Forested Overpasses Allow Animals to Cross Safely Over Highways | Hacker News Reader

Forested Overpasses Allow Animals to Cross Safely Over Highways

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134 pointsvinnyglennon71 comments

Um, has anyone taken a look at the other stories on this domain?

http://www.ewao.com/a/1-scientists-prove-our-dna-has-telepat... http://www.ewao.com/a/1-11-reasons-why-the-hollow-earth-actu...

I took our kids to find one of these ("ecoducts" in the Netherlands) about a half hour drive from where we live. It was fantastic: no sign of humans anywhere except the speeding traffic under us on the motorway; just lots of animal footprints, and a single surveillance camera that I imagine is used to check out the furry users of the bridge rather than for any "security" related tasks.

The kids loved it :) They found it pretty spooky though.

It's very weird standing on what feels like a big hill with grass, sand and trees, knowing the motorway is rushing by under your feet.

I bet that's the same experience some people have with an aqueduct - https://upload.wikimedia.org/wikipedia/commons/d/d8/Ie-akwad...

Forested overpasses are expensive, and so few will ever be built.

A simple, cheap, and unglamorous solution is to simply put culverts under the highway at regular intervals, open at both ends. Culverts come ready made in all sorts of sizes, just dig a trench cross-ways and drop it in during construction or repaving.

Highways tend to be above grade anyway, so the openings of the culvert can be above grade and it won't fill with water.

Of course, this does not preclude having a fancy forested overpass here and there as well.

I still remember when these overpasses were first built, there was a lot of scepticism and animals were initially wary to cross. However it's nice to see how much of a success it's become.

Not too long ago I took the wife's family to Banff, we checked out one of the information buildings, they showed a time-lapse video of the various animals that cross (pretty much every type of large mammal in the park). Was very interesting and nice to see.

If I am a meat eating animal like a wolf or something, Do I just have to wait at this bridge to hunt?

I have a vision, inspired by this problem, where every major highway is a "forested overpass".

Instead of bisecting the top layer with roads and fences, build all major roads in tunnels, and bring the recovered surface area back to it's original state for all to enjoy.

Availability of suitable habitat for native species is only getting worse. If we blindly follow the path we are on, confrontation and compromise are inevitable, and humans don't typically lose this battle.

It's no surprise city centers and golf courses occupy the most desirable land (valleys along waterways). Southern California especially has a habit of teraforming natural waterways and fencing them to prevent access; it's amazing any water is still available to wild animals.

Someone proposes a cost effective solution then someone else feels the need to take the solution to a limit. "Just put everything underground"

How about we try the cheaper solution first then talk about burying highways at a later date?

Even if we were ignoring cost and reality completely, I'd prefer we just buy everyone an autonomous helicopter before we bury all roads.

>build all major roads in tunnels, and bring the recovered surface area back to it's original state for all to enjoy.

How deeply have you thought this idea through? What happens in places like Florida where the water table is so high you can't dig deeper than a few feet? How do you manage entrances and exits, how do you make sure there's breathable air down there in case people have to get out of their cars? How do you vent poisonous gases? How do you keep the precious animals you're trying to save from getting in there and getting trapped or run over? What about emergency access? You can't open a gate on a service road and suddenly be underground.

Those are just a couple of simple practical considerations that don't even factor in cost, which would be prohibitive.

These are all problems that have been solved. There are many existing solutions for elevating people...

Are you suggesting that it is impossible to build a subway where groundwater exists? [1]

All sizable tunnels have ventilation. While we still run combustion engines, we could capture unburnt fuel vapor and use it. With electric vehicles the capacities needed are much lower.

> How do you keep the precious animals you're trying to save from getting in there and getting trapped or run over?

Animals will not have a reason to enter if there is not something to be gained. Currently, they are provoked by the need for water and food, which justify the dangerous risks they must take. Living every day as a gatherer with no guaranteed access to water is not something I'm not convinced you have the empathy to understand.

[1] http://scienceline.org/2010/02/what-would-you-do-with-eight-...

"Are you suggesting that it is impossible to ..."

