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I-90: Kellogg Dips

ITD continues to work with EPA to monitor any settlement and plan for emergency and long-term repairs to ensure the stability of the freeway underneath.

History and long-term repairs

Four locations on Interstate 90 began to sink in February 2019, and since then, ITD has partnered with several agencies, including the Environmental Protection Agency, to determine the cause and prepare a permanent fix.

In the following months, ITD lowered the speed limit as necessary and twice added more pavement to keep the roadway surface level and increase speeds.

The cause of the settlement remains unknown, but with the completion of the EPA facility adjacent to the freeway in late summer 2020 and the forming of another dip in the westbound lanes, ITD will continue to monitor the area to assess the need for emergency repairs in fall 2020 or spring 2021.

Long-term repairs could include excavating 30 feet down to a weak spot below the pavement or reconstructing the ballast section to bridge this soft spot where the freeway is settling; options range from $5 million to $25.5 million, and a project could be added to the program in fall 2021 and scheduled for 2028 or sooner. Only time will tell the scope of repairs needed.

July 2019

Monitoring continues

Settlement monitoring continues while the EPA completes work on their facility adjacent to the freeway. The EPA project is scheduled for completion by the spring, allowing further investigation into the cause of the issue. The presence of any activity next spring will help determine the scope and timing of a permanent fix. Repairs could take place summer 2020 or the following year.

April 2019

Site drilling

Drilling will help develop permanent repairs by collecting road data. Drivers can expect a single-lane closure on eastbound I-90 during drilling operations.

March 2019

Temporary Repairs

Another round of temporary repairs is scheduled for Friday, March 29. Drivers can expect single-lane closures during the day while crews are on site.

Repairs schedule
March 2019

Dips are stabilizing

Survey results show that the dips are not settling as quickly. Another round of temporary repairs and more drilling are expected in April.


As of August 2020, a new dip has formed in the westbound lanes just east of the previous dips. At this time ITD is not expecting to lower the speed limit, but now that the EPA has finished the facility adjacent to the freeway, both agencies will continue to monitor the area to determine the need for short-term repairs and plan for any long-term repairs. Another layer of pavement could be added this fall or next spring if the settlement worsens.

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