A new study [PDF] commissioned by the Active Transportation Alliance put forth a "conservative" estimate that Chicagoans make nearly 125,000 bicycle trips each day for transportation, in addition to purely recreational trips. Almost 91,000, or 73 percent, of the trips are utilitarian – for shopping, errands, church, and doctor appointments.
Active Trans said in a press release that they believe this may underestimate the total number of trips. Their data shows small annual increases in commute-to-work trips, but didn't gauge how utilitarian trips may have grown since the data collection period.
The study authors from Alta Planning + Design combined local and nationally-collected trip data, notably the Chicago Metropolitan Agency for Planning’s household travel survey in 2008 and two sets of reports from the Census Bureau's American Community Survey from 2006 to 2011.
Using these surveys allowed the authors to describe other characteristics about Chicago's bicyclists. From the Census, they found that people who earn less than $24,999 each year are the most likely to commute by bike to work, while those making $100,000 to $124,999 are least likely. Oddly, though, those who make $150,000 or more are slightly more likely to make a bicycle trip.
The study estimated that "winter ridership volumes equal nearly 40 percent of average summer volumes," a conclusion made from Chicago's limited seasonal bike count data.
Women make fewer bike trips than men, especially in the winter. 48 percent of Chicagoans are male, but men "are over-represented" among bicyclists. The month with the highest share of women bicycling, according to 2012 counts at six sites, was July with 32 percent, an increase over 23 percent in February.
The study examined changes in other cities, recently replicated here in Chicago, that suggest that the city could achieve its goal of having five percent of short trips on bikes. Chicago’s expanding bikeway network could spur more bike trips: The study points out that Portland's bike counts expanded along with its growing bikeway network. Additionally, the introduction of Divvy bike-share will boost bicycling, just as it Capital Bikeshare's introduction did in Washington, D.C. However, the study didn’t estimate the effect of either of these influences, and besides, the circumstances in each case are unique.
The report mentioned a third factor that could increase ridership – marketing bicycling as a "preferred transportation option for Chicagoans" – but did not elaborate on this, or provide a parallel case study elsewhere.
The study authors did the best they could with the available survey data, but a big issue about monitoring bicycle trips remains. Unless similar surveys and studies are done regularly, or unless the city expands its meager bike count program, Chicago will never be able to monitor the growth of bicycling locally -- and thus the progress towards its five percent goal.
