoom in from here you see all the small streams that are showing up in the visualization:

http://www.openstreetmap.org/way/157650655

That doesn't explain the differences on the imported side, but I guess that could just be more imports vs less imports.

[+] moron4hire|11 years ago|reply
Perhaps satellite or aerial photography.