Opposing I-11

The Highway to Habitat Destruction, Climate Catastrophe and Wasteful Spending

Arizona already has more than 144,900 lane miles of road. That’s enough pavement to stretch across the United States 54 times. The proposed Interstate 11 — which would run from the state’s border with Mexico north to Wickenburg, Arizona — promises an unnecessary and disastrous addition of hundreds more miles of concrete.

I-11 would degrade or destroy habitat in sensitive desert ecosystems, risking the survival of species like state-protected Sonoran desert tortoises, federally protected Pima pineapple cactuses, imperiled cactus ferruginous pygmy owls — proposed for Endangered Species Act protection — and federally protected riparian birds like Yuma Ridgway’s rails. The highway would disturb hundreds of archaeological and cultural sites significant to several Arizona tribes and lead to more wildfires by helping spread invasive buffelgrass.

Along its proposed path through undeveloped desert, I-11 would also take a toll on public lands, the climate and air quality. Imagine the sights, sounds and fumes of its traffic speeding across a dozen lanes alongside Saguaro National Park, Ironwood Forest National Monument and Sonoran Desert National Monument. It would harm cherished landscapes, wildlife corridors, wilderness areas and Important Bird Areas while completely undermining decades of conservation efforts by the Center, our allies, and state and federal wildlife agencies. It would bring light pollution, destroying famously dark skies, and forever change the ecological and tourism value of this part of the U.S. Southwest.

With an estimated construction cost of $7.3 billion, I-11 would spur massive sprawl that would worsen climate pollution while lining the pockets of the rich real-estate developers driving this project. It would leave Arizona poorer by depleting groundwater and harming public lands and wildlife. Regular Arizonans would never see a real return on investment from this expensive interstate project.

Alternatives to I-11

Interstate 11 is an outdated, 1960s solution that would only exacerbate 21st-century problems. And while it can be difficult to think beyond projects that reinforce car and concrete dependency, we’ll never tackle our climate, environmental and social challenges until we do.

Right now Arizona’s transportation system is stuck in a rut. To get out, we need to divest from polluting highways and increase investment in green transportation infrastructure that integrates multimodal transportation systems. We need to protect wild spaces and water supplies, as well as advance sustainable community development and climate resiliency in existing communities.

Accordingly, the Arizona Department of Transportation should improve transportation and alleviate congestion within Phoenix and other rapidly growing areas — not promote urban sprawl. Most of Arizona’s population growth is concentrated in the Phoenix metropolitan area, which has absorbed 78% of all the state’s population growth since 2000. According to a study by the Arizona Commerce Authority, Phoenix will account for 83% of the state’s population growth over the next 20 years.  

A new 280-mile interstate running through undeveloped desert and designed for long-distance, interregional travel outside of Phoenix won’t sustainably address the city’s concentrated-population problem. Federal Highway Administration studies show that 73% of U.S. vehicle trips cover fewer than 9 miles, and the average commute is 12.7 miles.

There are more sustainable and efficient alternatives to I-11 that would address Arizona’s largest transportation challenges. For the major metropolitan areas of Phoenix and Tucson, those alternatives include the expansion of transit services (like rapid and express bus lines and more frequent bus service), more and better bike lanes, light rail, and the creation of a passenger rail along the existing I-10 corridor between the two cities.

Ultimately, I-11 would drain resources from the communities that need them most. Every dollar spent on the interstate could be spent on improving infrastructure where people already live.

Our Campaign

The Center has fought for decades to protect the biodiversity and public lands of the Sonoran Desert. As a member of the Coalition for Sonoran Desert Protection, we’ve supported the Sonoran Desert Conservation Plan created by Pima County in 1998, as well as the Ironwood Forest National Monument, which protects 129,000 acres of beautiful and rugged Sonoran Desert habitat. This work has helped create landscape-level protections where more than 470 species and subspecies of plants, 177 vertebrate species, and 821 invertebrate species thrive.

Despite years of advocacy opposing any route for I-11 that would harm biodiversity or public lands, in 2021 the Federal Highway Administration approved an environmental impact statement that would let I-11 run directly through undisturbed and sensitive desert ecosystems.

In response, in 2022 the Center and three other conservation groups sued to challenge that approval.

We stand opposed to the fragmentation and destruction that I-11 would bring to public lands, endangered species and many years of conservation efforts. Check out our 2023 report Deadpool Highway, which shows that I-11 would spur dramatic population growth and an unsustainable increase in water demand.

Check out our press releases to learn more about the Center's actions to oppose I-11.

Cactus ferruginous pygmy owl by Sky Jacobs.