In addition to conservation concerns, wildlife-vehicle collisions have a significant cost to human populations because they damage property and injure and kill motorists. Bruinderink and Hazebroek (1996) & Hazebroek (1996) estimated the number of collisions with ungulates in Europe at 507,000 per year, resulting in 300 people killed, 30,000 injured, and property damage exceeding $1 billion.[3]​ In parallel, 1.5 million traffic accidents involving deer in the United States cause an estimated $1.1 billion in vehicle damage each year (Donaldson 2005").[3]​.

The conservation issues associated with roads (wildlife mortality and habitat fragmentation) coupled with the substantial human and economic costs resulting from wildlife-vehicle collisions have caused scientists, engineers, and transportation authorities to consider a number of mitigation tools to reduce conflict between roads and wildlife. Of the options currently available, structures known as Wildlife Passes have been the most successful in reducing both habitat fragmentation and wildlife-vehicle collisions caused by roads (Knapp et al., 2004, Clevenger, 2006).

Wildlife Passages are structural passages under or over roads, which are designed to facilitate the safe movement of wildlife crossing roads (Donaldson, 2005). In recent years, conservation biologists and wildlife managers have promoted wildlife crossings, coupled with roadside fencing, as a way to increase road permeability and habitat connectivity while reducing wildlife-vehicle collisions. The term “wildlife passages” is an umbrella concept that encompasses road underpasses, overpasses, ecoducts, green bridges, tunnels for amphibians and small mammals, and wildlife viaducts (Bank et al. 2002) as well as cable or rope runs for arboreal mammals. All of these structures are designed to provide semi-natural corridors above and below roads so that animals can safely cross without endangering themselves and motorists.

The first wildlife crossings were built in France during the 1950s (Chilson, 2003). [5]

The Humane Society of the United States reports that the more than 600 tunnels installed under major and minor highways in the Netherlands have helped substantially increase population levels of the European badger,[5]​ an endangered species. The longest "ecoduct", near Crailo&action=edit&redlink=1 "Crailo (Huizen) (not yet drafted)") in the Netherlands, runs 800 m and covers a road, a railway and a golf course.

Wildlife passes are becoming increasingly common in Canada and the United States. Recognizable wildlife passes are found in Banff National Park in Alberta, where vegetated overpasses provide safe passage over the Trans-Canada Highway for bears, elk, deer, wolves, and many other species (Clevenger 2007). The 24 wildlife crossings in Banff were built as part of a highway improvement project in 1978 (Clevenger 2007). In the United States, thousands of wildlife crossings have been built over the past 30 years, including drainages, bridges, and overpasses. These have been used to protect mountain goats in Montana, Ambystoma maculatum in Massachusetts, bighorn sheep in Colorado, desert tortoises in California, and endangered Florida panthers in Florida (Chilson 2003).

The benefits derived from constructing wildlife crossings to extend migration corridors for wildlife above and below major roads appear to outweigh the costs of construction and maintenance. One study estimates that adding wildlife crossings to a highway project represents a 7-8% increase in the total cost of the project (Bank et al. 2002[6]​). Theoretically, the monetary costs associated with constructing and maintaining wildlife crossings in ecologically important areas are less than the benefits associated with protecting wildlife populations, reducing vehicle damage, and saving the lives of motorists by reducing the number of wildlife-vehicle collisions.

A study completed for the Virginia Department of Transportation estimated that wildlife crossings become cost-effective, in terms of property damage, when they prevent between 2.6 and 9.2 collisions with deer per year, depending on the cost of the wildlife crossing. Approximately 300 deer crossed through wildlife crossings in the year the study was conducted (Donaldson 2005).

Contenido

Un número de estudios ha sido conducido para determinar la efectividad de los Pasos de fauna en proporcionar conectividad de hábitat (al proveer corredores de migración viables) y reduciendo las Colisiones fauna-vehículos. La efectividad de estas estructuras parece estar muy relacionada con los sitios específicos (debido a las diferencias en ubicación, estructura, especie, hábitat, etc.) pero los cruces han sido beneficiosos a un número de especies en una variedad de ubicaciones. Las historias de éxito de Pasos de fauna incluyen:.

Banff National Park

Banff National Park offers one of the best opportunities to study the effectiveness of Wildlife Passes as it contains a wide variety of species and is separated in two by a large commercial highway called the Trans-Canada Highway (TCH). To reduce the effects of the four-lane THC, 24 wildlife passes (22 underpasses and two overpasses) were constructed to ensure habitat connectivity and protect motorists (Clevenger 2007). In 1996, Parks Canada (that country's national parks agency) developed a contract with university researchers to evaluate the effectiveness of crossings. The first decade of the 21st century produced several publications analyzing the impacts of wildlife crossings on various species as well as on overall wildlife mortality.

