2 Transportation Equity and Justice. The Effects of Driving in the Built Environment: Pollution and Global Warming

Chapter overview

This chapter is divided into two sections.

• Section 1 critically examines the social and environmental implications of the relationship between the built environment and car dependency. It highlights how transportation policies and projects in U.S. cities have led to environmental injustices, introducing the concept of transportation justice and equity in planning.
• Section 2 explores the opportunities offered by the U. S. National Blueprint for Transportation Decarbonization

The Environmental and Equity Implications of Driving for CITIES

Equity in Transportation

Our understanding of justice issues in transportation, where low-income and racial minorities are marginalized in terms of access to transportation benefits, has roots in the Civil Rights Movement, which emerged in the 1950s in the U. S. (Coolsaet et al., 2020). However, the earliest form of transportation inequity in the U. S. can be traced back to the 18th century, when enslaved people who had escaped to freedom were legislated to be brought back to their owners, which is equivalent to restricted travel. Although the Civil Rights Act of 1875, 18 Stat. 335 (1875) required equal accommodation for blacks and whites in public facilities, it was voided by supreme court and later in 1878, the supreme court banned states from prohibiting segregation on public transportation. Between 1865 and 1967, more than four hundred state laws, ordinances, and amendments were passed to constitutionalize segregation. During this time, several racial conflicts, directly or indirectly, related to transportation injustice, such as the Montgomery Bus Boycott, the Freedom Rides (Arsenault, 2006), or the takeover of lands from Native Americans to enable railroad owners to expand rail transportation (Brenman, 2007).

Another practice of injustice occurred through the Federal Aid Highway Act of 1956 and the intentional routing of the interstate highway system through Black and brown communities, dividing and destroying once vibrant communities, as well as the subsequent migration of wealthier Whites (“white flight,” 2024) to the suburban ring or exurban periphery.  Despite the emergence of the Civil Rights Acts of 1964, which aimed to end segregation and discrimination based on race, color, religion, sex, or national origin, planning practices such as the aforementioned interstate highway system as well as redlining, mortgage discrimination, and racially restrictive covenants gave rise to polarized urban form, where access to opportunities are disproportionately distributed between different populations groups. Urban decentralization and suburbanization were detrimental to disinvested neighborhoods and minoritized groups and contributed to environmental racism.

Challenges with transportation inequities in the United States continue today as low-income communities and minorities receive fewer benefits and take on more potential harms from transportation projects (Bullard & Johnson, 1997). For instance, the highway system in the United States has heavily impacted low-income communities of color over the past sixty years (Weingroff, 1966). Highways were planned and constructed to connect suburbs to central cities. Historically, due to suburbanization, many employment centers have relocated to suburbs. At the same time, many vulnerable communities live near highways and congested roads, exacerbating their exposure to air pollution (Sanchez et al., 2004), or experiencing disconnection to their matched job types. This spatial mismatch hypothesis posits that greater distance to work centers, lower car ownership, and reliance on public transportation for workers dependent on low-level entry jobs (which have mostly relocated to the suburbs) all serve to amplify the economic issues for lower-income inner-city residents  (Ihlanfeldt & Sjoquist, 1998; “Spatial mismatch,” 2024).

Equity in transportation is relevant because transportation is the second-highest expenditure for American families. Lower-income families in the U. S. spend around 30% of their budget on transportation, whereas the share carried by middle-income families is about 16% (ITDP, 2024). This disparity imposes additional inequities in urban living for low-income families. Many studies reveal that income, residential location, race, and ethnicity determine access to mobility resources, especially private vehicles. Therefore, access to transportation is a crucial concern in transportation mobility and economic mobility (Chetty et al., 2019). For instance, those lacking private cars depend heavily on public transit and non-motorized transportation. The time spent commuting is greater, and the distances traveled are longer than those who drive cars (Miller, 2018). Thus, transportation equity is a complex issue that requires coordinated efforts from local, state, and national governments to improve the distribution of benefits of transportation projects among all residents.

Moreover, beyond access, other factors affect low-income communities.  Often, there is a lack of safe infrastructure for walking and biking, and these communities are exposed to higher levels of pollution associated with transportation projects, such as transit and roads.  Finally, meaningful involvement of low-income communities is essential for improving transportation justice (Burgos-Rodríguez, et al., 2023).

