4/9/2021
The Idaho Transportation Department provides debrief on ID-55 rockslide
SMITHS FERRY – In the wake of a rockslide on March 15 along Idaho State Highway 55 near Smiths Ferry, the Idaho Transportation Department has determined the slide was a localized event and, after additional mitigation, the greater hillside remains stable.
The slide occurred within a work zone where crews are cutting into the adjacent hillside to create extra room for ID-55 and enhance the overall safety of the road. The space will be used to reduce the severity of curves, construct wider shoulders, and add guardrail and pullouts.
Water from melting snow seeped into and destabilized the hillside at a cut crews created last fall. To prevent future localized slides, ITD is enhancing the reinforcement of the hillside as cuts are created. The Department has hired geotechnical experts to aid in this effort. This approach is expected to improve reliability of the hillside’s stability and the overall efficiency of the blasting work.
“Safety is the top priority of the Idaho Transportation Department. We are thankful no one was hurt during the rockslide activity on State Highway 55 last month,” said District 3 Administrator Caleb Lakey. “Hillsides and slopes become more unstable when doing work of this nature. We expect rock fall as a part of these projects. We had precautions in place to protect the traveling public in case of any slide activity and are doubling down on those precautions.”
ID-55 is now open to a single lane of alternating one-way traffic. Travelers should plan for a fifteen-minute delay at the project location. From now until late May, there will be daily closures Monday through Thursday from 10 a.m. – 2 p.m. to allow blasting and debris removal activity.
“I appreciate the public’s patience as we responded to this rockslide,” said Lakey. “We did not take the reduction of service on this critical corridor lightly. It’s a good reminder to drive attentive and be on the lookout for rocks on the roadway during the springtime.”
The project is anticipated to continue through Fall 2022. For more information, visit ITDprojects.org/id55smithsferry/