ITD starts major construction on Idaho 55 between Boise and McCall. Closures planned
The Idaho Transportation Department began work Tuesday to upgrade a section of Idaho 55 marked by its narrow roadway and steep embankments, meaning road closures and potential delays for people traveling between the Treasure Valley and the McCall area.
Officials said it will take about two years to complete the 1-mile project between Smiths Ferry and the Rainbow Bridge, about 60 miles north of Boise. That portion of the road is particularly windy, with narrow shoulders and embankments to one side and rocky outcroppings on the other.
The construction will widen the shoulders and straighten parts of the route, which should improve motorist safety on a stretch of the road that Alex Deduck, the ITD engineer heading up the project, said has around three times as many crashes as other parts of the route. Currently, Deduck said, the road is “two 12-foot lanes and essentially no shoulder.” When the project is completed, it still will have two 12-foot lanes, but each shoulder will be 4 feet wide. ITD estimates the project will cost around $25 million.
Construction started Sept. 8 according to an ITD site for the project. Through November, the road will be fully closed between 10 a.m. and 2 p.m. Monday through Thursday. Construction will continue day and night, seven days a week, with alternating one-way traffic controlled by a temporary traffic light.
Deduck said all construction will end during the winter months and resume in the spring with the same closure and single-lane schedule from this fall. During the summer, traffic between Boise and McCall increases significantly. To accommodate that traffic, both lanes will be open from Friday afternoon through Sunday, and during the week flaggers will direct alternating one-way traffic.
Deduck and ITD spokesman Vince Trimboli said the coronavirus pandemic has affected longtime traffic patterns on Idaho 55. Traditionally, the bulk of traffic was on the weekends with weekdays much less busy — hence the weekday restrictions. Since the pandemic hit Idaho in March, Trimboli said, the department has seen many more travelers using the road during the week. He encouraged motorists to be aware of potential construction delays or closures on Idaho 55 before hitting the road. Live updates are available at 511.idaho.gov.
“The last thing we want is somebody to get stuck this fall,” Trimboli said.
Crews will be blasting rock from the hillside to widen the roadway, and Deduck said the short “blasting window” is part of why the construction will last until late fall 2022.
The project is one that the department has had planned for many years, but funding shortfalls as well as the complex nature of the project pushed it back two decades.
This story was originally published August 27, 2020 at 4:00 AM.
