Tag: IDOT

Finding data about traffic and roads in Illinois

June 16, 2012 / / 0 Comments

There are two good websites that provide information about roads, traffic, and their many attributes. One is provided by the Illinois Department of Transportation (IDOT) called Getting Around Illinois (GAI). The second is the Traffic Count Database System (TCDS).

Both provide Average Daily Traffic (ADT) counts with TCDS making the information easier to find and presents more of it.

The GAI map has an important layer: jurisdiction. With that information you can determine who has “ownership” of a road. Jurisdiction has been an important factor in the nearly year-long delay of the Jackson Boulevard protected bike lane segment from Ogden Avenue to Halsted Street. IDOT has jurisdiction over this segment (which continues east to Lake Shore Drive; the road is also known as Route 66) and is requiring that the Chicago Department of Transportation do more analysis and revise their designs.

If you are looking for ADT counts, I highly recommend TCDS as it uses the more familiar Google Maps and doesn’t require the Microsoft Silverlight plugin (which is slow and often denigrated with poor usability applications).

GAI has truck routes and crash information as well.

Stats from the OECD: Comparing traffic injuries of the United States and Netherlands

May 21, 2012 / / 0 Comments

For an article I’m writing for Architect’s Newspaper about the Chicago Forward CDOT Action Agenda, I wanted to know about traffic injuries and fatalities in the United States, but compared to the Netherlands and Denmark and other places with a Vision Zero campaign (to have 0 traffic deaths each year).

I already knew the OECD had a good statistics database and web application. With a few clicks, I can quickly get a table of traffic injuries (casualties) listing just the countries I want. I can easily select the years I want, too.

In one more click the web application will show a time animated bar chart. A feature I’d like to see added is dividing the figure (in this case traffic injuries) by the population. Check out the video to see what it looks like. The United States looks to be in terrible shape, but our country has several times more residents.

I had trouble downloading and opening the CSV file of the data table I created. The XLS file was damaged, also. The built-in Mac OS X Archive Utility app couldn’t open the .gz file, but I used The Unarchiver app successfully.

My calculations, based on data from OECD (national population and traffic fatalities), Illinois Department of Transportation (IDOT), and the American Community Survey:

Fatalities per 100,000 in 2009

  • United States: 11.02472
  • Denmark: 5.48969
  • Netherlands: 4.35561
  • Sweden: 3.84988
  • Chicago: 16.74891
  • United Kingdom: 3.83555

Chicago’s fatality rate per 100,000 citizens in 2009 was 16.75 (473 deaths on the roads). The fatality rate dropped in 2010: just 11.65 deaths per 100,000 residents (315 deaths on the roads; the population also decreased).

Updated September 28, 2012, to add the United Kingdom. 

Crashes by bike or by foot at different intersections

January 16, 2012 / / 0 Comments

While working on a private web application that I call Chicago Crash Browser, I added some code to show the share of pedestrian and pedalcyclist crashes. The site offers users (sorry I don’t have a web server that can make it public) a list of the “Top 10” intersections in terms of bike crash frequency (that’s bike+auto crash). You can click on the intersection and a list will populate showing all the pedestrian and pedalcyclist crashes there, sorted by date. At the bottom of the list is a simple sentence that tells what percentage pedestrian and pedalcyclists made up at that intersection.

I’m still developing ideas on how this information may be useful, and what it’s saying about the intersection or the people using it.

Let me tell you about a few:

Milwaukee Avenue and Ogden Avenue

I mentioned in my article Initial intersection crash analysis for Milwaukee Avenue that this intersection is the most bike crash-frequent.

23 crashes within 150 feet of the center, 2005-2010

82.61% bike crashes **

17.39% ped crashes.

Ashland Avenue and Division Street

28 crashes within 150 feet of the center, 2005-2010

46.43% bike crashes

53.57% ped crashes **

Milwaukee, North and Damen Avenues

46 crashes within 150 feet of the center, 2005-2010

39.13% bike crashes

60.87% ped crashes **

Halsted Street, Lincoln and Fullerton Avenues

38 crashes within 150 feet of the center, 2005-2010

42.11% bike crashes

57.89% ped crashes **

Montrose Avenue and Marine Drive (Lake Shore Drive ramps)

11 crashes within 150 feet of the center, 2005-2010

90.91% bike crashes **

9.09% ped crashes

Why do you think some intersections have more of one kind of crash than the other?

