Since the mid 1970s, collisions between vehicles and large mammals on the Trans-Canada Highway (TCH) have been a concern of the parks in Canada. The construction of wildlife overpasses along the TCH began in the mid 1980s with the twinning of the highway from the east park entrance to the junction with the Bow Valley Parkway.
These bridge structures and various underpasses were installed at strategic locations in the park, providing safe passage to wildlife and hopefully minimizing traffic.
Banff National Park and its environs in Alberta are among the world’s best testing sites for innovation passageway to alleviate the effects of roads on wildlife. This has helped maintain large mammal populations for the past 25 years and has allowed the gathering of valuable data.
In the mid 1990s, research began to determine the effectiveness. Early results showed that the underpasses were very effective for elk, deer and coyotes, but that larger carnivores like wolves, cougars, black and grizzly bears were reluctant to use them. The overpasses were built as a result. Today, they are finding that many animals are beginning to adapt to the underpasses.