The black cloud looming over all analysis of non-motorized transportation (bicycling or walking) is poor
data. There exist a variety of sources from which bicycle behavior can be gleaned; for example, the
census, metropolitan/nationwide travel surveys, facility specific surveys or counts, or national surveys
such as that administered by the Bureau of Transportation Statistics (U.S. Department of Transportation
2003). Specific use and facility information may be available for select areas throughout the country. The
strengths and weaknesses of these data sources are adequately documented (U.S. Department of
Transportation 2000). A common theme is that existing behavioral bicycle data lacks the both the breadth
and quality necessary for reliable analysis. Analysis of cycling use has been especially marginalized
because of its relatively low levels of use.