Visualizing Notes added to OpenStreetMap through Craigslist

Posted by dalek2point3 on 13 June 2014 in English (English)

One of the most prominent users of OpenStreetMap is Craigslist. Craigslist users often use OpenStreetMap to indicate the location of the house / item they are selling. When they dont find the street they're looking for -- Craigslist users have the option to submit a note to the notes system.

I've found these notes to be useful, quite often containing information about subdivisions that are missing from the map. I wanted to visualize all the notes submitted through this system. Even though Craigslist does not submit notes using a dedicated URL (although I think they should!), they use a peculiar notes system and notes from Craigslist almost always look like this one:

bounds: (38.0118,-121.943 - 37.9966,-121.9013) Map is missing data here. Freshwater Court in Pittsburg CA is not showing up

Notice -- how they begin with "bounds". This suggests that using the OSM Notes API to search for the text "bounds" should give a reasonably accurate picture of notes from the CL system.

I wrote a script to use the API to get this data, and parse it into a CSV ready for visualization -- you can check out the code on github and visualized the 2980 notes that I found using Cartodb. Each dot contains a link that will take you to the Notes page where you can read the full text of the comment.

And this is what we get! Click on the image to be taken to the CartoDB page (I cant figure out how to embed IFRAMEs in diary entries). You can even download the raw data here

Click here to explore this map map

Location: East Cambridge, Cambridge, Middlesex County, Massachusetts, 02114, United States of America

Comment from JBacc1 on 13 June 2014 at 07:41

Nice. But you omitted to say how you got the raw notes list to work with… I would be curious to find out! JB.

Comment from dalek2point3 on 13 June 2014 at 15:01

I got the data from the OSM Notes API. You can check out the program here: (And you'll also find both xml and csv versions of the data there).

Comment from skorasaurus on 18 June 2014 at 17:57

Nice work. Is there a way to display only notes that are still open? Have you thought about implementing this?

Comment from dalek2point3 on 20 June 2014 at 06:43

Just updated the cartodb visualization to show different color codes for open / closed notes! The closed ones are in green and the red ones are still open. looks like the midwest needs some work!

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