People walking at Milwaukee-North-Damen.

The Chicago Crash Browser can be made public if I have a host that offers the PostgreSQL database. Do you have one to offer?

Rambling about automobile crash data and cellphone distraction

October 4, 2011 / / 0 Comments

How often do bicyclists get involved with crashes because of cellphone distraction? See the table below. And how many crashes are caused by the bicyclist being distracted by a cellphone? We won’t and don’t know. 

The Chicago City Council will vote tomorrow on ordinance 02011-7146 to add a new section in Chapter 9 of the Municipal Code of Chicago: “9-52-110 Use of communication devices while operating a bicycle.”

In a Chicago Sun-Times article today, Matthew Tobias, the Chicago Police Department’s deputy chief of Area 3 patrol, reported on the number of citations that the department has issued to drivers in violation of the cellphone ban: “from 2,577 administrative violations in 2008 to 10,920 in 2009 and 19,701 last year” (known as “citations issued” in the table below).

I looked at the crash data to see how many crashes were coded as having been caused by “Distraction – operating an electronic communication device (cell phone, texting, etc)”.

Out of 274,488 recorded crashes in 2008, 2009, and 2010, there were 331 crashes which had a Cause 1 or Cause 2 of “Distraction – operating an electronic communication device (cell phone, texting, etc)”. The table below compares the rates of crashes to the rates of citations issued and the number of crashes that the police noted were caused by cellphone distraction. It also shows the number of these “cellphone distraction” crashes that involved bicyclists and pedestrians.

Year Citations issued Automobile crashes Cellphone distraction crashes % of cellphone distraction crashes Involved with bicyclists? Involved with pedestrians? National VMT (billions)*
2008 2577 111,701 91 0.081 3 10 2973.47
2009 10920 81,982 130 0.159 1 7 2979.39
2010 19701 80,805 110 0.136 6 8 2999.97

Maybe this data shows that the increased enforcement is causing fewer crashes?
However data for cyclists’ involvement in crashes and their cellphone use WON’T BE recorded unless there’s a rule change as the cause is only recorded for the vehicle involved in the crash, and bicycles are devices, not vehicles.

None involved fatalities.

*Yep, that’s 2 thousand billion. Read it like this, 2 trillion 973 billion and 470 million. VMT data from Bureau of Transportation Statistics.

Federal funding primer and why projects take so long to construct

June 15, 2011 / / 0 Comments

Many Chicagoans who ride bikes are in awe (myself included) at how fast the Kinzie Street protected bike lane (the first of its kind in the city) has been designed and constructed in four weeks.

I explain how it’s been possible to do something so fast:

  1. Federally funded projects, like “commuter bicycle parking” (u-rack manufacturing and installation, using CMAQ federal funding) in Chicago, are under the control of the Illinois Department of Transportation (IDOT), which must review and approve every design.  If it takes IDOT six months to tell the Chicago Department of Transportation (CDOT) it does NOT approve and requires revisions, it will take IDOT another six months to review and approve the revised design. I experienced this directly when I was modifying the current bike parking contract. That’s one extra year added to a project based on a cumbersome state review process. Cities and their mayors have been advocating the federal government to give federal aid directly to cities so they can work faster.
  2. All design work must be completed and approved by everyone before a contract can be advertised for competitive bidding. Federal funds generally cannot be used to pay for local city forces, like CDOT crews, to do the work.
  3. Then comes the procurement process…

[This process is nearly the same for all cities.]

While there is room for improvement in the above process, it’s may not be fair to blame the City or CDOT for taking a long time to implement a project like Stony Island (tentatively scheduled for 2014), when Chicago doesn’t have authority over it’s own roads*.

If every project were locally funded – CDOT is funding the project with budgeted but unallocated funds – and approved, we could see a lot more projects like the Kinzie Street protected bike lane happening very fast. It should be obvious, also, that Mayor Emanuel and new CDOT Commissioner Gabe Klein are extremely motivated to show their commitment to the transition plan as well as complete this project by the Bike To Work Day Rally on Friday, June 17th.

*This can be interpreted in two ways:

  1. There are roads in the city that are under the jurisdiction of the state providing an additional burden when it comes to modifying them.
  2. The process described above removes from the City authoritative control of its roads when projects modifying those roads are funded in part by the federal government.

Construction on Kinzie Street has been happening at a breakneck pace.