Special I-90 overpass will help animals cross safely
On Tuesday, the [Washington] state Department of Transportation will break ground east of Snoqualmie Pass on the state's first freeway overpass for animals. The 150-foot-long structure is designed to provide safe passage for species ranging from black bear and cougar to deer, elk — and even squirrels, mice and lizards.
It's part of an ambitious project to convert a 15-mile stretch of interstate into one of the world's most wildlife-friendly highways....
The wildlife structures are being piggybacked on a nearly $1 billion project to widen I-90 from four lanes to six, straighten curves, reduce avalanche hazards and generally improve driving conditions on one of the nation's busiest mountain highways....
Gold Creek and other underpasses will all be planted with native vegetation, to blend seamlessly with the surrounding environment. Tangles of wood and piles of rock scattered under the Gold Creek bridges serve as avenues and hiding places for small creatures, like pikas, voles, shrews and snakes....
Tweaking bridges to accommodate wildlife may not be much of a stretch for a transportation agency, but building overpasses strictly for wildlife is unprecedented in Washington. Plans call for at least two and perhaps more, if funding allows.
The first will be located at Price Creek, just east of Keechelus Dam. The site was picked based on topography and monitoring that found the area is a natural wildlife corridor.
Scheduled to open in 2019, the $6.2 million overpass will also be planted with native vegetation. Ideally, animals will stroll across undeterred by cars and trucks zipping past under their feet, White said....
It's not clear how that cost-benefit equation works out for I-90, with an average of four to five serious vehicle-animal collisions a year in the project area. It's also hard to estimate how much the wildlife crossings add to the total cost, since all the bridges and culverts had to be replaced anyway, White said.
The price tag for the first seven miles is $551 million, funded through a gas tax imposed by the Legislature in 2005. WSDOT estimates it will cost an additional $390?million, which hasn't been budgeted yet, to complete the final eight miles.
