UPDATE: I added data from years 2005-2007 to complement existing 2008-2009 data in Table 1 as well as a visual representation. I have also added data from the 3-year estimates to Table 2.
UPDATE 01/20/11: Added the most recent 3-year estimate that the Census Bureau released in January 2011 to Table 2.
I want to update readers on the changes between the 1-year estimate data reported in that article (from 2008) and the most recent 1-year estimate data (from 2009). Percentages represent workers in the City of Chicago aged 16 and older riding bicycles to work.
Table 1 – Bicycling to work, 16 and older, 1-year estimates
View graph of Table 1.Â MOE = margin of error, in percentage points.
We should be concerned about the possibleÂ decrease in the percentage of women riding bicycles to work, especially as the population size increased. The margin of error also decreased, thus suggesting an improvement in the accuracy of the data.Â There have already been many discussions (mine, others) as to why it is important to encourage women to ride bicycles and also what the woman cycling rate tells us about our cities and policies. If the decrease continues we must discover the causes.
But Table 1 doesn’t tell the full story.
As Matt points out in the comments below, the number of surveys returned for 1-year estimates is smaller than that from the Decennial Census. Therefore, I took a look at the two 3-year estimates available, each having a larger sample size than the 1-year estimates (see Table 2). The data below seem to show the opposite change than seen in Table 1: that the number of women bicycling to work has increased. The crux of our quandary is sample size. The sample size is the number of peopleÂ who are asked, “How did this person usually get to work LAST WEEK?”
Table 2 – Bicycling to work, 16 and older, 3-year estimates
The number of discrete females who bike to work has decreased in the most recent survey (2007-2009) while the total number of workers 16 and older has increased, giving females bicycling to work a smaller share than the previous survey (2006-2008). We must be careful to also note the margin of error for females bicycling to work is Â±499.
Matt suggested that sustainable transportation advocates “push for higher sampling” to reduce “data noise” and increase the accuracy of how this data represents actual conditions. I agree – I’d also like more data on all trips, and not just those made to go to work. Household travel surveys attempt to reveal more information about a region’s transportation.
One of the two overall goals of the Bike 2015 Plan is “to increase bicycle use, so that 5 percent of all trips less than five miles are by bicycle.” Unfortunately, the Plan doesn’t provide baseline data for this metric, but we can make some inferences (there will probably be no data for this in 2015, either). The CMAP Household Travel Survey summary from 2008 says that the mean trip distance (for all trips) for Cook County households is 4.38 miles (under five miles). The same survey says that for all trips, 1.3% were taken by bike. These can be our metrics. *See below for men/women breakdown. Note that no data for “all trips” exists for the City of Chicago.
We will not achieve the Bike 2015 Plan goal unless we do something about the conditions that promote and increase bicycling. Achieving the goals in the Bike 2015 Plan is not one group or agency’s responsibility. The Plan should be seen as a manifestation of what can and should be done for bicycling in Chicago and we all have a duty to promote its objectives.
Please leave a comment below for why you think the rate of women who bike to work has stayed flat and decreased, or what you think we can do to change this. Does it have to do with the urban environment, or are the reasons closer to home?
*The same survey also said: Cook County males used the bike for 1.9% of all trips. Cook County females used the bike for 0.8% of all trips.
Table 1 data comes from the 1-year estimates from the American Community survey, table S0801, Commuting Characteristics by Sex for the City of Chicago (permalink), which is a summary table of data in table B08006.Â Table 2 data directly from American Community Survey tableÂ B08006.
About Steven Can Plan
I started this blog in 2007 as the writing assignment for an introductory urban planning class at UIC. It's about cities (mainly Chicago), GIS oftentimes, and transportation (mainly bicycling). Learn more about me, Steven Vance. I also write for Streetsblog Chicago.
Steven Can Plan is hosted on Dreamhost.
Chicago Bike Map App
The Chicago Bike Map app is a bike and street map stored entirely in your iOS device – no data connection required. The map is designed to look much like the City of Chicago's official printed and online bike map. The app works on iPhone, iPod touch, and iPad.
Highly Recommended Bike Products
The best value taillight. It has three red LEDs that alternate and provide extreme brightness. I have two of these.
So far my longest trip was 40 miles on this saddle. It molds to your butt like Birkenstock sandals mold to your feet. The springs make the bike ride a little more comfortable and more fun (weird, because you bounce up and down on them). It also looks gorgeous. Comes in 3 colors - I got black.
Bells can be quite useful, especially to tell people in front that you're passing them. I like the ding-dong bell the best. It makes a solid DING and then DONG on the spring's return.
Traffic: Why We Drive the Way We Do (and What It Says About Us) by Tom Vanderbilt
As someone who doesn't like driving, but believes that cars can be efficient in moving groups of people and goods, this is my favorite book.
Making Maps: A Visual Guide to Map Design for GIS by John Krygier PhD, Denis Wood PhD
If you are going to make a map, whether it be hand drawn or digital, you should really give this book a read. Then read it every time you make a map. It will help make sure your maps are laid out sensibly, in a way that others can easily read, and that it doesn't include fluff or unnecessary data.
Joyride: Pedaling Toward A Healthier Planet by Mia Birk, With Joe (Metal Cowboy) Kurmaskie, Joe Kurmaskie, Jim Moore
I met Mia Birk in October 2011.
Sustainable Transportation Planning: Tools for Creating Vibrant, Healthy, and Resilient Communities (Wiley Series in Sustainable Design) by Jeffrey Tumlin
I was sent a review copy. I'm really excited to open it up and start reading because I've been disappointed with textbooks in the past that don't focus on bicycle and pedestrian planning.