Previous research in travel behavior and built environment shows that the type of urban form (compact cities or sprawling) has a higher impact on commuter travel behavior (transportation mode choice) than income (Leck, 2006). This fact sheds light on the importance of the design and density of the urban form. Compact and walkable urban environments enable alternative modes of transportation, providing various modal choices and opportunities for low-income commuters. However, in the U.S., the urban form has a lesser effect on commuter behavior than in other global cities.  This is partly because of low-density and suburban developments. For instance, low-income families spend approximately 30% of their income on car-related expenses in the largest U.S. cities, while their counterparts in Mexico spend only around 3% (Guerra et al., 2020). This metric highlights the importance of supporting affordable public transit in U.S. cities to support the household economies of low-income commuters.

Current Status of equity in US transportation planning

According to the Federal Transit Administration (FTA, initially the Urban Mass Transportation Administration, UMTA), agencies operating 50 or more fixed route vehicles serving populations over 200,000 are required to conduct equity analyses such as disparate impacts and disproportionate burden analysis, service monitoring, demographic and service maps and surveys related to demographics and travel behavior (Karner, et al, 2023). The goal for such efforts is primarily to expand the access of all population groups with a particular focus on marginalized populations, as stated in the U.S. Department of Transportation’s Equity Action Plan (USDOT, 2023). USDOT’s intention under equity programs is to empower marginalized populations and help them have a more respected voice in the transportation planning process. USDOT requires state Departments of Transportation (DOTs) and Metropolitan Planning Organizations (MPOs) to regularly perform quantitative equity analyses including an equity screening tool and public involvement in Statewide Transportation Improvement Program (STIP) and Transportation Improvement Program (TIP) projects. These recently developed actions are products of legislative movements in recent decades, including Title VI of the Civil Rights Act of 1964 (Title VI); Executive Order 12898, Federal Actions to Address Environmental Justice (EJ) in Minority Populations and Low-Income Populations; and the National Environmental Policy Act (NEPA) as well as Executive Order (EO) 13985, “Advancing Racial Equity and Support for Underserved Communities Through the Federal Government.” When assessing the equity of transportation services, quantitative equity analysis suggests data-driven processes that assess the ability of the proposed programs and efforts in addressing marginalized groups’ needs. Demographic data on race, income, disability, living arrangement, vehicle ownership and English’s language proficiency are usually collected from American Community Surveys and compared with the distribution of impacts from proposed projects.

The outcome of such efforts has been the development of several equity analysis or screening tools for evaluating plans, which serve to increase the opportunities for a more inclusive approach in transportation planning. Similarly, the birth of University Transportation Centers in 1988 after enactment of Surface Transportation and Uniform Relocation Assistance Act of 1987 is another research-based effort to bring equity in the context of transportation planning research. The Transportation Equity Act for the 21st Century (TEA-21) in 1988 and the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) in 2005 expanded the number of centers nationwide. The Surface Transportation Extension Act of 2010, sec. 411(e)(3), gave the authority to USDOT to allocate funds among centers. Several new acts and policies have been passed since then to bolster equity, environmental justice and inclusiveness in transportation. Under the Infrastructure Investment and Jobs Act (IIJA) enacted in 2021, UTCs are assigned to sustain and establish new and vital efforts in research, education, and technology transfer that benefit the movement and safety of Americans and freight. Concerned with environmental impacts, this act requires the UTCs to conduct research in: 1. Improving Mobility of People and Goods; 2. Reducing Congestion; 3. Promoting Safety; 4. Improving the Durability and Extending the Life of Transportation Infrastructure; 5. Preserving the Environment; 6. Preserving the Existing Transportation System; and 7. Reducing Transportation Cybersecurity Risks (USDOT, 2023b).

Although promoted significantly throughout the nation, these equity assessments have their limitations. In fact, most of the existing methods suffer from aggregation bias, meaning that usually, a geographic unit of analysis (such as census tract or traffic analysis zone) is chosen while assuming homogeneity within each unit of analysis is unrealistic. For this, the development of activity-based models with households or individuals as the unit of analysis may be more accurate. Furthermore, in equity studies, the impacts are assumed to have the same effect on marginalized population, while different people (such as African-Americans vs disabled people) may have completely different needs and desires. Absence of sensitivity analysis (scenario analysis) as well as using catchment (proximity measures) rather than actual usage data (such as ridership for public transit) are some other shortcomings of current equity analyses (Frost & Boutros, 2023).

