Why Building Transmission Along Highways is Better for Birds

The United States is facing record growth of electricity usage, but the system that delivers electricity to our homes is outdated, increasingly unreliable, and currently cannot support the expansion of renewable energy needed to protect birds. As the U.S. works to modernize and expand the aging electric grid, building new transmission lines along highways can speed up the transmission permitting process while also minimizing risks to birds and their habitats.

We’re making progress. Through Audubon's work with the NextGen Highways Coalition, we have helped pass legislation allowing transmission lines to be built alongside highways in Minnesota, Colorado, and most recently Iowa.

Audubon’s science shows that many bird species are at risk from climate impacts, making renewable energy and expanded transmission capacity essential to protecting bird populations over the long term. Our Birds and Transmission report explains that transmission lines are a critical component of the electric grid. These towering metal structures help move wind and solar energy over long distances from where it’s generated to communities where energy is used.  

Utilizing existing corridors for new transmission lines is generally better for birds than building on previously undeveloped land, known as “greenfields.” Because these rights-of-way have already been cleared and managed for infrastructure like highways and railways, they reduce the risk of additional habitat loss and fragmentation. This approach can also help reduce siting conflicts involving environmental and cultural concerns, local communities, private landowners, and state and federal jurisdictional issues.

Progress in Iowa

Iowa’s recent policy change marks a significant milestone for a state that already generates about two-thirds of its electricity from wind and other renewable energy sources—well above the national average. This new approach positions Iowa to expand its grid while minimizing additional impacts on wildlife habitat. Audubon staff played a key role in the effort by helping advance the policy through Iowa Department of Transportation administrative rule updates and public comment periods in 2025, and the legislative effort in 2026, which Governor Kim Reynolds signed into law in April.

Doug Harr, president of Iowa Audubon, underscored the importance of the shift, noting that “Responsible energy planning is key to protecting Iowa's birds and ecosystems in the long run.” For years Harr has represented Iowa Audubon on committees to improve new transmission line locations, particularly to protect birds from line collisions. “As our state leads the way on renewables, this grid expansion will help deliver that energy to Iowans while minimizing habitat impacts.”

Momentum in Minnesota and Colorado

In 2024, Minnesota enacted legislation opening highways to co-location with high-voltage transmission, reversing a previous prohibition by the Minnesota Department of Transportation (MnDOT).  Audubon staff were closely involved in drafting, lobbying for, and passing the legislation, making sure that bird habitat was considered.

Since the Minnesota legislation passed into law, the Minnesota Public Utilities Commission (MN PUC) has begun asking utilities to explain how they are considering highway right of ways, and how they are coordinating with MnDOT—an incredible shift in just two years.

Also in 2024, the Colorado Electric Transmission Authority (CETA) identified the need for up to $4 billion in additional investment in transmission to ensure that the state's power grid can keep pace with demand. In response, Audubon worked as part of the NextGen Highways Colorado coalition alongside energy, transportation electrification, business, and conservation interests to allow for more coordinated and efficient planning between transportation officials and utilities. Resulting from those efforts, the Colorado Department of Transportation is now an active part of the siting and permitting process.

For Daly Edmunds, who represented Audubon in the Colorado coalition, co-locating along existing transmission lines and highway corridors makes sense on so many levels, especially to minimize habitat loss. "Having a law that prioritizes rights-of-way for transmission development, after existing utility corridors but before new corridors, is a major win for conservation in Colorado,” she says. “Hopefully this will have ripple effects to other states."

The Road Ahead

Efforts on this front continue and Audubon has recently joined NextGen Highways coalitions in Oregon and Washington. We also encourage co-location along existing transmission lines and highway corridors as part of our collaborative work with project developers to ensure that transmission infrastructure is planned with birds and communities in mind. This includes sharing science-based solutions for avoiding, minimizing, and offsetting potential impacts on birds and bird habitat. Co-location is among the valuable strategies that should be considered in order to reduce costs and safeguard critical bird habitat.

Like those passed in Iowa, Minnesota, and Colorado, policies at the state and federal level can do more to reduce barriers to co-location. States and the federal government may even go further by allowing greater flexibility in the use of existing highway funding or creating specific incentives for well-sited transmission projects co-located along highway corridors. Audubon is committed to sitting at the table for these important discussions as the U.S. increasingly incorporates clean energy to reduce carbon emissions and increase grid resiliency.