Skip to main content

There’s a climate cost to America’s freeways, and it’s not paid equally

A freeway laces through Seattle as smog descends on the city's skyline

The environmental impacts of the Interstate Highway System continue to harm communities of color through health hazards, pollution, and displacement.

A freeway laces through Seattle as smog descends on the city's skyline
A highway snakes through Seattle, Washington (Flickr photo)

The sprawling roadway network of the Interstate Highway System (IHS) is a ubiquitous feature of life in America. Long drives along vast stretches of freeway have come to symbolize mobility and freedom in cultural memory, obscuring the insidious nature of the creation of the highway system and its legacies of environmental racism and inequality.

These legacies are not abstract; they have tangible effects in terms of pollution, population displacement, and environmental degradation. To illustrate this point, we’ll start with a story.

The community of Shiloh in Coffee County, Alabama

Highways can endanger lives by exacerbating negative health and safety outcomes. This is exemplified in the ongoing injustices against the predominantly Black community of Shiloh in Coffee County, located in the rural south of Alabama, where the expansion of Highway 84 from 2 to 4 lanes has compounded flooding impacts for the residents. Completed in 2018, the highway expansion project elevated the roadway significantly higher than the existing terrain and neighborhood.

When it rains, the water from the highway is diverted towards people’s homes (as you can see in this video from ABC News) as pipes in the drainage system are pointed in the direction of the neighborhood. Paved roadways are also particularly impervious to stormwater and create substantial run-off, which picks up additives such as rust, metals, and pesticides. The Shiloh community consistently experiences flooding, and with heavy rain becoming increasingly frequent due to climate change, the situation is only expected to worsen. Flooding has affected the structural integrity of homes and is raising alarming health concerns with residents reporting the appearance of mold. Physical damages and rising maintenance issues have forced the Shiloh community to contend with the difficult reality of investing in expensive repair projects or leaving their homes.

The Shiloh community has been working to bring awareness to the plight and adversity they have been experiencing for the past 6 years, in a political landscape that has largely neglected to address the severity of the environmental disaster created in their backyard. Alabama DOT (ALDOT) continues to maintain that no discrimination took place when they planned the highway widening project and that the flooding is not a consequence of the expansion. Following community complaints, three residents received settlements of $5000 or less in exchange for restrictive covenants on their property that release ALDOT from any responsibility of flood damage, which is the extent of any action taken by the state.

Robert Bullard, popularly known as the “father of environmental justice,” has also been collaborating with the community to demand accountability at the federal level. Their efforts culminated in an ongoing civil rights investigation from the Federal Highway Administration (FHWA) and a visit from the U.S. Secretary of Transportation Pete Buttigieg in early April of this year. But so far, no real relief has been found. The residents that signed away their rights feel misled and misheard, with the fear that their homes—and all the wealth and history they hold—are being washed away.

A compounding price

While the community of Shiloh’s case is an extreme example, countless communities across the country are harmed by existing highways and highway expansion projects. The highway system was constructed in a way that cut through vibrant existing neighborhoods, plowing through the heart of communities of color. This build-out of infrastructure cemented racial divides and segregation, encouraging connectivity for certain communities at the expense of others.

Inequities produced by the highway system are reinforced daily, with communities neighboring freeways bearing a disproportionate share of environmental harm. The siting of highways has historically exposed low-income communities and communities of color to higher amounts of air, water, and noise pollutants which in turn produces higher risk for disease and illness. Research indicates that there is a higher exposure to air contaminants for these communities which increases risk for cardiovascular disease and lung problems, among other health concerns. Proximity to paved surfaces, which absorb more heat than natural surfaces, means that communities are subjected to extreme heat as well.

A man in a cowboy hat walks down the sidewalk next to a row of parked cars in Little Village, Chicago
Little Village, Chicago (Wikimedia Commons)

Residents of Little Village, a predominantly Hispanic community in Chicago, have had to contend with poor quality air as a constant feature of their neighborhood that is located in close proximity to Interstate 55. Despite this, a proposal was introduced to add new lanes to the highway, incentivizing increased traffic, leading to a higher concentration of air pollutants in the region and a litany of detrimental health effects. Similarly, a controversial expansion of I-45 in North Houston is set to start soon, which would displace communities and add to existing problems of air pollution.

One of the regulatory tools that the public has at their disposal to challenge administrative actions is the National Environmental Policy Act (NEPA). Enacted in 1970, NEPA requires agencies to produce detailed statements on the environmental impacts of a project, potential actions to mitigate damage, and alternative projects with lower impact. Periods for public comment are integrated into the process as opportunities for affected communities to raise concerns and ensure that their considerations are involved in the decision-making process. Although NEPA gives the public a platform to voice their concerns about projects, it is not designed to stop these projects from being implemented, even if they may cause significant environmental harm. This means that infrastructure projects, such as highway construction and expansion, can continue to move forward even when the repercussions on environmental justice are clear.

