The landscape of the United States’ transportation system is in the midst of an evolutionary period: we are beginning to see a transition to alternatively fueled vehicles; advancements in technology are continuing to change the way the public views transportation; there is widespread recognition of the impact of transportation on human health; and we are seeing significant investments from the federal government to rebuild our nation’s infrastructure. As we continue through this transformational period, policy makers, practitioners, and members of the public all have a vested interest in ensuring that our transportation infrastructure meets the needs of the travelling public, while being environmentally and economically sustainable—and perhaps most importantly—enhancing public health. At CARTEEH, we have developed guiding principles to ensure these needs are met. We believe that transportation infrastructure must be Sustainable, Multimodal, Accessible, Resilient, and Technological, or SMART.
As part of CARTEEH’s SMART initiative, we have developed a Health Equity Framework for decision makers, practitioners, and members of the public to better understand the impact that transportation infrastructure has on human health, and the approaches to enhance health equity in our nation’s transportation system.
What is the Health Equity Framework?
The built environment—including transportation infrastructure—can present many challenges and opportunities towards improving public health. The way that our communities are designed, operated, and maintained is a key social determinant of health that can influence our exposures and the way we live. At the Center for Advancing Research in Transportation Emissions, Energy, and Health (CARTEEH)—a USDOT funded University Transportation Center—we take a holistic view of the relationship between transportation and public health. The foundation of CARTEEH’s health-equity philosophy was established through research that documented 14 Pathways Between Transportation and Health, shown below:
Why Health Equity in Transportation?
As transportation practitioners strive to plan, develop, and maintain infrastructure that minimized detrimental impacts to public health, CARTEEH’s Health Equity Framework builds on the 14 Pathways to provide transportation implementors with straightforward health equity objectives and their associated health impacts as well as a practitioner’s toolkit, which includes strategies to achieve each objective; indictors to measure the health equity of objectives; and a variety of existing tools that help practitioners further implement health equity in transportation infrastructure decision making.
While transportation systems are one component of our environment that can be designed to improve access to health-promoting destinations and increase physical activity, it can also expose the public to impacts that are harmful to public health. These impacts include air pollution, traffic violence, traffic-related noise, and other harmful exposures that can result in a wide range of health effects, such as adverse respiratory, cardiovascular, and even neurological diseases.
To better understand the effects that transportation infrastructure has on public health, the following graphic shows the number of deaths associated with traffic-related air pollution (TRAP) in the United States (note that PM2.5 is the air pollutant most closely associated with TRAP).
In addition to air pollution, traffic violence is also a significant contributor to detrimental health impacts, including serious bodily harm and death. The following graph shows the total number of deaths due to traffic crashes in the United States.
While traffic-related air pollution and traffic violence continue to detrimentally impact public health, physical activity associated with transportation can enhance public health. As shown in the graph below, deaths associated with low levels of physical activity have trended downward since 2000. However, in 2019, over 37,000 Americans died due to low levels of physical activity. While there are many factors that contribute to low physical activity levels, transportation is a significant factor, and increasing options for active transportation may decrease the number of Americans who die from low physical activity.
How do we Increase Health Equity in Transportation?
The CARTEEH Health Equity Framework developed eight objectives that focus on key contributors to health equity. While traffic-related air pollution, traffic violence, and physical activity are often cited as the primary considerations to address the impacts of transportation on public health, there are several additional considerations that practitioners can incorporate into the planning, development, and maintenance of transportation infrastructure to holistically increase health equity in transportation.