Commuters and outdoor recreationists aren't the only ones who traverse Idaho 21 along what is known as the Ponderosa Pine Scenic Route. Each year, large numbers of deer and elk travel in the corridor and are killed as they attempt to cross the highway.
ITD and a multi-agency partnership will build an underpass near milepost 18 this summer to improve safety for motorists and protect wildlife that use the corridor. The participating Boise River Wildlife Linkage Partnership is a group of concerned citizens, businesses, non-profit organizations and city, county, state and federal agencies.
The structure and wildlife fencing will be constructed to help get deer and elk under Idaho 21. The plan includes, as funds become available, extending the wildlife fence on the east side of the underpass to increase use and function of the structure.
Photographs of the construction area and a rendering of how the completed structure will look are available on ITD's Facebook page.
"There are too many vehicle-wildlife collisions occurring on this stretch of highway," said ITD environmental planner and biologist Scott Rudel. "Simply put, what it comes down to is that we can do a better job protecting people and protecting wildlife than what now exists. ITD and the Boise River Wildlife Linkage Partnership believe this project is an investment for the people of Idaho in their safety, quality of life and in protecting their natural and cultural resources."
In the past eight months, 69 vehicle-wildlife collisions have been posted on the "Give Deer and Elk a Brake" tally signs.The signs represent the number of incidents on an 11-mile stretch of Idaho 21 beginning near Discovery Park at Lucky Peak Reservoir and ending at the highway’s intersection with Robie Creek.
The high number of vehicle-wildlife collisions is attributed to mule deer and elk migrations in the fall from summer range high in the Sawtooth and Boise Mountains and winter range on the west slope of the Boise Front. The semi-annual migrations are a major concern for motorists and wildlife specialists.
Federal stimulus funds will be used to construct the bridge and a portion of the fences. McAlvain Construction is the contractor for the $756,000 project. Wildlife underpasses are becoming more common in the West as agencies seek ways to improve highway safety for motorists and wildlife.
"Physically separating motorists and wildlife is the best way to protect both," said Ed Bottum, Idaho Department of Fish and Wildlife habitat biologist. "The tally signs are there to remind motorists of the hazard posed by deer and elk on the highway… Currently, raising driver awareness is our only real option, but with this project we hope to change that."
Construction of the wildlife underpass bridge will begin in July and will be completed by early fall. Traffic will be re-routed around the construction area on a temporary bypass next to the highway. Temporary signals will control traffic.