Category: GIS

Better bike crash map now available for Chicago

I met Derek at a get together for “urban geeks” last Tuesday where he told me he was making a filterable/searchable version of my Chicago bike crash map using the Google Fusion Tables API. It essentially allows you to perform SQL-like queries to show different results on the map than one view. It’s possible to do this yourself if you open the bike crash map in the full Google Fusion Tables interface (do that now).

You can use it now!

New bike crash map, click through to view

Derek’s map has the benefit of great interface to drill down to the data you want. You can select a day, a surface condition, and the injury type. To download the data yourself, you’ll still have to access the full Fusion Tables interface.

Door lane photo and graphic by Gary Kavanagh in Santa Monica, California.

And since the data is the same as my original map, crash reports involving motor vehicle doors are not included. Here’s why doorings are excluded.

Free online GIS tools: An introduction to GeoCommons

Read my tutorial on how I created the pedestrian map with GeoCommons. Read on for an introduction to GeoCommons and online GIS tools.

GeoCommons, like Google My Maps and Earth, is part of the “poor man’s GIS package.” It’s another tool that provides (few) of the functions that desktop GIS software offers. But it excels at making simple and somewhat complex maps.

I first used GeoCommons over a year ago. I started using it because it would convert whatever data you uploaded into another format that was probably more useful. I mentioned it in this article about converting files. For example, if you have a KML file, you can upload it and export it as a shapefile for GIS programs, or a CSV file to load into a table editor or spreadsheet application.

After creating the Chicago bike crash maps using Google Fusion Tables, I wanted to try out another map-making web application, one that provided more customization and prettier maps.

I found that web application and created a version of the bike crash maps, with several other data layers, in GeoCommons. I overlaid bike counts and bikeways so you can observe some relationships between each visual dataset. My latest map (screenshot below), created Wednesday, shows pedestrian counts in downtown Chicago overlaid with CTA and downtown Metra stations, as well as the 48 intersections with the most pedestrian collisions (from this UNC study, PDF).

Screenshot of pedestrian count map described above.

How these online GIS tools can be useful to you

I bet there’s a way you can use Google Fusion Tables and GeoCommons for your job or project. They’re extremely simple to use: they can take in data from the spreadsheets you’re already working on and turn them into themed reference maps. With mapping, you can do simple, visual analysis that doesn’t require statistical software or knowledge.

Imagine plotting your client list on a map and grouping them by age to see if perhaps your younger clients tend to live in the same neighborhoods of town, or if they’re more diverse (should you do this, keep the map private, something that you can’t do in GeoCommons – yet).

You may also find it useful if you want to create a route for your salespeople or for visiting church members at their homes. Plot all the addresses on a map, then manually filter them into different groups based on the clusters you see. With Google Fusion Tables, you can easily add a new column with the GROUP information and apply a numbered or lettered group and then re-sort.

Other things you can do in GeoCommons

  • Merge tables with geography – I uploaded two datasets: a table containing census tract IDs and demographic information for Cook County I downloaded from the American FactFinder 2; and a shapefile containing Cook County census tracts boundary information. After merging them, I could download a NEW shapefile that contained both datasets.
  • Make multi-layer maps
  • Symbolize based on frequency/rate
  • Convert data – This is by far the most useful feature. It imports “shapefiles (SHP), comma separated values (CSV), Keyhole Markup Language (KML), and GeoRSS” and exports “Shapefile, CSV, KML, GeoRSS Atom, Spatialite, and JSON” (from the GeoCommons user manual).

Read my tutorial on how I created the pedestrian map with GeoCommons.

Trying out uDig, a free, multi-platform GIS application

ArcGIS is the standard in geographic information system applications. I don’t like that it’s expensive, unwieldy to install and update, and its user interface is stymying and slow*. I also use Mac OS X most of the time and ArcGIS is not available for Mac. It doesn’t have to be the standard.

I’ve tried my hand at Cartographica and QGIS. I really like QGIS because there’re many plugins, it’s open source, there’s a diverse community supporting it, and best of all, it’s free. I’ve written about Cartographica once – I’m not a fan right now.

