Bicycling beats the odds — National bike commuter rate holds steady

Despite predictions that the number of Americans biking to work would fall after gas prices returned to ‘normal’  in 2009, the percentage has held steady at 0.55 percent. The Bicycle Friendly Communities (BFC) among the 70 largest cities also held steady with a 1 percent increase, while non-BFCs increased their commuter share by 26 percent. BFC cities still have on average about twice the percentage of commuters as non-BFC cities.

Check out the bike commuter rates for the 70 largest US Cities for 2009 (PDF). Or see the online spreadsheet (new).

And see the bike commuter rates from 2000 to 2009.

NEW! See the commuter rates for Biking, Walking, Public Transportation, and Driving alone for 2000 to 2009.

The numbers on these tables are estimates produced by the US Census Bureau based on samples of the population. There can be a large margin of error, especially for the smaller cities. See below for a discussion of the limitations of the ACS methodology.

About the American Community Survey and its limitations

The Census Bureau has released American Community Survey data for over 6,600 geographic areas that meet the 65,000 population threshold. Population sizes are based on July 1, 2009 population estimates from the Census Bureau’s Population Estimates Program, for most legal geographic areas.

The American Community Survey is the country’s largest household survey with an annual sample size of about 3 million addresses. The survey uses questionnaires and interviews to gather information on demographic, economic, and housing characteristics, including journey to work information. Annual estimates are available for geographic areas with populations of 65,000 or more, although because of limited sample sizes, bike commuting estimates are not available for all of those locations. The ACS replaces the Census Long Form questionnaire, which was given to one in six Census-takers every ten years.

Using the decennial Census and the annual American Community Surveys, the U.S. Census bureau has asked the same question about means of travel to work over time, making it is one of the best sources for tracking trends in bicycling to work levels. However, there are several limitations to using the ACS as a measure of bicycling levels. Bicycling’s share of all trips is nearly three time large than bicycling’s share of commuter travel — the 2000 Census estimated that 0.34 percent of American workers usually bike to work, in contrast, the 2001 National Household Transportation Survey (NHTS) estimated that 0.9 percent of all trips were made by bicycle — therefore, the ACS bicycle commuter percentage should not be interpreted as equivalent to the proportion of all trips.

In addition, the ACS and the decennial Census undercount bicycle commuting levels. They ask for the principal mode of travel the worker usually used to get from home to work during the previous week.

Workers were asked to list only the means of transportation they used on the largest number of days in that week. This means that if the respondent rode a bicycle to work two days but drove three, they would not be counted as a cyclist. Likewise, workers were asked only for the means of transportation used for the longest distance during the trips. If someone biked one mile to a bus stop and rode the bus for two miles they would not be recorded as a bicyclist.

Finally, it is important to note that the results of the ACS (and the Census long form) are only estimates based on population samples. The ACS releases an estimate of the number of workers 16 years old and over and the estimated number of workers who used each mode (drive alone, car-pool, public transportation, walk, bike, taxi, or motorcycle). The estimates are used to calculate the share of workers using each mode. Along with these estimates, the ACS publishes the margin of error, a range within which they can be 90 percent confident that the true number falls. For example, the in 2008 ACS estimated with 90 percent confidence that the number of bicycle commuters in New York City was between 21,162 and 27,694. The given estimate is 24,428 with a +/- range of 3,266. For communities with low counts of bicycle commuters this range can be quite large, in few cases the +/- range can be as large as the estimated number of bike commuters. Plano, Texas, for example, has an estimate of 230 and a +/- range of 235, meaning the ACS estimates with 90 percent confidence that the actual number of bike commuters is between zero (since negative five is impossible) and 465. For simplicity’s sake, these tables use the mid-point in the range, but when reading the tables, keep in mind that all percentages are in fact just estimates, some with large margins of error.

Notes:

• As stated above, the ACS numbers are estimates – differences among years or cities may not be statistically significant.
• These numbers are based on the “principal city,” not the larger Metropolitan Statistical Area (MSA).
• Population numbers in the tables have been updated to reflect the Census Bureau population estimates.