May 15, 2008 - Professor Jennifer Dill's congressional briefing

On May 15, 2008, Professor Jennifer Dill participated in a congressional briefing in Washington DC sponsored by the Congressional Bike Caucus and the Active Living Research program of the Robert Wood Johnson Foundation on Biking Your Way to a Healthier Community. Her statement appears below. The Congressional Bike Caucus is chaired by Congressman Earl Blumenauer (OR) and Congressman Tom Petri (WI).

Statement of Jennifer Dill, Ph.D., Congressional Bike Caucus, May 15, 2008

Bicycling for everyday travel can be viable option in large cities.  In the past, most examples of high rates of bicycling in the U.S. were small, college towns. That's now changing. Earlier this month, the League of American Bicyclists awarded the City of Portland, OR its highest honor as a Platinum-level Bicycle Friendly Community. Portland is only the second to achieve that status; Davis, CA was the first. According to the latest Census data, over four percent of Portland's workers regularly commute by bicycle – the highest rate among all U.S. cities of over 250,000 people. The high rate of bicycle commuting in the City is linked to deliberate efforts. In 1990, only about one percent of workers in the City commuted by bike. In the period from 1991 to 2007, the City's bikeway network grew about 250%, and the number of bicyclists crossing bridges into downtown increased over 400%. At the same time, the number of reported crashes has been relatively constant, indicating a reduction in the rate of crashes.

Achieving high rates of bicycling for transportation requires a broad range of infrastructure. Bike lanes, the common focus of many cities' efforts, are just one part of what's necessary to significantly increase bicycling as a transportation mode. Other facility types, including off-street paths and bicycle boulevards, provide an environment that may be particularly important in attracting new cyclists. Bicycle boulevards are neighborhood streets with traffic calming features that discourage and slow down motor vehicle traffic, special traffic signals that help cyclists cross busy streets, and signage. The City of Portland's 30 miles of bike boulevards travel through older neighborhoods with grid street patterns, parallel to busy streets, providing cyclists with a direct route to downtown and other destinations.

Our research equipped over 160 bicyclists with GPS units, recording over 1,500 bike trips throughout the region. Preliminary analysis shows that half of their bicycle riding happened on roads with bike lanes, off-street paths, or bicycle boulevards. These facilities only represent about 15% of the infrastructure available to cyclists in the City.  Perhaps most significantly, about one out of every ten miles biked was on a bike boulevard, while these streets make up one percent or less of the infrastructure. Similarly, one out of seven miles biked was on an off-street path; these facilities make up about two percent of the infrastructure available to cyclists.

Reducing exposure to motor vehicle traffic is important to increasing cycling rates.  For the cyclists in our study, avoiding streets with lots of vehicle traffic and reducing travel distances were the most important factors in choosing their routes. In our random phone survey of adults in the region, "too much traffic" was the most often cited environmental barrier for not bicycling more. Women and people who bicycled less often were more likely to cite this as a factor. This may explain why the women in our study rode more of their miles on bike paths, bike boulevards, and low-volume neighborhood streets and fewer of their miles on roads with bike lanes, compared to men. Similarly, people who don't ride as often cycled a significantly smaller share of their miles on roads with bike lanes, and more on bike paths and neighborhood streets, compared to regular, everyday cyclists.

It's not just about lanes, paths, and bike boulevards.  Our research found that the highest rates of bicycling for transportation are in neighborhoods close to downtown with a well-connected street grid, after controlling for demographics and attitudes. Street connectivity standards and good land use planning can help create such environments. Education and encouragement are also important. The City of Portland's neighborhood-based, individualized marketing programs have helped boost cycling rates. Other infrastructure improvements in the City include bike traffic signals, colored bike lanes at conflict points, advanced stop lines (also known as "bike boxes"), signage, and roadway markings.

Policy Implications and Research Needs

• The National Bicycling and Walking Study (US DOT, 1994) set forth a federal goal to double the share of trips made by bike and on foot. Portland's experience shows that such goals are not out of reach for large cities. A commitment to this federal goal, through funding priorities, policy, and research, could help improve public health.


• Federal funding should support a variety of bicycle infrastructure, including bicycle boulevards on neighborhood streets.


• Federal policy should foster and not hinder innovation in providing new types of bicycle infrastructure, such as the boulevards and special lane and intersection markings being used in Portland, and cycletracks used extensively in Europe. Federal policy could also encourage the adoption of local street connectivity standards, which reduce biking and walking distances and make bike boulevards possible. This could be accomplished through funding of projects and the studies needed to determine their costs and benefits, along with changing he process for approving such innovation.


• The federal government could take a leadership role in collecting data on bicycle use and safety. To my knowledge, no other study in the US has collected as much detailed information on bicycle use as the one I've discussed today. And, we've only touched the surface of learning more about bicycling and its potential.

Jennifer Dill, Ph.D. is an Associate Professor in the Nohad A. Toulan School of Urban Studies and Planning and Director of the Center for Transportation Studies at Portland State University. The research described here was funded by the Active Living Research program of the Robert Wood Johnson Foundation and the Oregon Transportation Research and Education Consortirum (OTREC).