Category: Tools

Are protected bike lanes going in the right places?

September 29, 2011 / / 0 Comments
Bike crash map of Ogden, Milwaukee, Chicago

Common bike-car crash locations in West Town. The bottom blue circle identifies Ogden/Milwaukee, where there is a yellow trap for northbound, left-turning motorists (from Milwaukee to Ogden) that makes them run into southbound bicyclists who have a green light.

My contribution to a discussion on The Chainlink, Are protected bike lanes going in the right places?

Kelvin, Milwaukee/Ogden/Chicago is the intersection along Milwaukee Avenue with the highest number of bicycle crashes. I created this table and map to show them, using data from 2007-2009.

The blue rings on the map are called, in GIS parlance, “buffers” and are circles used to select things (in this case, bike crashes) within a certain distance of the circle center. In this map I used 50 feet radius buffers (100 feet diameter). While this distance encompasses the intersection from center to all four curbs, it doesn’t encompass the crashes that happened just outside the buffer that were still most likely influenced by the intersection (like drivers’ turning movements).

I am working on a project with three friends to create a better map and “crash browser”. I mentioned it in the last story on Grid Chicago in this post. For this project, we are using 200 feet radius (400 feet diameter) buffers to ensure we encompass the entire intersection and the area in which it still has an effect. This also grabs the bike lane “pinch points”, places where a bike lane doesn’t start until 100-200 feet beyond the intersection.

I am also concerned with the strategy and approach CDOT is using to choose locations. It’s not transparent; at MBAC, CDOT said they were choosing locations “without controversy and that could be implemented quickly”.

Read more about Kinzie Street, Chicago’s first protected bike lane, and my other thoughts on protected bike lanes. 

How to upload shapefiles to Google Fusion Tables

September 25, 2011 / / 0 Comments

It is now possible to upload a shapefile (and its companion files SHX, PRJ, and DBF) to Google Fusion Tables (GFT).

Before we go any further, keep in mind that the application that does this will only process 100,000 rows. Additionally, GFT only gives each user 200 MB of storage (and they don’t tell you your current status, that I can see).

  1. Login to your Google account (at Gmail, or at GFT).
  2. Prepare your data. Ensure it has fewer than 100,000 rows.
  3. ZIP up your dataX.shp, dataX.shx, dataX.prj, and dataX.dbf. Use WinZip for Windows, or for Mac, right-click the selection of files and select “Compress 4 items”.
  4. Visit the Shape to Fusion website. You will have to authorize the web application to “grant access” to your GFT tables. It needs this access so that after the web application processes your data, it can insert it into GFT.
  5. If you want a Centroid Geometry column or a Simplified Geometry column added, click “Advanced Options” and check their checkboxes – see notes below for an explanation.
  6. Choose the file to upload and click Upload.
  7. Leave the window open until it says it has processed all of the rows. It will report “Processed Y rows and inserted Y rows”. You will be given a link to the GFT the web application created.

Sample Data

If you’re looking to give this a try and see results quickly, try some sample data from the City of Chicago data portal:

Notes

I had trouble many times while using Shape to Fusion in that after I chose the file to upload and clicked Upload, I had to grant access to the web application again and start over (choose the file and click Upload a second time).

Centroid Geometry – This creates a column with the geographic coordinates of the centroid in a polygon. It lists it in the original projection system. So if your projection is in feet, the value will be in feet. This is a function that can easily be performed in free and open source QGIS, where you can also reproject files to get latitude and longitude values (in WGS84 project, EPSG 4326). The centroid value is surrounded in the field by KML syntax “<Point><coordinates>X,Y</coordinates></Point>”.

Simplified Geometry – A geometry column is automatically created by the web application (or GFT, I’m not sure). This function will create a simpler version of that geometry, with fewer lines and vertices. It also creates columns to list the vertices count for the simple and regular geometry columns.

Using Google Fusion Tables to create individual Chicago Ward maps

September 13, 2011 / / 0 Comments

I wanted to create a map of the 35th Ward boundaries using Google My Maps for a story on Grid Chicago. I planned to create this by taking the Chicago Wards boundary shapefile and exporting just the 35th Ward using QGIS into a KML file. I ran into many problems and ended up using Google Fusion Tables as the final solution.

