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.
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.
One of my favorite wildlife stats is that you're hundreds of times more likely to be killed by a deer than a mountain lion. Protecting apex predators like wolves and lions significantly reduces deer caused deaths and injuries. It's nice to see public opinion steadily changing in this area for the better, past predator management has been extremely stupid and harmful.
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.
I wonder why they didn't opt for your suggestion for multiple modest projects.
The article doesn't mention it, it only says:
> National Park Service began a decades-long study of the region’s mountain lion population that the 101 freeway was deemed “the most significant barrier to the ecological health of the region.”
> NEPA Completed 04/12/2018: Finding of No Significant Impact (FONSI), Liberty Canyon Wildlife Habitat Connectivity Project
> In compliance with CEQA, Caltrans held a 47-day public scoping period to allow the public and regulatory agencies an opportunity to comment on the scope of the IS/EA and to identify issues that should be addressed in the environmental document. A scoping report documents the issues and concerns expressed during the public scoping meetings held on January 14, 2016 and the written comments received from the public, community organizations, and governmental agencies during the public scoping period from December 14, 2015 through January 29, 2016. The release of the Final Environmental Document with responses to comments included was completed in the summer of 2016. NEPA/CEQA was completed in April 2018. A total of 8,859 comments were received in response to the draft Environmental Document, with only 15 opposed.
When any infrastructure project requires nearly a decade of preliminary work before shovels hit ground, said work becomes impossible to accomplish for smaller-scale builds. Even if ten smaller bridges would be a better solution, 10x-ing the review process would likely be impossible at current staffing / budget levels.
If it's too small/unsafe you'll end up with wildlife not using it or being funneled in for other for predators. The larger and more skittish the animals you want to use it, the larger you're going to want to make it. Since they're calling out mountain lions, which are quite skittish, they're going to need a large (and probably partially covered) pathway for them to want to use it--as opposed to treating the freeway like the barrier it is to wildlife.
I'm sure there's more to it than that, but making it desirable, accessible, and for it to feel safe for the target animal population is important for it to accomplish what it's intended to do.
There are smaller culverts all over the place for smaller wildlife. I've even seen some called out in small walking paths--there for the frogs and other amphibians.
That’s truly an unbelievable amount. I suppose there is some breakdown of this available. Would love to hear from someone who knows on the actual reasonableness of the costs. Seems exceptionally out of line from the sidelines.
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 )
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
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.
However you slice it, the time it took for this project to complete is absurd. Project started in 2002, it took 20 years to plan this, then it took 3 years to build this low-tech bridge.
Even without looking at China and Middle East - in Texas they build entire highway intersection in a year.
This bridge is not low tech. It utilizes a number of construction techniques and materials that weren't avaliable in 2002. It also spans a major freeway. It was never going to be cheap.
in Texas they build entire highway intersection in a year
California can and has rebuilt bridges in a weekend. And based on the TX Dept of Transportation website, construction on the Dallas High Five took 4 years from start to finish, after a decade of planning. And cost more than this bridge despite requiring less infrastructure to be constructed.
Morbidly curious, I'd love to see a full cost and time breakdown of these projects to understand exactly where the $100M and 3 years goes. How much of that is actual people wearing boots and hardhats, and how much of it is paperwork, and waiting for this inspector to inspect that thing and then unblock this other bureaucrat to stamp onto that other paper. I'd bet the actual amount of time and money spent actually building was a single digit percentage vs. the amount of time and money spent on process and paperwork and waiting for clerks to go through their 1,000 item backlog of forms to fill out and stamp.
This is an interesting point, but I wish the delivery wasn't so snarky. There probably are a number of issue of specialization that I wonder about now; is building bridges in an earthquake zone a solved problem at this point, or does it require additional focus that could justify some of the time and money cost. Similarly, desert ground can move a surprisingly large amount through heat and rain cycles; are similar challenges faced in places like Arizona and Texas for more ground-based infrastructure?
A bridge for deer isn't any easier to build than a bridge for pedestrians, even if you don't care about deer being on a bridge that collapses there's a highway underneath. Cars would be crushed and traffic disrupted. So we're just talking about a bridge. It's built to the same standard as any other bridge. (Also it's more like a bridge for mountain lions but whatever.)
