The Banff Wildlife Crossing Project in Alberta, Canada, is essentially a bridge for animals & has reduced animal-vehicle collisions in the area by more than 80%
Monitoring also shows that different species have different preferences: grizzly bears, deer, moose, and elk favour the open air of the overpasses, while cougars and black bears prefer the cozy coverage the tunnels provide.
The crossings also help maintain genetic diversity in wildlife populations, reconnecting the habitat on either side of the highway and allowing the different groups of the same species to interact.
Parks Canada has some YouTube videos from trail cameras they installed in order to see what wildlife actually uses these and how quickly they started using them once construction was complete. Pretty neat to watch.
Sorry to say I've been in more states than not, and I've never encountered one. To be fair, my kids attend public school in trailers, so, you know, I don't think the deer are gonna be getting amenities any time soon, but who knows?
Im in the US and the county forest preserve system has the opposite for the deer. Tunnels under the roads. People could use them to but they tend to get muddy. I wish it was more like this.
The article doesn't state how big the "area" is, but the employ fences along the sides for quite a ways in order to make it hard for animals to just get on the highways, and that while the 80% is overall, it states that deer and elk collisions went all the way down to 96% less.
I did not know that there were tunnels underneath as well. Are the tunnels at all of the crossings? I know they are just finishing a new one a bit west of calgary.