Along with the construction of a huge number of roads all over the world came to the problem of preserving migratory routes of many species of animals and the problem of their death under the wheels of vehicles. To this end the US and Europe are constructed bridges for animals.
Bridge over the overpass in Banff National Park, Alberta, Canada
The park has about 41 species of animals.
For them, created 6 bridges and 35 underpasses
A perfect example of such bridge in Holland:
Montana, United States
The bridge for migration of red crabs, Australia
Lake Keechelus, US