Wildlife crossings not only protect wildlife, they also promote human safety. A study of a Colorado State Highway showed an 86% reduction in the number of animal carcasses found along the highway and a 70% decrease in the number of wildlife-vehicle crashes reported to authorities in the first year after the installation of wildlife crossings like tunnels and bridges along with wildlife-friendly barriers.
Julia Kintsch et al., “State Highway 9 Wildlife Crossings Monitoring – Year 2 Progress Report,” Colorado Department of Transportation (March 2018): i-ii.