If the Empire State Building had been built across a highway, and had to schedule construction around avoiding disruptions to traffic, than it would've taken three years too.
Typical pedestrian bridges aren't 150 feet wide, though. Nor do most have grass growing on them (at least, not intentionally). This is, in fact, a fairly unusual infrastructure project.
Pedestrians also happen to be much denser than cars though, since cars are mostly air, while humans are mostly water, which can lead to some interesting situations (and Wikipedia articles)
My dad worked for a while as an accident investigator for the Air Force. One time there was a crash where a pilot deliberately flew into a cliff at top speed.
The only evidence they ever found of his body was a finger joint. My dad said the body just turns into spray at those speeds.
We went faster when human life had less value. It has more value now, both in labor time (and therefore cost) and harm potential/reduction, so it takes more time and money than it used to. Similar story about disposable workers when the Hoover Dam was built.
We should expect this math to continue as prime working age cohort shrinks over the next century due to structural demographics.
For deer? It's much more for the endangered wild life like mountain lions. I loved in so cal and we had multiple passes like this and it was incredibly helpful in maintaining the mountain lion population
Weird how you're downvoted. IMHO, it should not stop its construction, but it's an interesting question. Undoubtedly, after dumping soil on the bridge, shrubbery and even trees will grow, so yes, it could act as a wildfire bridge.
Note that the article also says it offers an escape route from wildfires, so it goes both ways.
If had to guess about the downvotes: the note about the article you point out (that's the big reason), plus (and this was just the first thing of a handful of relevant information) the easy answers with a quick search https://valleynewsgroup.com/wildlife-bridge-wont-become-a-wi...
Which took less typing to find than making the comment.
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.
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?
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).
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.
There are also fences along the freeway for what seems like miles. That's to funnel the animals to the crossing. There are also 10 or so under crossings drivers can't see.
Yep these bridges have been researched and found to be quite effective. It sounds like this bridge was unusually expensive but on average they even work out to be neutral or +EV on cost due to all of the prevented accidents.
There is a wildlife bridge like this in orange county where I used to live and it was very often used, it is directly responsible for increases in their numbers
I wonder if there are any plans to place meat along the bridge to attract mountain lions. Will ecologists try to "train" the wildlife to use the bridge, or just let nature take its course?
The hardest part might be getting them to wake up early enough for the ribbon cutting. I saw America perform at the Ventura County Fair around noon, and they complained it was the earliest gig they had all year. But it was Ventura Highway in the sunshine, which was its own kind of awesome.
Huh, why does the embedded video look like someone played it over a Zoom screen-sharing session, and another participant of that Zoom meeting did a screen record?
There's a lot of people in this forum that greatly underestimate how hard and expensive it is to build things in the real world when you need to get things right the first time (because it can't just patch it later).
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).
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.
The first sentence is almost completely subjective, and the leading fact in second sentence gives the best evidence against an overpass in this thread. The only thing that is going to make this more obvious to the mountain lions would be a few more dead deer carcasses as a result of the car lights! lets jump off the side into oncoming hidden traffic behavior.
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?
No, I do think that happened and that the underpass was the more reasonable solution; why Caltrans required due to the bridge’s size and cost to have its completion be reliant on donations from the public.
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…
> 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…
For the Snoqualmie bridge, (some of) the local wildlife trespassed to use it before it opened, so I'm not sure if they need to do much outreach.
I think the better projects include post construction observation and reasonable minor modifications to help encourage use; typically adjustments to fencing or maybe some earth works.
I already saw that video and my comment reflects what he states that underpasses usually cheaper than overpasses like this (9:10); given that fact more (culverts - 9:30) could be built for the more numerous non-apex species that do not lend well to being diverted miles to such a monstrosity. Of the listed species expected to benefit from this crossing including bobcats, coyotes, gray foxes, birds of prey, skunks, rodents, American badgers, American black bears, fence lizards and mule deer only the mule deer have may be having herding behavior causing carelessness to not use such an underpass.
Cutting and covering a few lanes at a time would not have cost $92 million. Even better, a horizontal drill would have less chance of lane closures than the bridge option.
It's something the locals have known was needed for a long time, I'm glad they were finally able to get it built.
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