In a landmark moment for conservation and road safety, the world's largest wildlife overpass has officially opened in the United States following a major £11 million infrastructure project.
A Colossal Crossing for Conservation
The newly unveiled structure, known as the Greenland overpass, spans the busy Interstate 25 in Colorado. This remote yet heavily trafficked corridor connects the cities of Denver and Colorado Springs. The bridge's primary mission is to provide a safe passage for a diverse array of local fauna, including elk, mule deer, black bears, and mountain lions, over six lanes of constant traffic.
Transport officials report that approximately 100,000 vehicles use this stretch of road every day, making animal crossings perilous. The overpass, measuring an impressive 200 feet wide and 209 feet long, is designed to seamlessly link 39,000 acres of crucial wildlife habitat that were previously severed by the highway.
Engineering for Safety and Instinct
Shoshana Lew, the Executive Director of the Colorado Department of Transportation, emphasised the dual-purpose of the project. "The I-25 Greenland wildlife overpass is critical to the safety of both wildlife and motorists," she stated. The crossing is a central part of a broader system expected to reduce dangerous wildlife-vehicle collisions by a staggering 90%.
The success of such structures relies on guiding animals to them. Authorities are using "exclusionary fencing" – tall barriers that run alongside the highway. This fencing prevents animals from attempting a risky road crossing and gently directs them towards the safe route of the overpass instead.
Evidence from similar projects, like those monitored by the Arizona Game and Fish Department, shows that animals quickly learn to use these dedicated crossings. Remarkably, this knowledge is then passed down through generations, creating a lasting cultural shift in animal behaviour.
A Global Benchmark in Green Infrastructure
This project, completed in December 2025, sets a new global standard for green transport infrastructure. By investing in substantial wildlife bridges, planners are addressing two pressing issues: the protection of vulnerable animal populations and the enhancement of human safety on roads that cut through wild landscapes.
The opening of the Greenland overpass represents a significant step forward in reconciling the needs of modern transportation with the imperative of ecological connectivity. It serves as a powerful model for other nations, including the UK, where fragmenting habitats due to roads remain a key conservation challenge.
