Tagurban data visualization

Best ways to present bicycle crash data

I started some preliminary work on my crash reporting tool. I haven’t written any code, but I’ve been working on the logistics of analyzing and presenting the data to the public.

I obtained bicycle crash data for 2009 from the Illinois Department of Transportation’s Division of Traffic Safety. I’m not able to distribute raw data (you’ll have to ask for it yourself) and Illinois statutes prevent me from distributing personally identifying data (but it’s really hard to know what this is). In the meantime, based on Ben Sheldon’s suggestion, I loaded some of the data into a private Google Fusion Table that instantly maps geocoded data (it can also geocode the data for you).

Richard cautions me about way I choose to present data. I need to choose terms and descriptions carefully to avoid misinterpretations. Pete from the Boston Cyclist’s Union recommends against accepting self-reported data. I’ll be taking their advice into consideration as I move forward.

You see in the map (top) that a lot of crashes happen on Milwaukee Avenue (above). That’s where a lot of people ride (over 3,000 in 24 hours in the fall).

I have not begun to review the narrative details in the crash reports. Actually, they’re not very narrative because they’re fixed responses – no free writing allowed. And not every record represents a collision (meaning a crash with at least two parties). Many are self-crashes (is that a legit phrase)?

I’m not sure exactly what story I want the data to tell so it will probably be a while before I make anything public. One of my favorite geographic information books, Making Maps, talks about the endless ways maps can be designed and portrayed and that each tells a different story. It’s best if I know the story (a goal) ahead of time.

Finding geographic information about Chicago and elsewhere

The City of Chicago’s GIS division of the Department of Information and Technology as well as the Zoning Department provide copious data on boundaries, crime, zoning, etc… And I’m not talking about a library of PDF files. You can’t analyze or manipulate or calculate using PDF – I’m talking about data sets, shapefiles, or aerial photographs.

You can start here on the GIS website.

 The Chicago Police produce the CLEARMAP website. And even the Bicycle Program throws down with bikeways and bike parking data. Check out Wicker Park’s Center for Neighborhood Technology and its urban data visualization websites, like their Housing and Transportation Affordability Index.

List sources for your city’s data in the comments. Milwaukee has its own Spatial Decision Support System called COMPASS. Here’s Maricopa County’s (Phoenix, Mesa, Tempe) ArcServer-based online GIS website.

Check to see if EveryBlock has started data mining your city. They began their news collection and repackaging efforts in Chicago, naturally 🙂 They are the first organization to find a new way to present Chicago’s bike rack installation info.

UPDATE: The community at OpenStreetMap has a huge list of datasets available for cities and places around the world.

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