Largest Wildlife Bridge Spanning 10 Lanes of CA 101 Is Nearly Complete
26 comments
·June 18, 2025sameline
For those interested in learning more about road ecology, Crossings is an interesting read.
jedberg
I grew up in Agoura Hills, it's funny to see this on HN of all places. And in another amusing twist, I just drove under this two days ago because I am visiting my parents this weekend.
It's something the locals have known was needed for a long time, I'm glad they were finally able to get it built.
ourmandave
I would pay stupid money to have America change the lyrics to Ventura Highway to include the overpass and then perform it at the ribbon cutting.
Like Elton did for Diana with Candle in the Wind.
ksec
I had to google and double check there isn't another place in Europe called Santa Monica Mountains. Because building bridge for Wildlife seems very European rather than American, or at least modern American. I remember a lot of them in Holland and other places.
Let's hope more of these get built in US. ( While not being crazy expensive )
derektank
Many places in the US have already built dedicated wildlife crossings. There's the Keechelus Wildlife Overcrossing over I-90 in Washington state and Wyoming has invested in several smaller scale over and underpasses along Highway 191
vondur
Ha, this is California and it cost 92 million US dollars
bruce511
More interestingly is the timeline. Broke ground in 2022, finished in 2025, and likely operational before the end of the year.
Now sure, it likely took some years in the planning as well, but it shows that infrastructure can be built in reasonable time lines when politics and nimbyism don't get in the way.
And this isn't a simple bit of construction- it spans a serious bit of active highway.
jonstewart
Introducing wolves back to a relatively small part of Wisconsin has had a positive economic impact from reduced car crashes with deer. This crossing will no doubt help the cougars, and that’ll help the humans who have to drive on this terrifying part of the 101.
https://wolf.org/media-releases/new-study-shows-wolves-save-...
WD-42
SoCal is a lost cause. Paradise lost. But i applaud the effort anyway.
wwweston
There’s still plenty of great landscape to preserve and wander around the metro area ( at least as long as it doesn’t get sold off by venal hacks like Mike Lee).
erulabs
The book “the lion in the living room” documents P-22 and LAs love for the cat very well, it’s a great read and I recommend it.
As much as I’m happy about this I find myself skeptical that wildlife will learn to use it. Do animals walk along the side of the highway looking for openings? Have there been any studies on the efficacy of these wildlife bridges?
xnx
> Do animals walk along the side of the highway looking for openings?
There's precedence in the natural world. A single log can get a lot of use by all types of critters: https://www.youtube.com/watch?v=qsDU_tTgsFw
ahoef
These are all over The Netherlands and widely used by animals.
0points
Here in Sweden, we have great success with wildlife bridges and more is being built, along with wildlife passageways (for when large animal end up on the road, there's a way out for them through the wildlife fences).
Studies: https://triekol.se/triekol-3-eng/over-and-underpasses-for-la...
PaulHoule
https://environmentamerica.org/articles/do-wildlife-crossing...
https://pmc.ncbi.nlm.nih.gov/articles/PMC9753749/
In my neighborhood (NY not VA) we had some people make a crossing for these guys this spring
https://www.virginiaherpetologicalsociety.com/amphibians/sal...
idiotsecant
There is one east of Seattle that gets used by wildlife quite a lot. When you're up there the interstate is very quiet due to all the earth between you and it, and they keep both sides of the crossing well wooded and obscured from view from the interstate. The animals figure out pretty quick where to cross.
poopsmithe
That one's cool because animals can cross over or under https://www.youtube.com/watch?v=Cf5nMLrlgW4
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komali2
Gigantic roads like that make me crazy! I can't understand how people subject themselves to living near these giant impassible rivers of concrete! Even a city road that's not a freeway - on a visit to sf I needed to walk across Harrison and then 6th street. 12 lanes to walk across, two lights to wait for! I felt like tearing my hair out.
At least they finally built a way for the animals to cross again. I can't imagine how long it would take to walk across that eco bridge thing.
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downvotetruth
> having required 26 million pounds of concrete
the height restriction alone should have been reason enough to go with a tunnel, but how could CA miss an opportunity for construction waste /s
jeremyjacob
I believe they chose a bridge to create a more uniform natural path across the freeway so that the animals will be more likely to utilize it. There’s already an overpass a half mile to the south that would allow a crossing over frontage roads but because it’s not obvious and wild enough, animals still cross on the freeway.
jmye
You’d think the right thing to do would be to pick the option wildlife is most likely to use, and that there was research and decision-making that went into that above and beyond “tons of concrete”.
Do you think that didn’t happen, that you’re significantly smarter about wildlife bridges than the folks who planned this one (who were, apparently, too dumb to ask a question you thought of sixty seconds after reading about the amount of concrete used), or just deeply into throwing shade, deserved or not, at CA at every half-imagined opportunity?
cruffle_duffle
Perhaps rephrase as “designed as an underpass”. These things already are funnels for prey. I doubt a lot of wildlife is going to feel comfortable going through a tunnel. Humans don’t like going through tunnels to cross highways…
Because I agree about the cost of these things. They should be designed to be inexpensive so we can put them everywhere (eg: i90 through cascades… there is only 1 of these and it’s on the east side of the pass).
It annoys me greatly how seemingly over engineered and expense these are. We put a huge fence that divides the entire mountain range. These bridges should be all over.
That being said I’m pretty sure a lot of research goes into designing a wildlife bridge that animals want to cross. I think there was a practical engineering YouTube video that covered it. Turns out each species has their own preferences and peculiarities when it comes to this sort of thing. So to counter my own argument… it does no good to build a ton of these if no animals will actually feel comfortable using them.
Maybe they should fund some kind of wildlife outreach program and give brochures and flyers to the local wildlife explaining how to use their new overpass…
api
This is not a bad thing, but my first thought was: anything but housing.
I live nearby and drive past it nearly every day. It’s been fascinating watching its construction. They’ve done a very good job not impacting traffic and only closed down the highway late at night for a week or two.