My project

  • The data: Bicycle crashes in the City of Chicago as reported to IDOT for 2007-2009
  • Goal: Publish an interactive map of this data using Google Fusion Tables and its instant mapping feature.
  • Visualizing it: Added streets (prepared beforehand to exclude highways), water features, and city boundary (get that here)
  • Process: Combine bike crash data; reproject to WGS84 for Google; remove extraneous information; add latitude/longitude coordinates; export as CSV; upload to Google Fusion Tables; map it!
  • View the final product

Trying out uDig

In reaching my goal I had a task that I couldn’t figure out how to complete with QGIS: I needed to combine three shapefiles with identical table schemes into one shapefile – this one shapefile would eventually be published as one map. The join feature in fTools wasn’t working so I looked for a new solution, uDig, or “User-friendly Desktop Internet GIS.”

The solution was very easy. Highlight all the records in the attribute table of one shapefile, click Edit>Copy, then select the destination table and click Edit>Paste. The new records were added within a couple seconds. I could then bring this data back into QGIS to finish the process (outlined above under Project). I did use fTools later in the process to add lat/long coordinates to my single shapefile.

After adding more data to better visualize the crashes in Chicago, I noticed that uDig renders maps to look smoother and slightly prettier than QGIS or ArcGIS. See the screenshot below.

A screenshot of the three bicycle crash datasets (2007, 2008, 2009) with the visualization data added.

The end product: three years of police reported bicycle crashes in the City of Chicago on an interactive map powered by Google Fusion Tables, another product in Google’s arsenal of GIS for the poor man. View the final product.

*I haven’t used ArcGIS version 10 yet, which I see and read has an improved user interface; it’s unclear to me and other users if the program’s been updated to take advantage of multi-core processors. ESRI has a roundabout way of describing their support.

Bike crash reporting tool: I receive a response to my FOIA request

UPDATE 12-15-10: I forgot to add that the letter stated that the Freedom of Information Act doesn’t require the responding agency to create new datasets or records where one doesn’t already exist. This means that if what you ask for doesn’t exist in their databases or file cabinets, the agency is not about to filter or search through existing data to create a custom set for you.

I continue to prepare to create a bicycle crash reporting tool (or web application). Here are the previous posts. Readers have sent me many great suggestions and concerns about how to create it, what data to use, and how to present such data. I don’t expect to begin any demonstrable work on this until mid-January when I return from my 21-day European vacation.

Today I received a response letter from the Chicago Police Department regarding my recent FOIA request for bicycle crash data.

This was disappointing: “After a thorough search, it was determined that the Department has no existing record responsive to your request.” I thought, “that doesn’t seem right. They don’t make reports on bicycle crashes?”

Police respond to a bicycle crash in Newberg, Oregon. Photo by Matt Haughey.

The letter later states, “The Department  does not currently possess a record which aggregates bicycle crash data.” Ah, this means something now. It seems that while the Chicago Police Department does make reports on bicycle crashes, it doesn’t keep a running tally or stored database query which it can use to produce the data I want – what I want would require a little more work, I guess.

The final paragraph does recommend that I contact the Illinois Department of Transportation Division of Traffic Safety’s Crash Reporting Section, where the police forward their reports. It turns out that I already received crash data on IDOT and I’m “playing around with it” using Google’s Fusion Tables.

3D experimentation to improve pedestrian environment

3D experimentation to improve pedestrian environment from Steven Vance on Vimeo.

The movies aren’t the only place where you’ll see in 3D! Go check out Clark and Deming (about 2540 N Clark Street) in the Lincoln Park neighborhood to see a special pedestrian safety marking on the pavement. They were installed on October 18, 2010.

Designed to increase nighttime visibility

Who’s involved?

  • Chicago Department of Transportation (CDOT)
  • National Highway Traffic Safety Administration (NHTSA)
  • Western Michigan University (WMU)

All three entities are involved in the installation of these optical illusion zig-zag markings.

Between and including years 2005 and 2009, there were at least 2 reports of injuries to people walking and at least 9 reports of collisions involving people riding bikes*. With that data in mind, I’m not sure why this location was selected for a pavement marking whose aim is to improve pedestrian safety. The data do indicate that this intersection has a lot of bicycle-related collisions, much more than I’m seeing for other intersections.

Clark and Deming

Curiously, there are no automobile traffic counts for miles in either direction on Clark Street so one cannot compare the number of collisions at the Clark and Deming intersection with other intersections in town. Out of over 1,200 count locations, Clark Street in Lincoln Park was skipped.

Not really stopping for pedestrians

*Data from the Illinois Department of Transportation Safety Data Mart (which was taken down in 2015 or 2016)