# Just how many taxi vs. bicycle crashes are there? A Google Refine story

On this Chicagoist story about how IDOT will now collect data on doorings (instead of ignoring that crash type as they preferred), I opened the story photo entitled “Cabbie takes down another” by Moe Martinez. His photo caption reads, “you see it alot … thankfully this guy seemed to be relatively ok … coherent and what not.”

I wanted to know just how often “we” see taxi drivers crashing with people riding bicycles. You can’t filter by vehicle type in either mine or Derek’s bike crash maps, but you can via the Fusion Table.

I decided to get the answer via Google Refine and make a screencast to show you just how quick and powerful a tool it is.

2. Click on the VEH1_SPECL column’s down arrow, then Facet>Text Facet.
3. In the facet box, sorted alphabetically, find “TAXI/FORE HIRE.”
4. The number of rows that apply is listed: 353.
5. Divide 353 by the total number of rows, 4931, multiply by 100, and you get your percentage.

Taxi drivers are involved in just 7.2% of bicycle crashes in Chicago in 2007-2009.

The majority of crashes, at 66%, involve people driving “PERSONAL” vehicles. And 80% of those crashes are with a passenger vehicle that’s not a van, minivan, SUV, truck, or bus (so probably a sedan or coupe). Let’s look at more data.

How many taxis are there and how many personal vehicles are there? Are taxicabs involved in a disproportionately higher number of crashes?

About 781,023 people drive to work, either alone or with someone else, in Chicago (data from 2005-2009 5-year American Community Survey). 1,063,047 households have 1,218,594+ vehicles available in Chicago. Let’s assume the 7,000 taxicabs in Chicago are not counted as a “vehicle available.”* That’s 1,225,594 “personal” vehicles. If all were on the road at the same time, only 0.57% of them would be taxicabs. But they’re not on the road at the same time. So let’s take that number of people who drive to work and add 7,000 vehicles to it. So of those 788,023 “vehicles” now on the road, just 0.88% of them are taxicabs.

So it does seem that taxicabs are involved in a disproportionate number of crashes when compared to their presence on the streets. However, taxicabs are most likely driven more more miles and for more time than personal vehicles thus making their exposure to people bicycling greater than drivers of other vehicles. (A majority of “personal” trips are very short.)

New data coming soon

I can’t wait to get the 2010 crash data. Here’s why: In 2007, students in a taxi driver training course at Harold Washington College received some education about sharing the road with bicyclists:

A pilot “Share The Road” education module was launched at the taxi training school at Harold Washington College. It includes a 25-30 minute lecture, with discussion. After the pilot, the class will be required for all people training to drive taxis in Chicago. In the future, bicycle questions will be included on the exams required to become taxi drivers. June 2007 MBAC meeting minutes (PDF).

The number of crashes between taxi drivers and people riding bikes jumped from 2007 to 2008, but declined heavily between 2008 and 2009. More data will show us a clearer trend that may lend insight into the impact of the “Share The Road” education module.

*Notes

The question (PDF) on the American Community Survey asks, “How many automobiles, vans, and trucks of one-ton capacity or less are kept at home for use by members of this household?” This may or may not include taxicabs stored at home.

I don’t know how many taxicabs there are in Chicago, but the Chicago Sun-Times reported there are approximately 7,000.

Enthusiast for urbanism, bicycling as transportation, and open data. Building a bicycle culture in Chicago.

This makes sense to me. Sure taxi drivers cut off cars constantly but that’s because they’re flowing with traffic. They know what’s possible and operate right on that line. For the most part, they’re extremely aware of their surroundings. When I’m biking it’s not the taxi’s I’m worried about.

• http://www.stevevance.net/planning Steven Vance

When I bike downtown, I do worry about taxis. And buses. Well, it’s a bunch of chaos!

I should do a geographic analysis on taxi-bike crashes. There’s a higher density of taxis being driven in the Loop. Perhaps the frequency of taxi-bike crashes is higher there.

• http://blog.theplannersdreamgonewrong.com jason tinkey

The frequency (and density) of all crashes involving pedestrians and cyclists is much higher in the Loop than anywhere else in the city, it’s a bit of an outlier. But the casualty rate, derived from the number of crashes that are coded 3 or 4 for injury severity, is actually slightly lower than the citywide average, most likely due to a combination of lower average speeds and quicker response times.

• http://www.stevevance.net/planning Steven Vance

That’s a good observation: Loop has lower average speeds, quicker response times.

Stay away from using numbered codes. The original data from IDOT is coded as A, B, C, PD, and F. I converted them to numbers for faster processing. I chose A=1, B=2, C=3, PD=4, and F=5 and it’s not the best order. A friend working on a bike crash project re-ordered the codes.

• http://blog.theplannersdreamgonewrong.com jason tinkey

Is there a difference between the two fields? I’ve always been under the impression that they were more or less interchangeable. PD=0, C=1 etc up to F=4…I never noticed any discrepancies, but then again I never really looked for them.

• Marmie

Steve, What sources do you have on crashes between bikes (unmotorized) and trains?

• http://www.stevevance.net/planning Steven Vance

I just requested this data from the Illinois Commerce Commission via FOIA for Cook County in 2007-2010. If you want different data, you should ask them for it.