Construction crews are preparing for a long night of construction. The Idaho Transportation Department is placing the girders for the Northgate Interchange bridge Tuesday and Wednesday.
From 10 p.m. to 5 a.m., Interstate 15 will be closed from the I-86 interchange to exit 89, just south of Blackfoot.
It’s nearly a 20-mile span, but project managers say this is the last big interstate road closure for at least the next three years.
“They’ll span from the abutment over to the center pier. They’ll support the bridge deck,” Greydon Wright, ITD engineering manager said. “We’ll do that for northbound lanes tonight and tomorrow night will be the southbound lanes.”
Crews will install 12 girder Tuesday and another 12 Wednesday. Each girder is 85 feet long, weighing upwards of 120,000 pounds.
It’s a big job but it, “should be the only time we physically have to close the interstate to bring these in,” Wright said.
Although this shutdown could be a nuisance to drivers, safety is ITD’s main priority.
“The risk and the safety of the workers and the traveling public, that’s why we’re detouring them up U.S. 91 and doing the work at night. It’s over 30,000 cars a day,” Wright said.
At night, there are just under 500 cars an hour. However, this is the last big step for this project. Fortunately, this is the final closure in this area until 2022.
I-15 will reopen Wednesday morning at 5 a.m. but then will close again for completion Thursday night. ITD predicts the interchange to be finished in early October.