Late last year, Arizona’s two U.S. senators announced the state would be getting around $24 million to build nearly 17 miles of wildlife fencing along I-17; the fences aim to help prevent animal-vehicle crashes.
The money comes from the bipartisan infrastructure law approved by Congress and signed by President Joe Biden in 2021. That measure includes the Wildlife Crossing Program, which sets aside $350 million nationwide for projects to prevent these kinds of collisions.
The issue is one Ben Goldfarb has thought about a lot. He’s an environmental journalist, and author of the book "Crossings: How Road Ecology is Shaping the Future of our Planet." He joined The Show to talk more about this.
Full conversation
MARK BRODIE: Ben, what got you thinking about the ways roads impact, not just people getting from say point A to point B but have maybe a bigger impact on ecology and the environment?
BEN GOLDFARB: Yeah, you know, as, as an environmental journalist, I often find myself covering the concept of habitat connectivity. Basically the idea that animals need to move across large landscapes to find all the things they need, they need food and they need shelter and they need mates, right. And often, you know, our infrastructure in towns and farms and so on gets in the way of that.
So, you know, about a decade ago, in the fall of 2013, I was in Montana writing about this, this idea of sort of habitats and linking landscapes so that animals like elk and moose and bears can kind of wander unhindered. And, you know, Highway 93 in Montana was kind of getting in the way of that. And I had an opportunity to go on to this wildlife overpass that had been built to allow animals to safely cross this, this highway. And it was just so inspiring to be on top of this, you know, this beautiful graceful bridge crossing the highway.
You know, we do so much on this planet to make animals lives harder and more dangerous. And here was, you know, this infrastructure, we'd spent millions of dollars on to make their lives a little bit easier and safer. And, you know, I just found that to be kind of an inspiring and beautiful idea and it got me thinking more about how roads impact nature and what we can do to kind of manage those impacts.
BRODIE: How prevalent have those kinds of crossings become in terms of overpasses, underpasses, bridges, tunnels, things like that for wildlife specifically?
GOLDFARB: Yeah, they, you know, they, they, they've become much more prevalent and they're still not prevalent enough I think is, you know, sort of the, the two-part answer, I mean, at this point, you know, there are probably a couple of thousand of them around, around the country and everything from overpasses for antelope in, in Wyoming to, you know, little culverts for frogs and salamanders in, in Vermont.
So they're certainly out there, you know, Arizona is actually sort of a, a kind of a great case study and, and how effective they can be. There are a number of underpasses with fences alongside, guide them for elk on the, on the Highway 260 in Arizona and those, you know, those structures have been really effective.
They've reduced crashes by or at least elk collisions by, you know, around 90%. And they've paid for their own construction costs by preventing these dangerous, expensive large animal crashes. So, you know, certainly that's, that's a great example of how well they can work. But at the same time, you know, we need many more of them because there are lots of animal collision, hotpots that are not addressed.
BRODIE: Yeah. Well, so mentioned that, you know, these can cost millions of dollars. And, you know, it seems as though when a project like this is proposed, at least there's some segment of, of the population that will kind of mock it saying like, hey, why are we spending so much money so elk can cross the highway or so, you know, frogs and toads have a, you know, a place to a place to cross the road? Do you find that in, in places where this maybe isn't happening as quickly as it could, is that kind of an impediment to making it happen?
GOLDFARB: Yeah, it's def, it's definitely an impediment. I mean, it's, it's certainly an impediment for those smaller animals now, right. And at this point, you know, again, as I, as I said, the great thing about these wildlife crossings is that they, they do often pay for themselves when they're built to help large animals cross the highway, right.
I mean, the average deer collision now costs society more than $9,000 in, in vehicle repairs and hospital bills and tow truck expenses and so on. You know, the average elk collision is more than $20,000. The average moose collision is more than $40,000, right. So these are really, again, dangerous, expensive events and, you know, by building fences and crossings that prevent them, you know, we can, we can really save the public a lot of money.
You know, the problem is, is when it comes to the smaller animals, right? Nobody's ever, you know, totaled their car running over a, you know, a rattlesnake or, you know, a frog or something. So, you know, those can be harder to justify from, you know, kind of a direct cost benefit standpoint. And, you know, those are the projects that don't get built enough probably. And you know, get mocked when, when they do get built, as you said.
BRODIE: Are there other benefits for the animals or maybe for the environment in general of these kinds of projects other than giving animals a safe passage across the road and maybe reducing, as you say, collisions between vehicles and these animals?
GOLDFARB: Yeah, you know, I think, I think one really important thing to remember is that the collision itself is just part of the way in which the highway is affecting the animal, right? You know, animals, as I said earlier need to move across these, these big landscapes to find everything they, they need. You know, that's especially true in Colorado, where I live in, you know, other states like Wyoming and it's, you know, it's true in, in Arizona as well.
You know, and there are some really tragic instances of, you know, big interstate highways that have basically prevented herds of mule deer and elk and Pronghorn and other animals from, you know, migrating across these large landscapes.
And, you know, in, in Wyoming, for example, we've seen herds of mule deer actually starve kind of en masse, not because the cars hit them, right, but because the kind of, the constant traffic of a big interstate prevented them from getting to these, you know, low elevation winter ranges that they need to reach, you know, during the snowy months to survive.
So, you know, in some ways that that's almost worse than the, than the roadkill itself, right. You know, a herd of mule deer can survive a few collisions. What they can't survive is losing access to all of that, that habitat. So that kind of moving fence effect of traffic is a really huge problem.
BRODIE: Right. When you talk about animal crossings over roads and highways, is it possible to build them so that multiple species are able to use them? I mean, you talked about, for example, a bridge in Arizona for elk, I mean, is it possible that other animals could use that as well or do, do different kinds of animals need different kinds of crossings?
GOLDFARB: Yeah. You know, I mean, certainly it's possible to design crossings that, you know, that benefit multiple species and, you know, those, those underpasses for elk in, in Arizona have been used not only by elk but by, you know, by deer and and mountain lions and bobcats and all, all kinds of, all kinds of critters, you know. But you're right that each species sort of requires different, you know, habitat features to, you know, make it, make it appealing to them.
BRODIE: It's interesting that you bring that up because like in thinking about this, you know, I, I can imagine designers designing these crossings and engineers and, and builders building them. But then the question is, how do you get the animals to use them? Like you obviously can't put up a sign for the animal to say, hey, this is a safe place to cross the road so you don't get hit.
So it sounds like what you're saying is like in, the designers and the engineers have to make it really appealing to the animals to sort of check it out and, and then they kind of figure it out from there?
GOLDFARB: Yeah, I mean, the, the crossings themselves definitely have to be appealing. But, you know, part of that is also the fences that run along the crossings, right. You know, the animal is trying to cross the road, it hits the fence, it kind of walks along the fence line looking for a place and, you know, all of a sudden it, it bumps into that, you know, that, that good looking crossing.
So when they built those elk underpasses on, on state Highway 260 in Arizona, you know, at first they just built the underpasses without any fences. And that actually didn't help, you know, wild collisions did not go down until they added the fences to guide the animals to the crossing. So the fences are a really important part of it.
But the other cool thing that happens over time too is that, you know, as the animals cross at those crossings repeatedly, you know, they actually create little game trails, you know, little animal footpaths and, you know, animals follow animal trails. And so it's like all of the, all of the animals together are sort of learning collectively how to, how to use these things.
