United States bicycle commuting rates are low compared to similarly developed countries like the Netherlands and Denmark. However, bicycle commuting shows promise for positive health outcomes, especially those related to chronic diseases like obesity, diabetes, and heart disease. Little research has been conducted in the U.S. to study the association between bicycle commuting and heart disease. Furthermore, U.S. cities need guidance on how to increase bicycle commuting rates.
The purpose of this study was to evaluate the association between U.S. bicycle commuting rates and heart disease prevalence and to identify infrastructure and policy factors most significantly associated with bicycle commuting rates in large U.S. cities. This research quantitatively defined infrastructure and policy factors and analyzed ecologic associations across the 50 most populous U.S. cities.
The results of this study are based on an ecologic analysis that evaluated associations at the census tract and city levels. Secondary data from nine sources as used to conduct the analysis. Data sources include the League of American Bicyclists Benchmarking Report, PeopleForBikes bicycle network analysis, the Centers for Disease Control and Prevention Behavioral Risk Factor Surveillance System, the U.S. Census Bureau American Community Survey, and more. A principal components analysis was conducted to identify relevant infrastructure factors for research question one; ordinary least squares regression models were derived to compare associations between infrastructure and policy factors for research question two, and latent class cluster analysis was conducted to calculate the prevalence odds ratios of the association between bicycle commuting rate and heart disease for research question three.
Three factors accounted for 70% of the variation in bicycle commuting rates. Those three factors include the average number of cyclist fatalities, the number of city employees working on bicycle projects, and bicycle network connections to public transit. The results also show that the association between bicycle commuting rate and heart disease prevalence was only statistically significant in census tract populations with predominantly high socioeconomic status, low health risk factors, and white race. The ecologic study design likely masked any positive health outcomes in populations with low socioeconomic status. The findings of this study provide valuable insights for transportation and public health practitioners, and the conclusions set the stage for future research on cycling and chronic disease outcomes in the United States. / Doctor of Philosophy / In the U.S., about 1% of the population bicycle commutes to work. Bicycle commuting is uncommon in the U.S. because many people feel it is not a safe or practical form of transportation. However, several U.S. organizations are working to make roadways safer for cyclists. Some of these organizations include The League of American Bicyclists (LAB), PeopleForBikes (PFB), and Smart Growth America (SGA). The LAB has awarded nearly 500 towns and cities with a bicycle-friendly community award, while PFB has created tools to help urban planners examine bicycle networks in their communities. SGA also helps create bicycle-friendly cities by working with elected officials to advocate for policies that will make roadways safer for cyclists. LAB, PFB, and SGA all collect data as part of their work to learn what U.S. communities are doing to support cycling.
I used LAB, PFB, and SGA data to determine the most important factors for bicycle-friendliness in the 50 largest U.S. cities. I evaluated the impact of 14 factors, including, but not limited to, protected bike lanes, network connectedness, and bicycle-friendly policy. I found that three factors had the strongest association with bicycle commuting rates in large U.S. cities: network connections to public transit, the number of city employees working on bicycle projects, and the number of deaths from cyclist fatalities. Cities looking to increase bicycle commuting should use these results to focus their efforts on improving public transit networks, increasing the number of work hours spent on bicycle projects, and identifying strategies to reduce cyclist fatalities.
U.S. cities should work towards improving bicycle-friendliness because of the population health benefits. In the past 20 years, the percentage of Americans with obesity has increased by 40%, and the percentage of Americans with Type 2 diabetes has doubled. Multiple factors contribute to obesity and diabetes, including bicycle commuting, which has been associated with decreases in both obesity and diabetes. Bicycle commuting may also be associated with heart disease, which is the leading cause of death in the U.S., but more research is needed. In the second part of this study, I evaluated the relationship between bicycle commuting rate and the percentage of Americans living with heart disease.
I used data from the Centers for Disease Control and Prevention (CDC) and the U.S. Census Bureau to understand the association between bicycle commuting and heart disease in 50 U.S. cities. I analyzed the data by census tract to understand health outcomes at a population level. I found that the association between bicycle commuting and heart disease was only significant in census tracts that were predominately high-income. I also found that bicycle commuting rates in high-income populations were three times greater than in low-income populations. In other words, health benefits were not visible in low-income populations because of low bicycle commuting rates. Low-income populations have higher rates of obesity and diabetes and would benefit the most from bicycle commuting, yet these populations confront several barriers to cycling. Cities interested in improving bicycle-friendliness should work to engage low-income populations in their work.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/106697 |
| Date | 19 November 2021 |
| Creators | Todoroff, Emma Coleman |
| Contributors | Civil and Environmental Engineering, Shealy, Earl Wade, Paige, Frederick, Coughenour, Courtney, Baker, Charlotte |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf |
| Rights | Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International, http://creativecommons.org/licenses/by-nc-nd/4.0/ |
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