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Wolf Lodge Overpass in North Idaho rebuilt to improve safety

A recent project in District 1 just east of Coeur d’Alene replaced the Wolf Lodge Interchange on Idaho Highway 97 with a taller (17’-4”), wider (43 feet edge to edge), longer (211 feet long) interchange. The bridge structure is located on ID–97 over Interstate 90 at exit #22. The project improved safety and increased vertical clearance over the outside shoulder of eastbound Interstate 90, allowing larger trucks to travel on I-90 in the area.

The old interchange, built in 1960, had many deficiencies, including excessive spalls and cracks, exposed rebar in the abutment and pier, plus substandard vertical clearance and shoulder widths. Shoulder widths increased from 2’-0” to 7’-8” in the rebuild.

This project used Ultra High-Performance Concrete (UHPC), a material used internationally but not widely used in Idaho or the nation. It was the first bridge structure built in Idaho using UHPC for the closure pour of deck bulb tee girders. The UHPC provided a strong, durable and maintenance-free connection for the deck bulb tee girders.

After the project, ITD’s District 1 office was asked to present information on this material to a contracting group in Las Vegas.

The project also used adaptive lighting on the interchange. When the technology doesn’t pick up a car in the area, the lights are dim. When it senses a car, it lights up. It’s a compromise between ITD’s concerns for safety and locals’ concerns with protecting the visibility of the night sky. The intensity of the new lighting changes based on time of day, traffic volumes, and weather conditions.

ITD District 1 and the Bridge section designed the project. The Accelerated Bridge Construction (ABC) method was used to expedite construction so that it was done in two stages, only taking four months. The bridge design used precast elements for the substructure, deck bulb tee girders, UHPC and a very minimum amount of cast-in-place concrete.

It would have taken 10 months to build the bridge using conventional cast-in-place construction. Use of ABC construction significantly reduced traffic impacts for the thousands of vehicles that travel over the interchange each day. About 20% of the vehicles that travel through the interchange are commercial trucks.

The project construction cost was $4.7 million.

The primary partners/stakeholders are the city of Coeur d'Alene, the city of Harrison, the city of St. Maries, Kootenai County, Benewah County, and the Coeur d'Alene Tribe.