On the Road: Rethinking Freeways—and the Spaces Alongside Them
The open road, a long stretch of highway ahead, nothing to the left or right except a smattering of plants and perhaps some roadside debris. Is this Kerouacian vision of freeways romantic, or outdated? What if the underutilized space alongside freeways could be repurposed into something more intentional, offsetting the problems freeways themselves create? Here, NBBJ Principal and landscape architect Tony Murry offers ideas for carbon sequestration, urban agriculture and energy harvesting that can be implemented to support both environment and community.
Those of us who live outside of cities, in suburban or rural areas—as I do in Columbus, OH—experience a version of this scene every day: a long stretch of highway on the drive to work, sometimes populated by nondescript, overgrown plants or trees, or sometimes nothing at all. What’s more, when a highway needs to be expanded, rerouted, or when other transportation-related construction must take place, whatever greenery that might be present is quickly removed. Residual all along, it has now become a casualty. I often find myself asking, “What if there were a way to use these areas along highway interchanges in a more intentional way?”
Opportunity is ripe to transform these “extra” spaces alongside freeways, either optimizing them for the service they performed in the first place—carbon sequestration or stormwater management—or thoughtfully repurposing them for urban agriculture or solar energy. Here, I outline functional solutions for these spaces, from small-scale changes to large-scale interventions, to benefit the environment and, by extension, the community.
Counteract Carbon Emissions
Ironically, efforts to repurpose space alongside freeways into something useful stem from the very problems freeways themselves create: pollution, carbon emissions and the destruction of natural resources. Greenhouse gas emissions from transportation account for about 29% of total GHG emissions, and vehicle traffic—and especially traffic congestion—also degrades ambient air quality and contributes to increased morbidity and mortality for drivers and those living near crowded roadways.
Instead, imagine a wetland reserve located within walking distance of any downtown metropolis, with access to native plantings, walking trails, bird watching, and art. For example, the interchange of I-70 and I-71 in Columbus, OH, takes up about 40 acres of space adjacent to downtown and the Scioto River. This space could easily be connected to the downtown parks system, recreation facilities, a river corridor, and several underserved neighborhoods, becoming a hub of natural landscape opportunities that also actively filters freeway runoff and promote biodiversity.
If such large-scale intervention is not possible, plants that sequester carbon can be placed along roadways to counteract highways’ effect on air quality. In addition, green infrastructure solutions, such as systems to capture or manage stormwater runoff, can also contribute to environmental impact. These can be as simple as large cisterns at the end of a downspout for water reuse, or more complex, such as an engineered wetlands system designed to naturally filter freeway runoff.
Urban Growth
Repurposing highway shoulders or medians to support urban agriculture can ensure that groups living near highways—in many cases, underrepresented communities who already experience health and financial inequity—have access to and education around healthy food.
Of course, safety and access are critical to the success of this idea, and highway design would need to evolve beyond prioritizing the car to considering pedestrian access, tunnels and trails as well as safe distances and barriers. But imagine a dad able to walk with his kids to a large urban garden to pick up fresh produce or manage a rented plot. Or a brewery looking for sustainably harvested local hops with a good back story—maybe their latest brew is called “Off Ramp IPA.” To ensure safety and health of crops and people, urban agriculture is perhaps better suited to areas below interchanges or underpasses, while the areas next to roadways could be utilized for stormwater management or other purposes.
Not all highways are located near underserved communities—many serve rural, corporate or industrial areas. Changes to how freeway shoulders are used can benefit all communities. For example, a recent vacation road trip out west revealed to me that some farmers already use these spaces for agricultural. In places like Missouri, Nebraska, South Dakota and Wyoming, grass alongside the freeway is harvested to feed livestock, benefitting local ranchers and saving taxpayer dollars on maintenance.
Solar System
Cross country infrastructure for electric vehicles (EV’s) needs to grow to meet the needs of an increasingly EV-centric future. The IEA reports that electric car sales exceeded 10 million last year, up 55% from 2021, and over just five years, EV sales increased from around 1 million to more than 10 million. At the same time, many of these freeway spaces represent land that is available, accessible and proximate to this emerging market. Therefore, the use of freeway shoulders to harvest solar energy makes even more sense when we consider how many electric vehicles will soon be on the road.
Associated solar panels or windmills could supply needed energy and reduce reliance on fossil fuels. What’s more, the average lifespan of a solar panel is roughly 30 years, as is the average lifespan of a freeway. This parallel use and timeframe makes highway shoulders an ideal spot for harvesting solar energy.
Many solutions around the repurposing of underutilized space near highways and roads have, in recent years, focused on the urban experience. Places like New York’s East River esplanade and High Line are often cited as examples of the successful repurposing of transportation infrastructure into community resources. However, what we’re proposing is something different—these wide swaths of land, whether in rural, suburban or urban environments, can be repurposed to support the environment and, in turn, the community.