Environmental Justice in Transportation

Similar to transportation equity, the conceptualization of environmental justice in US is rooted in the Civil Rights Acts of 1964 and can refer to disproportionately impacted by governmental decisions through an environmental context. In the US, environmental justice issues and analysis frequently look at the impacts on people of color, other minoritized populations, and, more recently, low-income groups. Related to transportation issues, environmental justice is mostly concerned with the effects of transportation infrastructure on population. For instance, for a household living close to a main corridor, implementing a light rail service may mean overexposure to noise or environmental pollution. Similarly, a huge highway passing through a town may act as a physical barrier for disabled persons who work on the other side of town and commute by walking. The dominant  car-based transportation planning can translate to no access to jobs for individuals without a private vehicle (Kennedy, 2004).

As mentioned, the concept of environmental justice has been a part of  planning practice since the enactment of the Civil Rights Act of 1964, “Nondiscrimination in federally assisted programs.” This act ensures that no person is denied benefits or subjected to discrimination resulting from programs or activities receiving federal financial assistance. Section 602 of the act requires federal agencies to administer program orders or rules that will align with the act’s objectives (Kennedy, 2004). Poverty, disability, race, English-speaking proficiency and other marginalized identities can all be the subjects of transportation equity practices and studies. Since the Civil Rights Movement, several programs have been developed by federal and local authorities to better connect minority populations or welfare recipients to job opportunities and other activities. Temporary Assistance for Needy Families (TANF) program and the Job Access and Reverse Commute (JARC) grant program are some of the programs aimed at providing job opportunities that are accessible for these populations.

The uneven distribution of environmental advantages and impediments associated with transportation has urged planners to consider allocating costs and benefits of transportation networks (Karner, 2016; Schweitzer & Valenzuela Jr, 2004). From a transportation equity lens, transportation infrastructure improvements and operations (and impacts) should not disproportionately affect low-income households and minority populations (Litman, 2017). Instead, transportation should focus on equitable access and provision. Although transportation systems provide economic and social benefits and opportunities, they may also generate adverse environmental impacts. Environmental conditions and extreme climate events may also affect transportation facilities’ construction, operation, and maintenance. The environmental impacts can be categorized as:

• Direct impacts, such as noise and carbon monoxide emissions
• Indirect impacts, such as particulates resulting from incomplete combustion in an internal combustion engine
• Cumulative impacts, including greenhouse gas emissions (Rodriguez, 2020).

The significance of these impact analyses can be immediate or long-term, especially when cumulative and producing a wide range of impacts overtime if neglected. Recent studies show that a major portion of these impacts are usually produced and experienced in proximity of marginalized populations (Chen et al., 1998; Delbosc & Currie, 2011; Sharifiasl et al., 2023).

The transportation sector is the largest direct source of air pollution and greenhouse gas (GHGs) emissions in metropolitan areas across the globe (EPA, 2024). Idling trucks and cars in traffic congestion increase exposure to carbon monoxide emissions and sulfur dioxide and reduces oxygen intake, which can aggravate respiratory issues such as asthma. Nitrogen monoxide, hydrocarbons, and peroxyacetyl nitrates are associated with respiratory and eye irritations and lung cancer. More research is needed to understand the environmental impacts, such as air pollution and noise levels, on low-income and minority groups that live immediately adjacent to transportation networks.

Environmental justice studies use examine the relationship between income, race, ethnicity, and other socioeconomic factors and pollution rates across different communities (Schweitzer & Valenzuela Jr, 2004). These studies of indirect impacts reveal a higher concentration of airborne particulates in low-income and minority neighborhoods. The disparity is further aggravated because studies indicate that low-income commuters contribute significantly less to air pollution (Bullard & Johnson, 1997). Lower-income households are less likely to own and drive private cars than their higher-income counterparts (Bullard & Johnson, 1997).

In addition, hospital admission rates show that low-income commuters and households suffer health impacts from greater exposure to higher ozone, aerosol acidity, and sulfate concentrations (Rivas et al., 2017). Other findings indicate a high correlation between traffic congestion and pollutants, including benzene, 1,3-butadiene, and diesel particulate matter. There is approximately a three times higher probability that the lowest income groups reside in neighborhoods with a higher concentration of noise and air pollution due to traffic congestion. Yet another study finds a negative correlation between traffic density and household income for all races except for white communities (Houston et al., 2004). Finally, studies that examined different U.S. contexts acknowledge the relationship between public health issues, diseases, and residents in low-income neighborhoods or areas adjacent to major roadways and highways (Schweitzer & Valenzuela Jr, 2004).

