When you start your bike ride to work you may notice others in your neighborhood doing the same thing. You may even remember your citywide bike to work rate or that rates in DC and Arlington are trending up. But at the neighborhood level, bike to work rates vary significantly.

Mapping the Data

I used the 2013 American Community Survey (ACS) commuting map to create my own neighborhood level map in Google Earth. I selected the bicycle measure and then selected census tract which provides a neighborhood level view. Census tracts are small, relatively permanent statistical subdivisions of a municipality and their boundaries are updated prior to each census.

When the Census Bureau collects survey data, each household’s information is tagged to their census tract. Dividing the number of bike commuters by the number of workers (typically about two thirds of the population) equals the bike to work rate in percentage form.

A few things to note about the data:

• The bike to work data is at least 5 years old.
• The bike to work metric only captures commutes and ignores the many other trips people take on their bikes. The metric appears to undercount people who bike, because it counts people who bike to transit as transit commuters.
• The boundaries of the census tracts are drawn by municipalities or the Census Bureau and are relatively artificial.

Street Grids and Bike Lanes Matter

Arlington has a lot of neighborhood street grids and in many of those census tracts, bike to work rates are several times higher than the County rate of 1.3% (2013 ACS Survey). But in other census tracts, rates are well below that average.

South Arlington

One of the more interesting tracts contains the Aurora Hills neighborhood. It has a grid of low stress streets which connect to nearby jobs in Crystal City and the Mount Vernon Trail, which is a major bike commuter route. Back in 2013 when the census data was collected, the South Eads and South Hayes Street protected bike lanes had not even opened and even today, Aurora Hills lacks fancy bicycle infrastructure in its core. This suggests that low stress street grids are important to encourage bike commuting.

In Rosslyn, neighborhoods north of Wilson Blvd. along the Custis Trail generally have much higher rates than south of Wilson Blvd. This may be a result of that grid being a more stressful place to bike and/or lack of low stress connections to nearby trails. Distance to nearby job centers also appears to be a factor.

Alexandria

In the city of Alexandria, higher rates occur in relatively low-stress street grids of Old Town and Del Ray. But census tract with the highest percentage, part of the North Ridge neighborhood, surrounds the Old Dominion Blvd bike lanes (installed sometime between 2007 and 2009). My own tract in the Rosemont neighborhood has 2.2% or double the city wide rate of 1.1%.

Washington, DC

In Washington, DC, the largest disparity has economic and racial overtones, as the wealthier white neighborhoods generally have more bike commuters than less wealthy black neighborhoods south and east of the Anacostia River. Historically, these neighborhoods have had fewer bike lanes, trails, and low stress connections over major barriers such as Anacostia Freeway, railroad tracks, and the Anacostia River itself. However, this is not always the case as the census tracts around Howard University have high rates of bike commuting. Census tract 33.01, in which blacks outnumber whites 2:1, has the highest rate in the District of 18.6%.

Despite some caveats, these maps are a neat way to present bike commuter rates at the neighborhood level. How does your own neighborhood compare?