National Household Travel Survey

[flickr]photo:8357047668[/flickr]

Showing undesirable pedestrian and sidewalk conditions under the Kennedy Expressway on Belmont Avenue at Kedzie Avenue. There is a bus stop here, on a portion of the sidewalk that narrows to about 2 feet. It wasn’t until I wrote this post that I realized that there is no bus route on Kedzie Avenue making this bus stop’s location quite ridiculous. There are bus stops in both directions on Belmont Avenue that are actually near businesses and residences. Explore on Google Street View.

I shop for groceries mostly at Aldi. The one nearest my house is 3,725 feet by walking (about 0.71 miles), the Avondale Aldi. The next closest store is 11,102 feet away (about 2.1 miles), the Lincoln Square Aldi, and the third closest is 11,599 feet away (about 2.2 miles), the Wicker Park Aldi. I live at Belmont and California, in Avondale.

I shop at the third closest one the most often. The Wicker Park Aldi is at Milwaukee Avenue and Leavitt Street. The reasons I shop here instead of the other two, considering that it’s two-thirds closer to home, are based on two travel factors: trip chaining (the practice of attaching multiple trips into the same one so one leaves the house less often), and trip quality (the characteristics that make the trip interesting, not interesting, safe, and unsafe). A trip, as counted by transportation planners like myself, is movement from one address to another.

For example, the Chicago Transit Authority counts trips taken on its buses and trains as “boardings”, each time a passenger pays for the bus or passes an ‘L’ station turnstile. When people change routes on the same platform or station, this additional trip isn’t counted because there’s no mechanism to do so. A person who takes a bus to an ‘L’ station is counted twice in CTA’s reports (note 1).

Continue reading How far does your expressway avoidance take you?

[flickr]photo:7532335050[/flickr]

This is another data-intensive post. For the tl;dr version, read only the introduction and conclusion sections. Photo by Mike Travis.

Jeremy Gaines asked on the Chicaogist reblog of our Monday article (about Chicago cyclists crashing less often than those in the suburbs):

[Since we only have data about how often people bike for work purposes and crash data accounts for people who are biking for any purpose,] wouldn’t the large majority of total miles traveled be racked up those who commute regularly on bikes?

That’s a good question and I don’t know if there’s enough existing data to answer it. It came after the Chicagoist article and discussion board made it seem like bike commuters had a greater than 10% likelihood of being in a crash, and a 1% likelihood of dying or receiving an incapacitating injury (with chances greater in the suburbs). I replied that one could not make these assumptions based on the data available.

Gaines is a student at Northwestern University in Evanston. He doesn’t bike because he lives so close to everything he needs; when I inquired about his motivation to leave the comment, he replied: “I suppose a headline about bike safety caught my eye, even if it doesn’t apply to me. Plus biking, being green and efficient urban space usage, means that I support it, even if I don’t do it.”

The reason this question is important is because in my original article, I calculated the number of crashes per bicyclist (the crash rate) based on two different data sets, and the likelihood of being in a crash is most likely not 10%:

The crash data set doesn’t care about the crashed bicyclist’s trip purpose
The ridership data set cares only about trips to work

Let’s see if there’s more data we can work with to gauge bicyclist safety in the city.

Continue reading Follow up: Do 10% of bike commuters really crash each year?