because you never know when it's coming.

因為你永遠不知道牠什麼時候會出現。

By the time you do see it, it's often too late.

等你看到的時候，通常已經太遲了。

But what if there were crossings for animals, just like the ones used by humans?

但如果有像人行陸橋那樣專屬於動物的廊道會怎麼樣呢？

In some places, planners have built exactly that.

在某些地方，規劃人員的確建造了動物廊道。

And data shows that animals are using them,

而且資料也顯示，動物有在使用。

which means that close calls like this are far less likely to happen.

這表示像這種千鈞一髮的情況，就比較不會發生了。

Hitting an animal is a risk anywhere roads are built through animal habitats.

任何興建在動物棲息地的道路都有撞到動物的風險。

And as more roads are built, there are more opportunities for collisions.

而隨著道路越蓋越多，碰撞的機會也更多了。

According to a 2008 study commissioned by the US Congress, the number of animal-vehicle collisions was increasing.

據 2008 年美國國會一份委任研究指出，動物與汽車的碰撞事故持續增加中。

Experts blamed the rise on more vehicle miles traveled combined with a growing North American deer population.

專家將此歸咎於車輛行駛里程數的提升，還有北美鹿群數量的增加。

But the official tally excludes accidents that have less than $1,000 in property damage.

但官方統計排除了財產損失低於 1,000 美元的事故。

If you account for minor collisions, unreported accidents, and other variables,

如果你將小型碰撞、未回報事故，還有其他變數計入，

experts estimate at least one million collisions with large animals—meaning deer, elk, and moose—occur every year in the United States.

專家估計美國每年至少有 1 百萬件鹿隻、駝鹿和麋鹿等大型動物的碰撞事故。

And while animal-vehicle collisions rarely cost lives, they do cost money.

雖然動物與車輛碰撞很少使人類喪命，卻會造成財物損失。

In the US, wildlife-vehicle collisions cost over 8 billion dollars every year—

在美國，野生動物與車輛的相撞事件每年造成逾 80 億美元的損失。

money that is spent on vehicle repairs, medical costs, and other expenses.

花費主要都是在車輛修復、醫療費用及其它開銷。

And although humans tend to survive, animals often get killed.

而雖然幾乎沒有人類傷亡，但動物通常會死亡。

In the same report, researchers found that vehicular traffic threatened 21 endangered species, including the bighorn sheep.

在同一份報告中，研究人員發現車流威脅了 21 種瀕危物種，包括大角羊。

In some places, highway planners have solved the problem by building fences to keep animals off the road.

在一些地方，高速公路規劃者透過建造圍籬把動物與道路隔離開，以解決這個問題。

A relatively cheap solution that has been proven to reduce roadkill by over 50%.

這是個相對便宜的解決方法，數據也證明這個方法減少超過 50% 的路殺事件。

But although fencing reduces roadkill, it neglects a wider problem.

但儘管圍籬減少了路殺數量，卻疏忽了更大的問題。

Besides the risk of collision, roads harm animals by dividing wildlife populations and limiting their ability to find mates, food, and other necessities of life.

除了碰撞的風險，道路對動物造成傷害還有隔離野生動物族群，限制了牠們尋找配偶、食物與其它生活必需品的能力。

In Canada, wildlife scientist Tony Clevenger has been studying how road construction affects animals in Banff National Park.

加拿大野生動物科學家 Tony Clevenger 一直在研究班夫國家公園的道路建設如何影響動物。

It can have important impacts on the reproductive success

道路對於生殖成功率有很重大的影響。

because females aren't being able to access important spring habitat,

這歸因於雌性無法進入重要的春季棲息地，

because they are not crossing the highway.

因為牠們無法越過高速公路。

So, it's important that we maintain these movements and we maintain this access to the important biological resources throughout the year.

所以，常年維持動物的活動以及獲取重要生物資源的途徑非常重要。

And wildlife crossing structures do that.

而野生動物廊道的功能就在於此。

Beginning in the 1980s, authorities began installing a system of underpasses and overpasses in Banff.

自 1980 年代始，當局就開始在班夫國家公園設置地下道與陸橋系統。

The structures were designed for animal use only and were located where animals were likely to cross the road.

這些建築只供動物使用，並架設於動物最有可能跨越的道路上方。

The data speaks for itself, for example, here on the Trans-Canada Highway in Banff National Park,

數據會說話，舉例而言，班夫國家公園的加拿大橫貫公路在興建圍籬與野生動物廊道前，

there were, on average, more than a hundred elk-vehicle collisions per year before the fencing and the wildlife crossing structures,

平均每年發生逾百件麋鹿與車輛碰撞事故，

and now it's down to less than a half-dozen.

而現在已經降至六件以下。

So these are huge reductions, by having these mitigation measures in place that are improving motorist safety; they're saving lives."

這些緩解措施大量減少了事故，提升駕駛安全，拯救了性命。

And also, in a protected area like Banff National Park, it's important because the objective of this National Park is to protect wildlife.

而且在像班夫國家公園這種保護區中，這些建設很重要，因為國家公園的目的就是保護野生動物。

Instead of blocking the road entirely, planners used fences to funnel wildlife towards the crossing structures, which were planted with native vegetation.

與其將整條道路封起來，規劃者利用圍籬，將野生動物導向種滿了當地原生植物的廊道。

A few species, like deer, elk, and moose, immediately started using them.

有一些像鹿、駝鹿和麋鹿等物種馬上就開始使用廊道。

And were followed by more skeptical species, like wolves and grizzlies.

