While crossing a pedestrian bridge in the middle of a big city...

...I recalled this comment made by Ted Zoli, a structural engineer:

"We spend $8 billion a year running over wildlife. If we took that cost and quartered it, we could build 200 animal crossings a year, and the problem of roadkill would disappear within a generation.

Europe has lots of these crossings for wild animals, and they appear to be very effective, reducing "roadkill by as much as 90-100%." The reason we have so few crossing structures in the US?

“We could easily say today that wildlife crossings are no longer design or technical challenges. We have every capacity to implement these structures. What we really need is political, economic and social leadership.”

So it's only the powers of unreason that prevent us from building these beautiful crossings that are good for animals in the woods and animals in cars.