NewsState of 208


State of 208: Moving a mountain

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Posted at 12:22 PM, Nov 21, 2021
and last updated 2021-11-21 14:22:15-05

It's one of the most challenging road construction projects the state has ever seen. The stretch from Smith's Ferry to the Rainbow bridge requires basically moving a mountain.

And it comes with plenty of risks. Just this week a rockslide closed the section to holiday travelers. Project Engineer Alex Deduck took us on a behind-the-scenes look at how crews work to stabilize the hill after they're done blasting. "I brought you here just to kind of show off the repeating pattern of failure planes you can see the flat section right here and then about one hundred feet into the mountain it repeats again and that's what kind we have throughout this project."

So, pins are strategically placed to shore up parts of the new hillside. "The goal with the pins is to drill through these failures and connect them so that when they want to slide, they have all of these metal reinforcements to prevent it from sliding." Then a huge metal mesh blanket covers the slope. Some of the new slopes don't need a mesh covering but there are still huge boulders that are looking down at the highway. Crews repel down from the top to mark and then secure the rocks.

I.T.D. has worked closely with the Payette River Scenic Byway to make sure to maintain the natural beauty of the river. "As far as the river alignment we have not touched the course of the river, it is still the same."

You can't talk about the Highway 55 widening project without bringing up the historic Rainbow bridge. We just found out this week, that the Idaho Transportation Department has a new bridge on their seven-year plan. Jake Melder from I.T.D. explains. "The game plan is to construct a new bridge a little bit further north and build the road to make an easier transition, not that herkie jerky curve. It'll be a little bit straighter." The Rainbow bridge will be preserved as a pedestrian bridge with its own turnout.

For now, continue to use patience and take your time.