Seeing R-E-D: Making a Place for Human Ecology in Highway Crossing Design

Whether the first roads were constructed in the Indus Valley or by the Roman Empire is still up for debate. However, there is no doubt about the ubiquity and centrality of roads for modern-day civilization; they enable societies to transport people, materials, products, and even services between what otherwise would be disconnected and often distant places. If there is one defining axiom of the 21st century, it is that people want to be connected with each other, be it digitally or geographically. Consequently, as the world continues to urbanize (and let there be no doubt that we are urbanizing, at a rate of roughly 1 billion more urban dwellers every decade), we will continue to construct ribbons of asphalt that celebrate humankind's ingenuity and freedom from the geographic limitations of bipedal transport. Yet these same passageways for people interfere with safe passing for wildlife. There's the rub. According to the Transportation Research Board, there are more than 1.5 million wildlife-vehicle collisions every year in the U.S., with cost estimates ranging from $5.2 to $8.3 billion annually. The confluence of transport corridors for humans and wildlife can be unsafe for all species involved. The question then is how can we design and provide safe passageway for all species?

The design by the Rosenberg team presents one solution to this dilemma. It takes into consideration the biology and movement of the local wildlife, in this case, elks (Cervus canadensis), black bears (Ursus americana), and lynx (Lynx canadensis), among others, to design safe crossings over Interstate 70 in Colorado. Here it may be worthwhile to recall a bit of U.S. highway history. Before the Interstates crisscrossed the country, the national highway system was made up largely of Numbered Highways, also called U.S. Routes or U.S. Highways. The most famous of these today is Route 66. As any child who has seen the movie Cars will tell you, those numbered highways represented a slower way of life and a slower mode of transport through towns and cities, but the new interstate highways provided people with faster ways to get from Point A to B, and many established towns were completely bypassed by the new routes.

How is this relevant to the discussion about safe passageway for wildlife? As societies continue to lay down thousands of kilometers of tarmac and debate the efficacy of wildlife crossing designs, it may be useful to remember that there are multiple paths and multiple modes for human species to traverse between 2 places. The underlying premise—and the central shortcoming—behind the design by the Rosenberg team, and presumably the other ARC finalists, is that it requires rethinking and re-designing only one side of the human-wildlife confluence. The design is completely based on the ecology of the wildlife, and there is no consideration of the human uses of this space other than taking it as a given. There is no discussion or consideration of how the roadway could be re-envisioned or redeveloped such that the human desire to cross Colorado could be reconciled with the needs of local wildlife. A more holistic approach would consider how design could also alter human behavior through these wildlife corridors.

Moreover, there is an assumption that simply by building the crossing bridge over the highway, it will provide safe passageway for wildlife. All the designs (noise attenuation, high beam shading, etc.) require no modification of human driving behavior. And yet, the roadway could be redesigned or revamped to increase the likelihood of success of the bridge. Not considering possible changes to human behavior is a mistake. It misses an important opportunity to both educate the general public driving through the area and to provide better passageway for wildlife. Without altering human behavior (through design or otherwise), we will forever need to think of new ways that other life on Earth can have safe passage. Furthermore, it is likely that over time, the growth of vegetation cover and leaf debris will negatively affect the navigability and visibility of the highway, and that...