其餘像是狼與灰熊等較易疑心的物種也開始跟進。

Within a few decades, even the most reluctant species, like lynx, had adapted to using the crossings.

接下來數十年內，連山貓這種最不願意使用廊道的物種也習慣了使用動物廊道。

In 2012, a male grizzly was recorded crossing the structures 66 times in one summer.

2012 年，紀錄顯示一隻雄性灰熊整個夏天跨越廊道共計 66 次。

By crossing the highway, the bear's habitat expanded to include potential mates on the other side of the road,

藉由橫越高速公路，熊的棲息地擴展到可能有潛在配偶的公路另一端，

which decreases the likelihood of inbreeding.

減少近親繁殖的可能性。

What we've been able to show is that by having these overpasses and underpasses in place,

我們能夠展現的是，透過在適當的位置設置地下道與陸橋，

we've restored genetic connectivity across the highway here in Banff National Park.

我們恢復了班夫國家公園高速公路兩端的基因連結。

Wildlife crossing structures are fairly common in some parts of the world, particularly in Western European countries like the Netherlands.

野生動物廊道在世界某些地方相當普遍，尤其是像荷蘭這些西歐國家。

But there are relatively few in North America.

但北美就相對較少。

And the success of the Banff crossings has encouraged similar projects in the United States, like this rendering of an overpass being built in Washington State.

而班夫國家公園廊道的成功，也激勵了美國類似的專案，如效果圖所示，位於華盛頓州興建中的陸橋。

And in 2012, the Wyoming Department of Transportation built an overpass that reconnected an ancient migration route of the pronghorn antelope.

以及 2012 年，美國懷俄明州運輸部興建的陸橋，重新連接了叉角羚羊的古老遷徙路徑。

So, if these crossings are improving safety and restoring habitats, why aren't they everywhere?

那麼，如果這種廊道可以提高安全性並復育動物棲息地，為什麼仍然不普及？

Probably the biggest factor that would limit construction of wildlife crossings is cost

限制野生動物廊道建設的最大因素可能是成本，

and having the funding within the transportation agency budgets to build these wildlife crossing structures.

以及運輸當局是否有能夠興建這種野生動物廊道的預算。

Structures can save money in the long run, but the initial investment is significant.

這種建設長遠看來可以節省開銷，但初期所需的投資金額龐大。

Constructing an overpass like this one in Banff typically costs several millions of dollars.

建造像班夫公園這種陸橋通常需花費數百萬美元。

So to create more cost-effective solutions,

所以為了要建造更多句經濟效益的解決方案，

Clevenger organized a design competition with a group of experts that included ecologist Nina-Marie Lister.

Clevenger 和一群包括生態學家 Nina-Marie Lister 的專家一起規劃了設計競賽。

They named it ARC, short for "animal road crossing".

他們稱之為 ARC（動物道路通道）。

Our argument was, for the money that was spent, you could be getting a lot more value,

我們的論點是，如果是專為目標客戶，

if you designed them specifically for the target client, which is wildlife and humans driving underneath them.

也就是野生動物和開車通行的人類設計，同樣的花費可以獲得更高的價值。

Instead of adapting traditional plans from highway engineers,

與其改造高速公路工程師的傳統藍圖，

ARC encouraged different stakeholders to collaborate on structure design.

ARC 鼓勵不同利害關係人在建築設計上合作。

There had to be a landscape architect, an architect, and an engineer, as well as ecologist.

團隊必須要有景觀建築師、建築師、工程師，以及生態學家。

And so for the first time ever,

於是，史無前例地，

you had a very different way of designing a structure and we asked for them to be ecologically sustainable.

出現了非常不同的設計方式，而我們也要求其生態永續性。

They also had to consider materials that were recyclable, reusable, modular, and moveable.

他們也必須考慮可回收、可再利用、可模塊化，以及可移動的材料。

The contest was a success and ARC generated groundbreaking solutions,

競賽非常成功，ARC 也產出了許多開創性的解決方案，

including a winning design that reduced costs and improved safety by removing the need for pillars on the highway.

其中獲勝的設計透過移除高速公路上墩柱的需求降低成本並提升安全性。

The cost of that overpass was about 30 to 35% cheaper than overpasses that were being built at the same time in Banff National Park.

該陸橋的花費約比班夫公園同期建造的陸橋少了約 30-35%。

The state of Colorado agreed to build the design, but more immediate needs, including a flooding event in 2013, have prevented development.

科羅拉多州同意搭建該設計，但包括 2013 年淹水等更迫切的需求阻礙了工程。

You can see entire roads washed out.

各位可以看到道路被完全沖毀。

The design was never built, but that doesn't mean it won't be.

該設計從未被搭建，但那不代表它不會發生。

As climate change strains ecosystems and reduces habitats,

由於氣候變遷損害生態系統並減少生態棲息地，

animals will change their patterns of movement and the need for effective crossings will become even more acute.

動物會改變牠們的行為模式，而對於有效的廊道需求將變得更為迫切。

To solve the problem, Lister hopes that planners will return to the ARC designs, which remain viable solutions.

為了解決問題，Lister 希望規劃人員重新採納 ARC 仍為可行解決方案的設計。

These things work and they solve the problem once and for all.

這些東西是能夠奏效的，而且它們也可以一次性地解決問題。

So, if you build a network of these bridges that connect in the right places, you've solved the problem for good.

所以說，如果你建構一個廊道網絡，在對的地方連結，就可以永久地解決問題。

It's done. Problem solved.

大功告成，問題解決。