Colorado wildlife overpass cuts Interstate 25 collisions by 91%
A Colorado wildlife overpass spanning Interstate 25 between Denver and Colorado Springs has cut wildlife-vehicle collisions by 91% in the 10 months since it was completed, according to a newly released report.
Colorado wildlife overpass cuts Interstate 25 collisions by 91%
The Colorado wildlife overpass over Interstate 25 has delivered a 91% drop in wildlife-vehicle collisions in the 10 months since it was completed, according to a newly released report. Before the crossing system existed, the corridor averaged one wildlife-vehicle crash a day, according to the Colorado department of transportation.
A bridge over six lanes of Interstate 25
The overpass sits between Denver and Colorado Springs, the state's two biggest cities, and spans six lanes of traffic. It connects 39,000 acres of habitat on both sides of the interstate. The region is known for high movement of large game.
- The bridge measures 200ft wide and 209ft long
- It is covered in grass, with gradually sloped entrances for animals
- It is the centerpiece of a larger system of miles of 8-ft tall fencing and five large wildlife underpasses
Before the crossing, a crash a day
The system of fencing and wildlife underpasses is what funnels animals toward the safe crossing. State officials note that underpasses and tunnels on their own often do not work for big animals such as bull elk, because they restrict mobility and do not accommodate antlers.
Chuck Attardo, the environmental manager for the Colorado department of transportation, explained why the open overpass design suits the animals that live along the corridor.
"Elk and pronghorn like these big open structures where they can see for miles in each direction."
Elk, pronghorn and a jumping mouse cross
Officials have tracked a long list of species using the interstate 25 wildlife crossing, including elk, bears, pronghorn, northern leopard frogs, mule deer, coyotes, rabbits, frogs and the threatened Preble's meadow jumping mouse.
Pronghorn, according to Attardo, spent decades searching for a way across I-25 on their route from Trinidad to Greenland. With the overpass open, they now use the structure and have reached the west side of the interstate for the first time in decades.
Brandon Marette, a wildlife biologist for Colorado parks and wildlife, told CBS News that an elk crossing with her calf was among the moments that moved him most.
"That elk with her calf was just standing there in safety."
Cheaper than budgeted, with more to come
The project received $22m in federal funding and $8m from the state, but officials say they completed it for $15m. Research has shown overpass systems nearly eliminate wildlife-vehicle accidents and often pay for themselves by preventing costly crashes.
Nearly 20 wildlife crossings are under way in the US, with the Colorado structure currently the biggest. The Colorado department of transportation says it is hoping to build other wildlife crossings across the state.
