Usually, bridges are built for cars, trains, or non-motorized transportation. But a new overpass designed by WSP USA was built specifically to link animal habitats separated by an interstate highway.
Located at the top of Parley's Canyon near the Salt Lake and Summit county line, the bridge is the first one built for this purpose in Utah … though if it proves successful in its intent, it may not be the last.
“It is the first overpass in Utah designed to accommodate wildlife and not humans,” said Joshua Sletten, WSP project manager and senior supervising engineer. “It is longer than most wildlife crossings and is intended for large animals like moose, elk and deer.”
The $5 million bridge is about 320 feet long, 50 feet wide, and spans three westbound lanes, four eastbound lanes, and the median along Interstate 80 (I-80). The overpass provides safe passage for animals entering and leaving the Snyderville Basin and the Wasatch Back. It is a corridor that has experienced hundreds of animal-vehicle collisions over the past 10 years.
“This bridge helps eliminate vehicle/wildlife conflicts through a corridor that had become known for collisions with animals,” Sletten said. “Today, wildlife is better protected, drivers are safer and congestion due to these collisions has been greatly reduced.”
WSP served as the prime designer, providing structural engineering as well as support for civil and geotechnical engineering, and landscape architecture. The firm worked on behalf of the Utah Department of Transportation (UDOT), the Utah Division of Wildlife Resources (DWR), Salt Lake City, Salt Lake County and Summit County.
Preliminary design began in January 2017, with construction starting in early 2018. The final landscaping boulder was placed on the bridge during a Dec. 13 ceremony, which marked its official opening as a wildlife crossing. That ceremony was also the last time people were permitted to walk across the overpass.