CUUATS aims to increase understanding about the different ways physiological, social, and environmental health is connected to the transportation system by including public health data in the long range transportation planning process.
Scientific evidence in public health literature has firmly established the relationship between transportation mode choice and public health, separate from the risk of injury or death as a result of a crash. In a 2010 report titled The Hidden Health Costs of Transportation, prepared for the American Public Health Association by Urban Design 4 Health, Inc., the authors cite several studies demonstrating differences between car-based communities and communities that facilitate more active modes of transportation through better support and infrastructure for walking, biking, and public transit. Residents in communities with more options for active transportation show significant physiological, social, and environmental improvements over residents in car-based communities. By choosing more active forms of transportation, such as walking, biking, or taking the bus, individuals can increase their amount of physical activity and reduce their risk of obesity. Active transportation systems combined with fewer cars on the road can also lead to environmental improvements such as lower rates of air pollution, which can contribute to pulmonary diseases and trigger asthma attacks. The figure below demonstrates this correlation on a global scale, with the US recording the highest rate of obesity as well as the lowest rates of walking, biking, and transit compared with 13 other countries.
Mode Split and Obesity Rates of Various Countries, 2008
Obesity and diabetes are two health conditions that closely tie to low levels of physical activity. Within the United States, rates of both health conditions have risen significantly since 1994, as shown in the figures below. In 2015, about 93.3 million U.S. adults (39.8 percent) were obese . The prevalence of high rates of obesity is not only a major health concern but also increases the risk of other health problems including type 2 diabetes and high blood pressure. An estimated 30.3 million people of all ages (9.4 percent of the U.S. population) had diabetes in 2015 and type 2 diabetes accounts for 90 percent to 95 percent of all diabetes cases . About 75 million adults (32 percent) have high blood pressure in the U.S., making it one of the primary or contributing causes of death . Another leading cause of death related to the transportation system has to do with vehicle emissions. Chronic Obstructive Pulmonary Diseases (COPD) is a group of diseases, including chronic bronchitis and emphysema, which has been linked to exposure to vehicle emissions including, but not limited to, particulate matter, volatile organic compounds, and nitrogen oxides. The percent of adults in the U.S. with diagnosed chronic bronchitis in 2017 was 3.5 percent and emphysema was 1.4 percent.
United States Prevalence of Obesity and Diabetes by State, 1994-2015
Local health data is incorporated into transportation planning processes, when possible, to better understand the different ways local health is impacted by the transportation system in the MPA. The Champaign-Urbana MPA, like most communities in the United States, is considered auto-centric, which means most people rely on automobiles for getting around, although it is important to note that local rates of active transportation are higher than the national average. As referenced in the transportation section, the majority of workers 16 years and older in the MPA drove alone to work in 2017, which does not include additional time spent driving alone to places other than work like school, the supermarket, restaurants, etc. Despite the MPA having higher rates of active transportation than the national average, the most recent data shows that local rates of obesity and diabetes have risen in Champaign County (from 26.2 percent to 31.1 percent and 8.3 to 9.9 percent respectively) from 2005 to 2016, similar to national trends. The chart below shows increases in the prevalence of obesity and diabetes in Champaign County from 2005-2016. Diabetes/obesity continues to be identified as one of the top four health concerns in the Champaign County community, first in the 2014-2016 and again in the 2018-2020 Community Health Improvement Plan, coordinated by the Champaign-Urbana Public Health District (CUPHD) .
Rates of Diabetes and Obesity in Champaign County, 2005-2016
What changes could be made in the local transportation system that could positively impact the health of its users? To combat obesity, the U.S. Department of Health and Human Services recommends that adults age 18-64 get at least 150 minutes of physical activity a week. For kids the recommendation is even higher: kids ages 6-17 should get at least 60 minutes of physical activity every day to grow and maintain a healthy body. Increasing local rates of active transportation would go a long way to increasing physical activity. To do this, not only does active transportation infrastructure need to be in place, but homes need to be located near schools, places of employment, and other destinations to make active modes of transportation realistic and desirable. Education and outreach regarding active transportation and physical activity help encourage these healthy behaviors. Programs such as the local Champaign-Urbana Safe Routes to School Project works with children and families to establish safe ways to walk and bike to schools to increase physical activity and instill positive active transportation habits at a young age.
CUUATS is currently in the process of updating a local Health Impact Assessment (HIA) created in 2014. The local HIA is intended for use as a policy analysis tool that can be used to formalize public health considerations in planning processes. The HIA was originally designed to identify relationships between the built environment and local occurrences of obesity. The analysis revealed that there were significant correlations between obesity and built environment variables such as density, service accessibility, transit connectivity, active transportation infrastructure, and more. Obesity rates were generally lower in neighborhoods that had higher population density, better land use mix, higher accessibility to jobs and services, and better transit connectivity. The following map is the 2014 HIA’s summary health index map based on health data from 2008-2012, where the higher scores represent locations with more built environment features that are correlated with higher physical activity and lower obesity. A full explanation of the results and methodologies of the 2014 HIA can be found in the HIA report, the content of which is also included in the LRTP 2040, Appendix B
For the HIA update currently underway, CUUATS staff hope to expand the assessment to include local occurrences of type 2 diabetes, hypertension, and/or chronic pulmonary disease along with obesity. Although the HIA update is ongoing and no results are currently available, the following maps show the frequency of persons diagnosed with obesity, type 2 diabetes, hypertension, and chronic pulmonary disease in each traffic analysis zone within the MPA based on a dataset from one local health provider obtained for 2015. These maps do not reflect any data from the McKinley Health Center which serves the students at the University of Illinois. This lack of data is why it appears that there is very a low prevalence of illness in an around the University district in all four maps, despite the high population density in that area.
An important limitation related to studying the relationships between different health conditions and the transportation system is that correlations do not necessarily prove causation. Many illnesses and health conditions reveal themselves in different ways in different people and result from intersections of multiple factors and risk modifiers. Investigations of local health and transportation factors should not be interpreted as asserting that the transportation system is the only factor that determines health outcomes in the community. At the same time, scientific evidence asserts that even small increases in active transportation could lead to significant decreases in chronic disease and increases in overall public health, which makes this a unique opportunity for the local transportation system to facilitate positive change in the health of the community.