Deer Fence and Wildlife Crossing Under US 550, North of Aztec. (NMDOT)
New Mexico Department of Transportation
New Mexico's Reduction of Animal-Vehicle Collisions
On New Mexico's U.S. 550 North, the rate of animal-vehicle collisions in 2002 and 2003 dropped from 44 percent to 21 percent of all vehicle crashes during that period, thanks to 3 miles of improved deer fencing and 4 miles of new wildlife underpasses.
This successful reduction of animal-vehicle collisions is just the beginning, according to environmental specialists at the New Mexico Department of Transportation (NMDOT) and the New Mexico Department of Game and Fish (NMGF). Together, the two agencies have identified five major wildlife-migration corridors across the state: U.S. 550 from Aztec to the Colorado state line; U.S. 64 east of Raton; U.S. 54 south of Corona; U.S. 70 east of Las Cruces at the San Augustine Pass; and I-40 east of Albuquerque and through Tijeras Canyon. In each of these corridors, where animal-vehicle collisions had accounted for more than 40 percent of all vehicle crashes, NMDOT and NMGF aim to cut that ratio by half. So far, they have exceeded that goal.
On the "I-40 GRIP" project in Tijeras Canyon, 8 miles of deer fencing are being installed and five wildlife underpasses enhanced. Tijeras Canyon has been identified by NMGF and several national environmental groups as the most critical wildlife crossing area in New Mexico. Mule deer, black bear, and other wildlife migrating between the Sandia and Manzanita Mountains have been hit by vehicles on a regular basis.
To install 8-foot-high deer fences along the I-40 route, crews had to remove existing 4-foot-high barbed-wire fencing--barriers deer could easily jump over and sometimes push through. To enhance the existing culvert-underpasses, the crews faced an even bigger challenge: Some of the culverts had drop-offs at the entrances, none had natural floors, and all had approaches filled with non-native vegetation unattractive to wildlife. The crews built gabion ramps (rock- and dirt-filled baskets seeded with native plants) leading to the culverts, and attached 4-inch-high baffles to the bottom of each culvert to trap sediment and create a more natural floor. Volunteers from the Tijeras Canyon Safe Passage Coalition cleared the non-native vegetation in the culvert approaches.
When the I-40 wildlife-crossing improvements are completed, there will be a significant drop in animal-vehicle collisions. The project will even link two genetically isolated species of mountain lion. The arroyo river from which I-40 wildlife drink will stay clean, thanks to a partnership with Carnuel Land Grant to control runoff into the narrow arroyo. More wildlife crossings will be constructed in 2007 on U.S. 54 south of Corona and on U.S. 64 east of Raton.
The NMDOT's role on the project did not go unnoticed. In 2005, the NMDOT won a conservation award from the New Mexico chapter of the Wilderness Society.
For more information, contact Jeffrey Fredine, Jeffrey.Fredine@state.nm.us