Banff National Park hosts the world's longest-running wildlife crossing research program, monitoring a system of 44 overpasses and underpasses along 82 kilometers of the Trans-Canada Highway since the 1990s.
Cameras have documented more than 250,000 wildlife crossings since monitoring began, with the crossing structures and accompanying fencing reducing wildlife-vehicle collisions by more than 80% overall — and by 96% specifically for elk and deer.
Source: Banff wildlife crossing research program; Yellowstone to Yukon Conservation InitiativeThe Yellowstone to Yukon (Y2Y) Conservation Initiative extends the corridor concept across a 3,400-kilometer stretch of connected wilderness, aiming to keep large carnivore and ungulate populations genetically and demographically connected across the U.S.-Canada border region.
Wildlife corridors are one of the rare conservation interventions where the before/after data is genuinely clean: roads either had collisions or didn't, crossings either got used or didn't. This makes Banff's results some of the most citable evidence in conservation infrastructure — though we'd caution that results from one well-funded, well-studied park may not automatically transfer to lower-budget crossing projects elsewhere.
Newer crossings, such as the Rock Creek underpass completed in late 2024, do not yet have multi-year collision data — 2024 figures show roughly half the prior seven-year average of animal strikes, but the structure wasn't finished until late in the year, making it too early to draw firm conclusions.