Numerous acts and executive orders have sought to mitigate the adverse effects of transportation projects on vulnerable communities (Rowangould et al., 2016). For instance, in 1992, President Clinton issued an executive order (EO 12805) that required all federal agencies, such as the U.S. Department of Transportation (USDOT), to evaluate the impact of transportation projects on low-income communities. In addition, planning agencies at all levels conduct impact assessments and seek to address environmental justice issues. Moreover, the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) promotes public involvement in regional transport plans and requires a commitment to continuous public transit funding. Finally, the Transportation Equity Act for the 21st Century (TEA21), which became effective in 1998, formally and explicitly declared equity a priority for U.S. transportation practices. These orders and acts protect low-income groups and minorities from bearing transportation costs and call for action that allows these communities to enjoy equal benefits (Schweitzer & Valenzuela Jr, 2004).

In addition, the Intermodal Surface Transportation Efficiency Act (ISTEA) broadened the required factors that transportation planning agencies must consider. ISTEA also promotes multimodal transportation and air quality monitoring. This act also empowered Metropolitan Planning Organizations (MPOs) and regional planning agencies in the U.S. to advocate and plan for equity in transportation. This practice is relevant because studies underscore that equity is a serious issue at both regional and metropolitan scales. ISTEA was a turning point in U.S. transportation planning as it relegated several transportation decisions (such as multimodal transport system) to local government and called for the end of highway-oriented development (Abbot & Lowry, 2010).

Local groups, like community-based, faith-based, or other non-governmental organizations, are partners in disseminating information among vulnerable communities. These organizations may assist government agencies in developing more equitable projects under the newest federal transportation reauthorization bill, SAFTEA—Safe, Accountable, Flexible and Efficient Transportation Equity Act (Schweitzer & Valenzuela Jr, 2004).  Other examples of recent transportation equity acts include the Fixing America’s Surface Transportation Act or “FAST Act” (“Intermodal Surface Transportation Efficiency Act,” 2024)

1. U.S. National Blueprint for Transportation Decarbonization

The U. S. National Blueprint for Transportation Decarbonization (The Blueprint) of 2023 has at its foundation the Infrastructure Investment and Jobs Act, which is also called the Bipartisan Infrastructure Law (BIL) from November of 2021 and the Inflation Reduction Act (IRA) from August 2022. By combining these three laws, the United States addresses the environmental impacts of climate change, maintaining a thriving economy, and improving human health, safety, and well-being, especially for those in historically disinvested communities (Office of Energy Efficiency & Renewable Energy, 2023). As the brief video summarizes, the strategies are for a whole-government effort to eliminate greenhouse gas emissions from the transportation sector by 2050 through the collaboration of the Departments of Energy, Transportation, Housing and Urban Development, and the Environmental Protection Agency (USDOE, 2023).

United States Department of Energy (USDOE). (2023, January 13). U. S. National Blueprint for Transportation Decarbonization [Video]. YouTube. https://www.youtube.com/watch?v=RKplZwqFwVk

The Blueprint employs three interconnected strategies to reduce transportation sector GHG emissions. First, it addresses the design and layout of both the transportation system and adjacent land uses to promote greater accessibility to jobs, housing, and services through efficient transportation modes. This strategy enhances the convenience of sustainable transportation options, such as walking and biking, while improving connectivity to opportunities and overall quality of life. Second, the Blueprint focuses on increasing vehicle and engine efficiency to advance decarbonization goals. This includes improving the reliability, affordability, and safety of public transit and other modes of transportation. Finally, the plan promotes reducing reliance on petroleum and other high-GHG fuels. This strategy further strengthens the first two approaches as cleaner fuel options become available for vehicles across the transportation sector—including aviation, commercial trucking, transit, and private vehicles. Successfully implementing these strategies will require a coordinated approach, significant investment, and time. Additionally, the departments and agencies involved are committed to addressing the historical inequities in distributing transportation benefits and burdens, focusing on promoting environmental justice and equity (Office of Energy Efficiency & Renewable Energy, 2023).

