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Major overhaul of dangerous I-90 bridge in Yellowstone County scheduled for fall

bridge rendering.png
Posted at 8:14 AM, Mar 11, 2021
and last updated 2021-03-11 10:14:23-05

No one looks forward to seeing those orange cones on the highway showing construction ahead, but a major project that will get underway this fall and last a couple years will eventually ease congestion and make a stretch of Interstate 90 in Yellowstone County safer for drivers.

It’s called the 1-90 Yellowstone River project, and it will mean big improvements to an approximate 2.6 mile stretch of the interstate between the 27th Street exchange and the Lockwood exchange, adding a third lane in each direction.

“The purpose of the project is to be able to accommodate to increase capacity, future traffic, operations and safety overall for the infrastructure of 1-90,” said Tim Erickson, transportation manager with HDR engineering.

A major part of the projects will be the reconstruction of two bridges that cross the Yellowstone River and a railroad spur line.

The westbound bridge that will be replaced was the scene of a huge pileup less than two weeks ago that involved approximately 30 vehicles.

Yellowstone River bridge diagram

A 2012 Montana Department of Transportation study identified the need for improvements for this section of 1-90. While construction preps begin this fall, the real work won’t kick into gear until the following year. The bridges were built back in the 1960s.

During season one construction, one of the existing bridges will be demolished. The traffic on the interstate will be shifted over to head-to-head traffic with a single lane in each direction over the existing bridge while a new bridge is built. Erickson says it will go back to its existing configuration with four lanes total during the winter so there won’t be head-to-head traffic during that time. It will be vice versa during the second season of construction.

Along with three lanes going each way, another big difference is that there will be a ten-foot shoulder on both sides of road in each direction.

The new bridge span is also being designed so that the piers minimize any impact to the water in the river below.

Improvements will also be made at the two interchanges on that stretch of the interstate.

“There are ramp modifications being done primarily for the offramps at both 27th Street and Lockwood interchanges—having dual exit ramps there to accommodate the increase in traffic that’s experienced at those interchanges,” said Erickson.


It will definitely mean some slowdowns in the coming years for drivers before the entire project is expected to be completed in 2024.

“They do take time to make long-lasting improvements to the overall infrastructure, but the goal is that these infrastructure improvements are very long-lasting far into the future,” says Erickson.

You can learn more about the 1-90 Yellowstone River Project and provide comments here: