Owner Minnesota Dept. of Transportation-District 1
General Contractor/CM Kiewit Infrastructure Co.
Lead Design Firm/Structural Engineer Parsons
Civil Engineer SEH Inc.
Key Subcontractors All Phase Contracting; Alpine Steel Inc. (JD Steel); Badger Daylighting Corp.; Barr Engineering Co.; Braun Intertec Corp.

Due to its easement agreement with a mining company, the Minnesota Dept. of Transportation had to relocate 3.2 miles of U.S. Highway 53 in the Mesabi Iron Range in northern Minnesota to allow mining operations to continue. Contractor Kiewit Infrastructure Co. had only two years to construct the roadway, which included a 1,132-ft-long, 92-ft-wide and more than 200-ft-tall structural steel bridge—the state’s tallest—over an inactive water-filled open-pit iron mine that also acts as a drinking-water source for nearby communities.

Because of the aggressive schedule, permitting and design were performed concurrently, a risky strategy if permitting didn’t go as planned. Despite this, the team delivered the project five weeks ahead of schedule, with no OSHA recordables or lost-time injuries during 600,000 worker hours over the two-year construction schedule.

“This project demonstrates you can have outstanding performance and still build extraordinary engineering and construction without hurting people,” says one safety judge. Crews faced challenges such as limited access with nearly vertical rock face walls and a life-threatening winter climate, with temperatures as low as -40° F.

Other safety contractor concerns included fall protection, blasting, night work, highway traffic and heavy crane picks in excess of 750,000 lbs.

The project team established a safety culture that not only kept workers safe, but also safeguarded nearby residents, commuters and wildlife, according to the submitter. “This was not an ‘inside the fence-line’ type job,” says a safety judge. “There were lots of challenges with the public.”

After observing Kiewit’s rigorous safety culture, MnDOT adopted several parts of the program into its standard practice, according to agency officials. The team also shared best practices and subcontractor safety management through a formal three-way contractual agreement between Kiewit, MnDOT and OSHA.

ENR's Best of the Best Projects 2018