Conclusion

This chapter examines the equity and environmental justice implications of car driving for the built environment and people in cities. It reviews the origins and state-of-the-art practices of equity in transportation. This chapter reviews the unfair distribution of transportation burdens across the city, especially for marginalized groups. Finally, this chapter discusses the efforts of the U. S. National Blueprint for Transportation Decarbonization to transform the transportation sector toward more sustainable and equitable operations.

References

Anderson, J. E., Wulfhorst, G., & Lang, W. (2015). Comprehensive analysis of the built environment through the introduction of induced impacts via transportation detailed case study for the urban region of Munich, Germany. Transportation Research Record, 2500, 67–74. https://doi.org/10.3141/2500-08

Arsenault, R. (2006). Freedom riders: 1961 and the struggle for racial justice. Oxford University Press.

Banister, D. (2011). Cities, mobility and climate change. Journal of Transport Geography, 19(6), 1538–1546. https://doi.org/10.1016/j.jtrangeo.2011.03.009

Baum-Snow, N. (2007). Suburbanization and transportation in the monocentric model. Journal of Urban Economics, 62(3), 405–423. https://doi.org/10.1016/j.jue.2006.11.006

Brenman, M. (2007). Transportation Inequity in the United States: A Historical Overview. ABA. https://www.americanbar.org/groups/crsj/

Bullard, R. D., & Johnson, G. S. (1997). New Society Publishers. Retrieved from http://utexas.summon.serialssolutions.com/2.0.0/link/0/eLvHCXMwdZ07C8IwEMcP0UHBQatSX9gvUAlp0rSztgjiVl1LYtOxix38-OZhqgiOIXBcwuV15P87gAjvUfizJ4g0JlTq2wllvBKMcalWWRURJCQVJpNRZCy_xcdLcv5o1x3E0VCTWvm0bMEuf0FoxBA1Sl_1blDBfE27YMZJkhIVjob5GFNdiY454o5rE3XsWLNfZ0o-gb7WGUyhJxsPhk4g_JiBpytsBa2jjpupm8Muz4rDKbSGyrfLpXMuwQsYc_1bvWmNqq3yIaCIC3RnXJDalH_mFZYyNqTAmhFSL8H_Z271v2sNIwtX1QmCDQxqFcBy64b4AteMbQ4

Burgos- Rodríguez, J., Martinez, V., Sperling, E., Nicome, A., and Heaps, W. (2023). Making healthy connections in transportation. Public Roads, 87(2).  U. S. Department of Transportation Federal Highway Administration Publication FHWA-HRT-23-004. https://highways.dot.gov/public-roads/summer-2023/05

Cervero, R., & Kockelman, K. (1997). Travel demand and the 3Ds: Density, diversity, and design. Transportation Research Part D: Transport and Environment, 2(3), 199–219. https://doi.org/10.1016/S1361-9209(97)00009-6

Chen, T.-L., Chiu, H.-W., & Lin, Y.-F. (2020). How do East and Southeast Asian cities differ from Western cities? A systematic review of the urban form characteristics. Sustainability, 12(6), 2423. https://doi.org/10.3390/su12062423

Chetty, R., Hendren, N., Jones, M. R., & Porter, S. R. (2019). Race and economic opportunity in the United States: An intergenerational perspective. Quarterly Journal of Economics, 135(2), 711-783. https://doi.org/10.1093/qje/qjz042

Coolsaet, B. (Ed.). (2020). Environmental justice: Key issues. Routledge.

Delbosc, A., & Currie, G. (2011). The spatial context of transport disadvantage, social exclusion and well-being. Journal of Transport Geography, 19(6), 1130-1137.

Environmental Protection Agency (EPA). (2024, July 8). Sources of greenhouse gas emissions. Greenhouse Gas Emissions. https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions

Environmental racism. (2024, August 18). In Wikipedia. https://en.wikipedia.org/wiki/Environmental_racism

Frost, M. & Boutros, A. (2003). Integrating equity into transportation planning. Public Roads, 87(1) FHWA-HRT-23-003. https://highways.dot.gov/public-roads/spring-2023

Guerra, E., Li, S., & Reyes, A. (2020). How do low-income commuters get to work in U.S. and Mexican cities? A comparative empirical assessment. Urban Studies, 004209802096544. https://doi.org/10.1177/0042098020965442

Houston D., Wu J., Ong P., and Winer A. Structural disparities of urban traffic in Southern California: implications for vehicle-related air pollution exposure in minority and high-poverty neighborhoods. Journal of Urban Affairs 2004: 26(5): 565-592.