Recent research and analysis conducted by T4A has found that trends of highway expansion are continuing to stay the same. Funding is being moved towards emissions-increasing roadway widenings at a critical moment in the climate crisis when our dollars should be spent towards robust public and alternative transportation options. Our transportation system is steeped in environmental racism and continues to function as a driver of inequality. It has created countless socio-economic benefits for certain communities at the tremendous expense of others. Changing weather patterns have also unearthed the fragility of our transportation networks and the need for resilience to allow them to withstand vulnerability.

As the current administration works towards building a future for transportation infrastructure that is equitable and sustainable, it is presented with an opportunity to radically redress historic inequities and meaningfully change how we invest our federal transportation dollars and prioritize who we invest in. Our report, Divided by Design, explains further. Read it here.

VIDEO: How an obscure federal measure justifies the hefty price tag of destructive, divisive roadway projects

Still shot of a busy highway with the text "Value of Time" emblazoned across it on a blue banner

Our newest video, part of Divided by Design, helps explain how federal guidance known as value of time gets used every day to justify the cost of building incredibly expensive highways (or additional highway lanes) that divide our communities, produce more congestion and pollution, and ultimately make it harder to get around in nearly every way.

Our new Divided by Design report examines how the transportation models, policies, and practices we use today took root in the highway era, and they continue to inflict the most harm on people of color. Value of time is just one example of the outdated tools transportation planners and engineers use today that perpetuate harm.

When moving vehicles quickly on all roads is the number one goal for transportation agencies, agencies focus on time savings to drivers at the expense of nearly every other type of user or activity. Value of time encourages agencies to increase speeds and eliminate congestion at all costs, but its emphasis on vehicle speed alone ultimately leads to longer trip times and divided communities.

It’s time for a more equitable approach to transportation. Watch our new video, and read our report Divided by Design.

Divided by Design: Quantifying the damage of our transportation program

Our new report examines the racist roots of our current transportation system. Most importantly, it demonstrates how today’s policies and practices were shaped by the past, leading to racial disparities today. Without a fundamental change to the overall approach to transportation, today’s leaders and transportation professionals, no matter their intent, will perpetuate and exacerbate the damage.

Beginning in the 1950s, highways devastated communities of color and changed our cities forever. But the consequences continue, even as we begin to acknowledge our past mistakes.

To create a better system, we can’t settle for small changes. We need a total shift in approach. To learn more about the report and our analysis, join our webinar on July 25 at 2 p.m. ET.

Read the report

Register for the webinar

A guide to this report

Part I examines the damage and inequities deliberately created by and in the federal transportation program from ~1950 onward. It concludes with a unique analysis of both an unbuilt and built highway segment within Atlanta and Washington, DC to quantify what was lost, who bore the brunt of the damage, and what could have been lost with highways that were never built.


Part II examines our current transportation program to demonstrate how the programs, standards, models, and measures have their roots in the previous era and exacerbate inequities—whether intentional or not.


Part III outlines what needs to change—concrete steps we can take to fundamentally reorient the program around unwinding those inequities.

Two cities divided

Divided by Design also quantifies the damage caused by highways in two U.S. cities: Atlanta, GA and Washington, DC. Like hundreds of others in the U.S., these cities are forever scarred by highways that demolished communities of color, robbing them of opportunity and potential.

Atlanta’s I-20 displaced over 7,500 people and destroyed 1,400 occupied homes. In DC, I-395/695 displaced over 5,000 people and demolished 2,200 homes. These numbers only scratch the surface of the full damage and dislocation.

More significant damage was also avoided in these cities. To understand what might exist in these communities if they hadn’t been disrupted by highways, we looked at two planned highway segments that were never built and the hundreds of businesses, office buildings, and homes that wouldn’t exist today. Click to read these stories:

The damage continues

The models, policies, and practices we use today took root in the highway era, and they continue to inflict the most harm on people of color. Our approach leads to worse health outcomes, greater congestion, and deadlier roadways. It leaves millions of Americans without access to reliable transportation options to get where they need to go. We can’t build a better system on a rotten foundation. It’s time for a paradigm shift.

We need a new approach.

Read Divided by Design

Explore the report’s full content—jump to one of the three parts with the graphics below.

report cover graphic showing a stylized highway cutting through a city.graphic showing a stylized scene of construction of a highway through a city neighborhoodgraphic showing a stylized scene a few blocks away from a highway running through a city neighborhoodgraphic showing a stylized scene of what a neighborhood could look like after tearing a highway down

Don’t miss supplemental maps, videos, and animations in the DC and Atlanta case studies which are not in the hard copy. Download a PDF version of the report.