Highway bridges for wildlife

Where it stands as of Sep 29, 2026

Colorado's I-25 wildlife overpass, the largest in North America, cut vehicle collisions on its stretch of highway by 91 percent in its first nine months, with elk, pronghorn and the threatened Preble's meadow jumping mouse all using it. The figure covers the whole system of five underpasses, fencing and the bridge, not the bridge alone. Nine months is a short record, and the state's 15-year payback estimate is an agency projection, not a measured result.