Ihlanfeldt, K. R., & Sjoquist, D. L. (1998). The spatial mismatch hypothesis: A review of recent studies and their implications for welfare reform. Housing policy debate, 9(4), 849-892.

Institute for Transportation & Development Policy (ITDP). (2024, January 24). The high cost of transportation in the United States. Transport Matters. https://itdp.org/2024/01/24/high-cost-transportation-united-states/

Intermodal Surface Transportation Efficiency Act. (2024, August 4). In Wikipedia. https://en.wikipedia.org/wiki/Intermodal_Surface_Transportation_Efficiency_Act

Jochem, P., Rothengatter, W., & Schade, W. (2016). Climate change and transport. Transportation Research Part D: Transport and Environment, 45, 1–3. https://doi.org/10.1016/j.trd.2016.03.001

Karner, A. (2016). Planning for transportation equity in small regions: Towards meaningful performance assessment. Transport Policy, 52, 46–54. https://doi.org/10.1016/j.tranpol.2016.07.004

Karner, A. A., Levine, K., Dunbar, J., Pendyala, R. M., & Dunbar Transportation Consulting, L. L. C. (2023). Practical Measures for Advancing Public Transit Equity and Access (No. FTA Report No. 0249). United States. Department of Transportation. Federal Transit Administration.

Kennedy, L. G. (2004). Transportation and environmental justice. In Running on empty (pp. 155-180). Policy Press.

Leck, E. (2006). The impact of urban form on travel behavior: A meta-analysis. Berkeley Planning Journal, 19(1). https://doi.org/10.5070/BP319111488

Litman, T. (2017). Evaluating transportation equity. Victoria Transport Policy Institute.

Mattson, J. (2020). Relationships between density, transit, and household expenditures in small urban areas. Transportation Research Interdisciplinary Perspectives, 8, 100260.

Miller, K. (2018). Introduction to design equity. University of Minnesota Libraries Publishing. https://open.lib.umn.edu/designequity/

Moretti, L., & Loprencipe, G. (2018). Climate change and transport infrastructures: State of the art. Sustainability, 10(11), 4098. https://doi.org/10.3390/su10114098

Newman, P., & Kenworthy, J. (2011). “Peak car use”: Understanding the demise of automobile dependence. World Transport Policy & Practice, 17(2), 31–42.

Norman, J., MacLean, H. L., & Kennedy, C. A. (2006). Comparing high and low residential density: life-cycle analysis of energy use and greenhouse gas emissions. Journal of urban planning and development, 132(1), 10-21.

Office of Energy Efficiency & Renewable Energy. (2023). The U.S. National Blueprint for Transportation Decarbonization: A Joint Strategy to Transform Transportation. U. S. Department of Energy. https://www.energy.gov/sites/default/files/2023-01/the-us-national-blueprint-for-transportation-decarbonization.pdf

Rivas, I., Kumar, P., Hagen-Zanker, A., de Fatima Andrade, M., Slovic, A. D., Pritchard, J. P., & Geurs, K. T. (2017). Determinants of black carbon, particle mass and number concentrations in London transport microenvironments. Atmospheric environment, 161, 247-262.

Sharifiasl, S., Kharel, S., & Pan, Q. (2023). Incorporating job competition and matching to an indicator-based transportation equity analysis for auto and transit in Dallas-Fort Worth area. Transportation Research Record, 2677(12), 240-254.

Spatial mismatch. (2024, February 1). In Wikipedia. https://en.wikipedia.org/wiki/Spatial_mismatch

United States Department of energy (USDOE). (2023, January 13). U. S. National Blueprint for Transportation Decarbonization [Video]. YouTube. https://www.youtube.com/watch?v=RKplZwqFwVk&t=5s

United States Department of Transportation (USDOT). (2023). Equity Action Plan. https://www.transportation.gov/priorities/equity/2023-equity-action-plan

United States Department of Transportation (USDOT). (2023b). University Transportation Centers Program. Assistance Listing 20.701. https://sam.gov/fal/21809c0217e546ddb4a8d360d4bf56bc/view

Weingroff, R. F. (1996). Federal-Aid Highway Act of 1956: Creating the interstate system. Public Roads, 60(1), 10-20.

White flight. (2024, August 9). In Wikipedia. https://en.wikipedia.org/wiki/White_flight