Why do animals cross the road? Some are just migrating. Others seek food or mates. But whatever the case, they aren’t likely to pay much attention to traffic — and that can mean disaster. Every year in the U.S., an estimated 350 million animals and more than 400 people die in animal-car crashes. And even crashes that don’t claim lives still cost an average of over $4,100, according to insurers — which all adds up to billions in annual damages. 
That’s why animal crossings have become so popular. These specialized over- or underpasses allow wild animals — from wolves and bears to moose, deer, elk, and even butterflies — to pass safely. They’re typically covered with vegetation and terrain to make them more attractive to animals and may be fenced and off-limits to humans. According to one study, animals are 146% more likely to use one than a random stretch of road. Another long-term investigation showed that crossings reduced accidents by greater than 80%  annually.

Animal Overpasses Save Bambis … and Benjamins

The design and engineering firm Dialog led the structural engineering and landscape architecture of the overpass, which was funded by Alberta’s provincial department of transportation and is now the first wildlife overpass in Canada constructed outside of a national park. It’s in an area where reported vehicle collisions with deer, elk, coyotes, and grizzly bears happen 69 times per year on average. “The very rough rule of thumb is for every collision that is recorded or every carcass that is seen on the side of the road, you can usually double that number,” says Dialog’s Neil Robson, the overpass project manager and lead designer.

Located between Calgary and Banff National Park, this stretch of the Canadian Rockies is sliced in two by the Trans-Canada Highway, one of the busiest roadways in the province. That’s had deadly consequences for the area’s abundant wildlife, as well as the tens of thousands of people who drive through it every day. But now, after years of mounting wildlife-vehicle collisions, the danger to animals and humans is being addressed with a stunning new wildlife overpass.

The Bow Valley Gap wildlife overpass is a roughly 200-foot-wide cap over a four-lane highway, topped with soil and forest-like plantings that creates a bridge almost indistinguishable from the forest on either side.

This stunning wildlife overpass helps animals cross one of Canada’s busiest highways 

How creating wildlife crossings can help reindeer, bears – and even crabs

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Sweden’s announcement this week that it is to build a series of animal bridges is the latest in global efforts to help wildlife navigate busy roads

Every April, Sweden’s main highway comes to a periodic standstill. Hundreds of reindeer overseen by indigenous Sami herders shuffle across the asphalt on the E4 as they begin their journey west to the mountains after a winter gorging on the lichen near the city of Umeå. As Sweden’s main arterial road has become busier, the crossings have become increasingly fractious, especially if authorities do not arrive in time to close the road. Sometimes drivers try to overtake the reindeer as they cross – spooking the animals and causing long traffic jams as their Sami owners battle to regain control.

“During difficult climate conditions, these lichen lands can be extra important for the reindeer,” says Per Sandström, a landscape ecologist at the Swedish University of Agricultural Sciences who works as an intermediary between the Sami and authorities to improve the crossings.

This week, Swedish authorities announced they would build up to a dozen “renoducts” (reindeer viaducts) to aid the crossings and allow reindeer herds to reach grazing more easily.

Ever wonder if animals really use those bridges to cross highways? They do! And not because they’re following signs.

Combining fencing with over- or underpasses together helps wildlife stay safe. That includes large species such as grizzly bears and elk and smaller ones, such as western toads and salamanders.

The fencing is an important part of these crossings, as it helps guide and funnel wildlife to the right spot and keeps them off the road.

The overpasses in Banff National Park are landscaped with soil, plants and trees to help them look like surrounding habitat. The underpasses are low and darker, providing the cover some species prefer.

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Vespula pensylvanica, the western yellowjacket, is a Nearctic species of wasp in the genus Vespula.[1][2] It is native to regions of North America, largely in areas with northern temperate climates. Its reproductive behavior is constrained by cold weather, which successfully reduces the number of western yellowjackets in cold months. However, in the absence of cold weather, this wasp's population can explode. The western yellowjacket has become particularly invasive in the Hawaiian Islands, resulting in their label as a major pest.[3][4]

Vespula squamosa, or the southern yellowjacket, is a social wasp. This species can be identified by its distinctive black and yellow patterning and orange queen.[1] This species is typically found in eastern North America, and its territory extends as far south as Central America.[1] Within these territories, they create enormous, multiple-comb nests.[2] The colonies may be either annual or perennial depending on the climate, and in many perennial nests, polygyny takes place.[3] In addition, this species uses pheromones both as a sexual attractant and an alarm signal.[4] This species feeds on insects and animal carcasses; it does not produce honey.[5] V. squamosa, a social insect, has developed a parasitic relationship with the species V. vidua and V. maculifrons.[2] Due to their painful, venomous stings, the species is considered a pest.[1]

Yellowjacket or yellow jacket is the common name in North America for predatory social wasps of the genera Vespula and Dolichovespula. Members of these genera are known simply as "wasps" in other English-speaking countries. Most of these are black and yellow like the eastern yellowjacket  (Vespula maculifrons) and the aerial yellowjacket (Dolichovespula arenaria); some are black and white like the bald-faced hornet  (Dolichovespula maculata). Some have an abdomen with a red background color instead of black. They can be identified by their distinctive markings, their occurrence only in colonies, and a characteristic, rapid, side-to-side flight pattern prior to landing. All females are capable of stinging. Yellowjackets are important predators of pest insects.[1]