No, merely expensive. The Gotthard Base Tunnel is US$10.3 billion for "a route length of 57 km (35.4 mi) and a total of 151.84 km (94.3 mi) of tunnels, shafts and passages". (Quoting Wikipedia.) That's $290 million/mile.

The Fehmarn Belt Fixed Link is estimate to cost €4.7 billion for 17.6 km of immersed tunnel, or $480 million/mile.

The boondoggle that is the Alaskan Way Viaduct replacement tunnel is in the same range.

By comparison, a rural interstate road costs about $5 million/mile, or a factor of 50 cheaper.

Your points are all valid. I want to add that the equivalent for a tunnel for parts of Florida is an elevated roadway. When State Road 84 was built through the Everglades, it blocked water flow and generally had poor environmental planning. The upgrade to I-75 included 'bridges and culverts designed to let water and wildlife pass underneath' (quoting Wikipedia).

Eventually, better materials and robotic construction is going to be very cheap and roads will move under ground. Or these overpasses will be built.

Or robotic vehicles will all slow down as animals approach a highway, while other smaller robots (maybe drones) herd them across with sound effects.

One way or another, this problem will be solved. How all these technologies will evolve and which ones will solve it first is anybody's guess.

In Grand County, Colorado, where I live, there happens to be a project to build just such an overpass happening right now:

https://www.codot.gov/projects/sh9wildlife

http://denver.cbslocal.com/2015/09/21/cdot-wildlife-overpass...

This stretch of highway is so populated with wildlife that we would often see a handful of new unfortunate strikes every morning, and most everyone around had a story of a near miss or a hit. Underpasses and overpasses are being utilized and a fence runs along both sides to funnel the animals to them.

A fence was put in place along I-70 near us and has been rather effective but there are no underpasses and no overpasses in that implementation. In our area, the wildlife need to travel to the Blue River on one side of the highway for water and back up the mountains on the other side of the highway to graze (and give birth, etc.)

Money was raised not only from government sources but from a local resident pledge drive as well as a very gracious benefactor who owns land in the affected area.

People in cities need something similar. It would be hugely beneficial to have a bustling business district lined up on the left and right side of urban freeway crossings.

Atlanta has started doing that by greatly widening bridges over the Downtown Connector, so they include parks. Example: https://www.google.com/maps/@33.7768753,-84.3909918,3a,75y,4...

I wonder if that's partly thinking forward to a possible street widening?

This particular example basically connects Georgia Tech's campus across the highway, There was no plan on expanding the road. The lawns actually get a lot of use, students studying/lounging during the week and popular for tailgating on Saturdays.

This is the entire point of projects to put freeways in tunnels.

I run into this in Barcelona: https://goo.gl/maps/4fQfpa7CoPH2

On the other hand, look at something like the Cross Bronx Expressway.

https://goo.gl/maps/RfeVWuS2X5J2

A neighborhood torn apart 60 years ago....is still torn apart.

Do you know if the residential/commercial developments around the tunnel were built at the same time as the roadway? New transportation infrastructure is much easier to integrate into new urban developments, but it would be nice to see something done in existing communities.

Perhaps in the future it will be less expensive to drill tunnels! Looking at how rapidly automation is advancing, it is highly likely.

But due to the currently high cost of construction projects, there is a lot of infrastructure that must be augmented rather than replaced.

The I-670 cap in Columbus, OH is a good example. https://commons.wikimedia.org/wiki/File:Cap_at_Union_Station...

Baltimore has an interesting network of outdoor walkways above street level connecting the inner harbor, convention center, and a few nearby buildings. I have long thought a city could do this for a much larger part of downtown at reasonable expense.

Crystal city VA on the other hand has an underground mall covering well over a mile including a subway stop. The upside is weather becomes irrelevant, but the downside it's a winding path making the surface faster and presumably it costs much more to build and maintain.

I'll have to check those out when I go to the area in the future.

In SF there are a few spots where active use occurs underneath freeways. Also, in Taipei I saw a huge marketplace for jade and for flowers underneath freeways.

Freeways cause so many ill social and economic effects on neighborhoods, billions are wasted every year in the big cities on dead space. There should be a huge investment toward restoring the urban fabric and bringing out the full value of neighborhoods around these structures.

Minneapolis does this: https://en.wikipedia.org/wiki/Minneapolis_Skyway_System

I was there in early fall, when it wasn't cold enough to make a difference, but we went through them for the novelty. Every time we emerged on the street, we were terribly disoriented.

Something like this (or rather, the reverse) was Walt Disney's plan for the Experimental Prototype Community of Tomorrow he envisioned: https://youtu.be/UEm-09B0px8?t=15m29s

Several cities in the colder parts of the US and Canada have extensive networks of enclosed pedestrian bridges, such that you could cross downtown without ever going outside.

For example, see Minneapolis https://en.wikipedia.org/wiki/Minneapolis_Skyway_System

They kinda did this in Boston and it was expensive but fantastic.

We do. Big highways without enough pedestrian bridges have a horrible effect on pedestrians and bikes, basically cutting towns and cities in half. I currently work just north of a 6-lane toll road, and it's a reasonable bike commute. I used to work just south of it, and it was a much worse commute, because there are no pedestrian bridges or small quiet roads crossing it, only a few busy arterial roads, full of drivers already in highway mode, trying to dive for an exit ramp, not thinking about pedestrians or bikes.

Wondering how/if they ensure the animals use the bridge rather cross the highway? Fencing? Natural selection (Animals who prefer bridges more likely to pass their genes down)?

the ones i have seen have fencing funnels to them, there are gates for humans to cross, but the fence runs from one overpass to the next. the animals have no choice but to use the overpass.

These should be mandatory for any new road construction through existing habitats.

Even driving on California's central coast (pretty populated area), you see a lot of roadkill like deer, foxes, bobcats, etc. Very sad and I'm sure not helpful to recovery of some of the species.

In Australia, we have a similar bridge but on a much simpler scale - a rope bridge that spans the Hume highway (for animals that need a continuous bridge). For our native animals that glide (but can't fly), poles spaced 30m or so accomplish the same goal.

http://theconversation.com/mysterious-poles-make-road-crossi...

How about New Zealand?

IIRC I heard that some kiwis actively encourage drivers to run over anything that ventures onto the road, since any medium-sized animal that doesn't have wings is an invasive species in New Zealand. Not sure if it was a joke.

You see a similar idea quite often on the north shore of the St. Lawrence in Quebec. Usually they are underpasses, though, and usually combined with a 8-10', very sturdy fence system to funnel the animals into these crossing points and prevent them crossing the highway. Honestly, I think they are more motivated by preventing human fatalities from moose-vehicle collisions, which are exceptionally deadly, primarily, with the ecological concerns secondary.

Since a riverside highway is usually several meters above the water level, an underpass offers direct access to water. An overpass, on the other hand, would need to come down steeply on the other side, which is not only inconvenient but also very ugly.

But I've heard that some species don't like to go through tunnels, because predators might lurk in the dark corners (or something like that). So the architecture will have to adapt to the species it is designed for.

I'm curious how they are engineering these overpasses to not be slowly torn apart by tree roots, if they even consider that at all.

That's going to happen no matter what. All you can really do is design them to be big and sturdy enough to last roughly as long as the road system. It doesn't make sense to try and severely outlive the roads that they cross.

Well the ones in the video actually had the road elevated rather than have a wooded overpass... it seems like that makes more sense longterm.

I think this is more a question of planting trees with roots that don't go too deep.

But, even if not - rebuilding them every 15 years might be cheaper than sound engineering for this problem space. After all, they don't have to handle 40 ton trucks or 50 cars at a time.

Agreed, but if you REALLY wanted to be sure, you could always put a large sheet of aluminum just above the bottom layer.

I thought there were problems with aluminum and plants.

It isn't that bad of a problem. Green roofs are becoming very common. It is just about the depth of the soil, the selection of the correct plants and usually some type of plastic barrier.

From that viewpoint, the difference between this and a tunnel is minute.

They may be built the other way around, but you _can_ see these things as artificial hills with a tunnel dug through them. The effect of tree growth on their longevity will be similar.

In Germany "Grünbrücken", as they are called, are actually quite common. We have over 70 of them (as of June 2014).

It is part of the EU regulations to have them in Europe when you build or modernize highways. This is to prevent the isolated islands for animals (at the moment Belgium is the most fractured land in EU).

In France, I even spotted one for bats! http://france3-regions.francetvinfo.fr/rhone-alpes/2012/11/2...

We have these in Montana, at least on the Flathead Indian Reservation where I lived until recently. It's a great idea and really helps preventable deaths to elk herds.

Here's a picture (note: the language on that sign is Salish) http://www.sunnyskyz.com/uploads/2015/01/mpr6e-animal-crossi...

Cool. I cannot help but think it would be majorly uncool if the elk decide to fight on it and come down on my car. I passed within 3 ft of an elk on a slippery road during a blizzard in the 90's. Those things are scary dangerous.

Here's one that's been up for years on Hwy69 just south of Sudbury, Ontario, Canada: http://www.sudburyelk.ca/index.php?option=com_content&view=a...

It'll be on the order of $40 million for a big one in Los Angeles (Agoura):

http://www.latimes.com/local/lanow/la-me-ln-caltrans-propose...

You'd think it would be cheaper just to breed more animals.

1. Never heard of this website

2. Labeled as news, but not news

3. Every ~10th word is an erroneous concatenation of two normal words, like "effecton" or "animalslike"

Conclusion: this is … some sort automated content piracy website?

We already have a lot of those in the Netherlands. This is a step in the right direction. Ideally, I would like to see highways surfacing here and there between forests instead of the other way around. I think this is the direction we are heading in though. We are now at a point in time where we can afford to invest in beautifying our environment instead of just manipulating it to suit our needs.

This site is frustrating on mobile. Every time I touch the screen to scroll the page, a menu that I don't want slides in to cover the article.

Perhaps not a better website for mobile, but I'm pretty sure the pictured crossings are from Banff national park in Alberta and probably more going into BC. You can see pictures and find more information here:

http://www.pc.gc.ca/eng/pn-np/ab/banff/plan/transport/tch-rt...

The one drawback is that in order to get the animals to go over the overpass, you need to block them from just crossing the road. Some of the highway near Banff has a continuous chain link fence along the roadway. It kind of ruins the view.

These seem very similar to the "lids" that are put over freeways in affluent areas around Seattle. They're basically parks; there's little wildlife in urban regions.

I am suddenly reminded of this:

https://www.youtube.com/watch?v=Avo0-8GvBlA

Unfortunately in the US in many places we can't even get adequate paving, so expecting animal overpasses is a bit of a stretch.

Very cool. Hopefully other geographies adopt this idea. Also, on a separate note, looks like the site was built with Meteor.

I've read a lot about these, as I often drive under one in Montana. They are a tremendous success!

I wonder how these will affect the predator/prey balance.

Indeed. Predators can just camp out on the bridge waiting waiting for prey. No idea what that means in the bigger picture of balance.

If we can't get humans to use crosswalks, how can we expect animals to use these?

What a colossal waste of resources.

What makes you say that? In the case of the I-90 project in the linked video, they addressed issues of risk and cost, as well as proof of use by animals, in the planning stage.

i wonder on a grand scheme of things if this is really a waste/spend of resources that actually matters.

if people in 200 years from now look at our century's (or even generation) expenses - would they even see those kind of expenses anywhere?

on the flip side:

balance in nature is something we have still a very hard time recreating. reversing extinction is close to impossible. and imbalance of nature is potentially one of the biggest cost drivers for future generations.

i see this as cheap R&D for future investments in the balance of nature 100 years from now.

The problem is that Canada chose to route their largest national highway, Trans-Canada Highway 1, right through a National Park. This is just mitigating the downsides of that decision.

I'm thinking the national park came after the roadway? Or at least the railroad?

It's not like someone said "Hey, that's a nice national park, let's run a road right through it."

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