Demand for electricity in the United States is expected to grow by 50 percent over the next 25 years. This historic surge means that our power grid must be ready to meet Americans’ needs — with more high-voltage transmission to bring electricity from where it’s generated to where it’s used.
Siting transmission requires navigating social, environmental, and other constraints to find viable routes. This process takes multiple years, and where public opposition is strong, it can slow or stop projects altogether. To build a modern grid, we need places to site transmission where there will be lower impacts on agriculture, the environment, on communities, and private property. NextGen Highways was launched because we believe there’s an easy way to do this: by making use of the existing rights-of-way along the nearly 49,000 miles of the U.S. Interstate Highway System. Just as our interstates move people and goods around the country, they can also help move the electricity we need.
Because interstate highway rights-of-way have already been permitted, we can build transmission lines alongside the highways, avoiding the unnecessary use of eminent domain or environmental disruptions to undisturbed land. However, due to outdated regulations, most U.S. states continue to prohibit or severely restrict the co-location of electric transmission lines in interstate highway rights-of-way. The map below shows where that’s still the case. NextGen Highways’ first goal is to persuade states to remove those prohibitions.
What exactly do we mean by co-location? Any infrastructure laid out in a linear fashion — highways, pipelines, or electric power lines — requires a right-of-way of controlled, managed land. In some cases, multiple types of linear infrastructure can share a right-of-way and be built side by side, or co-located, for short or long distances.
Why Co-Locate?
In response to fast-growing demand for electricity to power homes, vehicles, data centers, and industrial needs, the electric grid is undergoing historic investment. That means we need to build bigger and longer transmission lines. Use of long-distance, continuous stretches of land between cities, where highway infrastructure already exists, can speed up the process by which transmission is permitted — historically a choke point in the development of the grid. Co-locating another kind of linear infrastructure along these rights-of-way is the most efficient use of this space.
The good news for states is that this work is already being done successfully. Wisconsin’s state Department of Transportation (DOT) has permitted over 28 projects safely co-located in state and interstate highways rights-of-way, totaling over 200 miles of transmission lines. And Minnesota and Colorado have recently passed laws lifting their prohibitions on interstate co-location, giving them opportunities to use these valuable sites to build out much-needed transmission.
Where and Why Is Co-Location Restricted?
Most states already allow co-location on state highways; the prohibitions and restrictions we’re discussing here tend to apply to interstate highways and other federally funded highways. State statutes or state DOT policy guidelines specifically place the greatest restrictions on longitudinal utility installations within interstate highway rights-of-way.
The policies today across much of the country date to when the Interstate Highway System was first built, and were put in place with a focus on public safety. U.S. DOT policy created a blanket prohibition on all utility co-location, with exemptions to be considered on a case-by-case basis by the Federal Highway Administration. These policies, codified in the 1950s, began to be loosened for telecommunications infrastructure in the late 20th century to serve evolving public needs.
In 2021, U.S. DOT issued a memorandum clarifying its policy on co-location, affirming that states can allow utilities to co-locate infrastructure in interstate highway rights-of-way. But the memo noted that state DOTs retain authority to make final decisions, and state policies prohibiting co-location are still widely in place. The policy of the American Association of State Highway Officials (AASHTO), after which many state DOTs model their own policies, continues to recommend that states only allow co-location as a last resort.
Today, the public’s needs are changing again. We need a bigger, stronger, more resilient, and ultimately more affordable grid to power the modern American economy. Unlocking the unique value of interstate infrastructure corridors through co-location will require innovation, thoughtful collaboration, and policy change in states. Now is the time for utilities, DOTs, other state agencies and stakeholders to work toward more common-sense transmission siting solutions.