Using a variety of techniques to monitor the passes since their creation, scientists report that 10 species of large mammals (including deer, deer, black bear, grizzly bear, mountain lion, wolf, moose, and coyote) have used the 24 passes in Banff a total of 84,000 times as of January 2007 (Clevenger 2007). The research also identified a "learning curve" showing that animals need time to acclimatise to using Wildlife Passages. For example, grizzly bear crossings increased from seven in 1996 to more than 100 in 2006, even though the actual number of individual bears using the structures remained constant during this time, at between two and four bears (Parks Canada, unpublished results). A similar set of observations was obtained for wolves, with crossings increasing from two to approximately 140 over the same 10-year period. However, in this case the actual number of wolves, in the packs using the crossings, increased dramatically, from a low point of two to a high point of more than 20 individuals. In line with these results Clevenger et al. (2001) reported that the use of wildlife crossings and fencing reduced traffic-induced mortality of large ungulates on the TCH by more than 80 percent. However recent analysis for carnivores showed that the results were not as positive for this other group, with bear mortality increasing on average 116 percent in direct parallel to the increase in highway traffic volumes, clearly showing that fencing had no effect in reducing bear mortality (Hallstrom, Clevenger, Maher and Whittington, in prep). Investigations of passes in Banff have shown a mixed value for wildlife passes, depending on the species in question.

Parks Canada is currently planning to build 17 additional crossings along the TCH to increase motorist safety near the town of Lake Louise. The lack of effectiveness of standard fencing in reducing bear mortality demonstrates that additional measures, such as T-fences, may be necessary to effectively mitigate for bears (Hallstrom, Clevenger, Maher, and Whittington, in prep).

In 2010, ARC Solutions – an interdisciplinary partnership – initiated the International Wildlife Crossing Infrastructure Design Competition for a wildlife crossing on Interstate 70 (I-70) near Denver, Colorado. I-70 is known as the "Berlin Wall" for Colorado wildlife and designers had to take into account many challenges unique to the area, including snow and severe weather, high elevation and steep grades, a six-lane highway, a bike path and high traffic volumes, as well as multiple species of wildlife, including bobcats.[8]​.

After receiving 36 proposals from nine countries, a jury of internationally acclaimed experts in the disciplines of landscape architecture, engineering, architecture, ecology and transportation selected five finalists in November 2010 to develop their conceptual designs for a wildlife passage structure.[9] In January 2011, the team led by HNTB with Michael Van Valkenburgh and associates (New York) was selected as the winner.[10] The design features a single span of 100 m (328 ft) concrete across the road, which is planted with a variety of vegetation types, including a pine forest and prairie grasses, to attract different species to cross. A pre-cast modular design means that much of the bridge can be built off-site and moved into place.[11]​.

In addition to conservation concerns, wildlife-vehicle collisions have a significant cost to human populations because they damage property and injure and kill motorists. Bruinderink and Hazebroek (1996) & Hazebroek (1996) estimated the number of collisions with ungulates in Europe at 507,000 per year, resulting in 300 people killed, 30,000 injured, and property damage exceeding $1 billion.[3]​ In parallel, 1.5 million traffic accidents involving deer in the United States cause an estimated $1.1 billion in vehicle damage each year (Donaldson 2005").[3]​.

The conservation issues associated with roads (wildlife mortality and habitat fragmentation) coupled with the substantial human and economic costs resulting from wildlife-vehicle collisions have caused scientists, engineers, and transportation authorities to consider a number of mitigation tools to reduce conflict between roads and wildlife. Of the options currently available, structures known as Wildlife Passes have been the most successful in reducing both habitat fragmentation and wildlife-vehicle collisions caused by roads (Knapp et al., 2004, Clevenger, 2006).

Wildlife Passages are structural passages under or over roads, which are designed to facilitate the safe movement of wildlife crossing roads (Donaldson, 2005). In recent years, conservation biologists and wildlife managers have promoted wildlife crossings, coupled with roadside fencing, as a way to increase road permeability and habitat connectivity while reducing wildlife-vehicle collisions. The term “wildlife passages” is an umbrella concept that encompasses road underpasses, overpasses, ecoducts, green bridges, tunnels for amphibians and small mammals, and wildlife viaducts (Bank et al. 2002) as well as cable or rope runs for arboreal mammals. All of these structures are designed to provide semi-natural corridors above and below roads so that animals can safely cross without endangering themselves and motorists.

The first wildlife crossings were built in France during the 1950s (Chilson, 2003). [5]

The Humane Society of the United States reports that the more than 600 tunnels installed under major and minor highways in the Netherlands have helped substantially increase population levels of the European badger,[5]​ an endangered species. The longest "ecoduct", near Crailo&action=edit&redlink=1 "Crailo (Huizen) (not yet drafted)") in the Netherlands, runs 800 m and covers a road, a railway and a golf course.

Wildlife passes are becoming increasingly common in Canada and the United States. Recognizable wildlife passes are found in Banff National Park in Alberta, where vegetated overpasses provide safe passage over the Trans-Canada Highway for bears, elk, deer, wolves, and many other species (Clevenger 2007). The 24 wildlife crossings in Banff were built as part of a highway improvement project in 1978 (Clevenger 2007). In the United States, thousands of wildlife crossings have been built over the past 30 years, including drainages, bridges, and overpasses. These have been used to protect mountain goats in Montana, Ambystoma maculatum in Massachusetts, bighorn sheep in Colorado, desert tortoises in California, and endangered Florida panthers in Florida (Chilson 2003).