The problems

First, QGIS creates invalid KML files. Google Earth will tell you this. I opened the KML file in a text editor and removed the offending parts (Google Earth mildly tells you what these are; you can use this validator to get more information).

Second, Google My Maps would not import the KML file. I tried a different browser and a different KML file; a friend ran into the same issue. I reported this problem to Google.

The solution

I uploaded to Google Fusion Tables a KML file containing all wards. I did this instead of uploading the single Ward because, like a database, I can filter values in the column, selecting only the row I want with “ward=35”.

After applying the filter, the map will show the boundary for just that ward. I grab the HTML code for an embeddable map and voila, the article now displays an interactive map of the 35th Ward.

Whenever I want to create a map for a different ward, I go back to this Fusion Table, make a new filter and copy the new HTML code.

A screenshot of the embedded map, showing just 1 of 50 wards, in the Grid Chicago article. 

Elsewhere

I had the same problems with QGIS exporting and uploading the KML files to My Maps the other day when I was creating maps for the abandoned railroads for Monday’s Grid Chicago article. Not thinking about Fusion Tables, I drew on the map with my mouse the lines.

Screenshot of the map of abandoned railroads. 

My first iPhone app – Request a bike rack

June 16, 2011 / / 0 Comments

Here’s a video preview of my first iOS app that will hopefully, in the end, allow you to request a bike rack in Chicago based on where you and your device are currently standing.

I don’t know if it will ever hit the Apple App Store because Apple requires developers to pay a $99 fee each year. I’m surely not going to pay this. It will be able to run on jailbroken iOS devices and it will work on iPhone, iPad, and iPod touch.

The code is based on my Bike Crash Portal website that asks permission to use your location (given automatically through HTML5 and the computer’s own location software). A fork of this project may include a mobile-optimized website that allows you to request a bike rack; again, based on your current location.

The purpose of this is to eliminate the need to know the address of where you want to request a bike rack. Oftentimes a person will arrive at their destination and not find any bike racks. Open the app, hit “Share my location” when the app loads and then tap submit. The Chicago Bicycle Parking Program (hopefully) will receive your request.

Living in a smart city

May 17, 2011 / / 0 Comments

What does living in a smart city look like?

It might look like this.

When a city can gather data on every aspect of it’s citizens activities, what should we do with it? What products, services and environments should we develop?

Many private and public sector organisations are rushing us towards a future state where every cup of coffee, cell phone, taxi, bus, street and building will be self-aware and communicating with us and each other. Rather than asking when is this future coming, I’d like to ask what will we do once it’s here.

That’s the description of a class taught by George Aye at the School of the Art Institute of Chicago. I visited the class twice to hear and watch their presentation on minimizing disruptions caused by traffic crashes at a specific intersection, but whose new system elements can be transferred to other intersections in the city. When I came back the second time, the students had figured out a way to animate the intersection using a projector and mirror (which you see at the end of the video).

A static shot of the animation on the 3D paperboard and mixed material model.

The intersection in question is “The Crotch”, or the center of Wicker Park, at Milwaukee-North-Damen. The goal was to imagine how smart processes, policies, and technologies can be used to minimize the disruption of crashes at this intersection and others like it. The first phase of the students’ plan is about preventing crashes and the second phase is about speeding up the investigation. If you want to know more, you’ll have to read the class blog, which documents, through narrative, photos and video, the students’ progress.

Some of their proposal for Milwaukee Avenue in this area included:

  • Barring private automobiles at certain times to give more room to more efficient modes, like buses and bicycles
  • During the ban period, allow taxis and possibly car-sharing cars
  • At all times of the day, deliveries (like beer) would be scheduled in advanced to better use existing and consolidated loading zones; when trucks use loading zones, they aren’t blocking traffic
  • Implement a Barnes dance (pedestrian scramble) at The Crotch to accommodate existing pedestrian crossing behaviors and speed up crossing times of what are now two-leg crossings (like walking north or south on west side of Damen Avenue, which requires a crossing distance of about 180 feet on two segments while the crosswalk signal cycle may not let you do consecutively; a direct crossing is only 72 feet)

View the full Living in a smart city photoset