The benefits derived from constructing wildlife crossings to extend migration corridors for wildlife above and below major roads appear to outweigh the costs of construction and maintenance. One study estimates that adding wildlife crossings to a highway project represents a 7-8% increase in the total cost of the project (Bank et al. 2002[6]​). Theoretically, the monetary costs associated with constructing and maintaining wildlife crossings in ecologically important areas are less than the benefits associated with protecting wildlife populations, reducing vehicle damage, and saving the lives of motorists by reducing the number of wildlife-vehicle collisions.

A study completed for the Virginia Department of Transportation estimated that wildlife crossings become cost-effective, in terms of property damage, when they prevent between 2.6 and 9.2 collisions with deer per year, depending on the cost of the wildlife crossing. Approximately 300 deer crossed through wildlife crossings in the year the study was conducted (Donaldson 2005).

Contenido

Un número de estudios ha sido conducido para determinar la efectividad de los Pasos de fauna en proporcionar conectividad de hábitat (al proveer corredores de migración viables) y reduciendo las Colisiones fauna-vehículos. La efectividad de estas estructuras parece estar muy relacionada con los sitios específicos (debido a las diferencias en ubicación, estructura, especie, hábitat, etc.) pero los cruces han sido beneficiosos a un número de especies en una variedad de ubicaciones. Las historias de éxito de Pasos de fauna incluyen:.

Banff National Park

Banff National Park offers one of the best opportunities to study the effectiveness of Wildlife Passes as it contains a wide variety of species and is separated in two by a large commercial highway called the Trans-Canada Highway (TCH). To reduce the effects of the four-lane THC, 24 wildlife passes (22 underpasses and two overpasses) were constructed to ensure habitat connectivity and protect motorists (Clevenger 2007). In 1996, Parks Canada (that country's national parks agency) developed a contract with university researchers to evaluate the effectiveness of crossings. The first decade of the 21st century produced several publications analyzing the impacts of wildlife crossings on various species as well as on overall wildlife mortality.

Using a variety of techniques to monitor the passes since their creation, scientists report that 10 species of large mammals (including deer, deer, black bear, grizzly bear, mountain lion, wolf, moose, and coyote) have used the 24 passes in Banff a total of 84,000 times as of January 2007 (Clevenger 2007). The research also identified a "learning curve" showing that animals need time to acclimatise to using Wildlife Passages. For example, grizzly bear crossings increased from seven in 1996 to more than 100 in 2006, even though the actual number of individual bears using the structures remained constant during this time, at between two and four bears (Parks Canada, unpublished results). A similar set of observations was obtained for wolves, with crossings increasing from two to approximately 140 over the same 10-year period. However, in this case the actual number of wolves, in the packs using the crossings, increased dramatically, from a low point of two to a high point of more than 20 individuals. In line with these results Clevenger et al. (2001) reported that the use of wildlife crossings and fencing reduced traffic-induced mortality of large ungulates on the TCH by more than 80 percent. However recent analysis for carnivores showed that the results were not as positive for this other group, with bear mortality increasing on average 116 percent in direct parallel to the increase in highway traffic volumes, clearly showing that fencing had no effect in reducing bear mortality (Hallstrom, Clevenger, Maher and Whittington, in prep). Investigations of passes in Banff have shown a mixed value for wildlife passes, depending on the species in question.

Parks Canada is currently planning to build 17 additional crossings along the TCH to increase motorist safety near the town of Lake Louise. The lack of effectiveness of standard fencing in reducing bear mortality demonstrates that additional measures, such as T-fences, may be necessary to effectively mitigate for bears (Hallstrom, Clevenger, Maher, and Whittington, in prep).

In 2010, ARC Solutions – an interdisciplinary partnership – initiated the International Wildlife Crossing Infrastructure Design Competition for a wildlife crossing on Interstate 70 (I-70) near Denver, Colorado. I-70 is known as the "Berlin Wall" for Colorado wildlife and designers had to take into account many challenges unique to the area, including snow and severe weather, high elevation and steep grades, a six-lane highway, a bike path and high traffic volumes, as well as multiple species of wildlife, including bobcats.[8]​.

After receiving 36 proposals from nine countries, a jury of internationally acclaimed experts in the disciplines of landscape architecture, engineering, architecture, ecology and transportation selected five finalists in November 2010 to develop their conceptual designs for a wildlife passage structure.[9] In January 2011, the team led by HNTB with Michael Van Valkenburgh and associates (New York) was selected as the winner.[10] The design features a single span of 100 m (328 ft) concrete across the road, which is planted with a variety of vegetation types, including a pine forest and prairie grasses, to attract different species to cross. A pre-cast modular design means that much of the bridge can be built off-site and moved into place.[11]​.