Overview
The Idaho Transportation Department is reconstructing the interchange at Interstate 90 and State Highway 41 in Post Falls. This project will improve safety, increase capacity, provide better connectivity to SH-41 and position I-90 for future expansion.
The new interchange will feature a single point urban interchange (SPUI) where all ramps will converge at a single point controlled by a traffic signal. Upgrades to the interchange include replacing existing bridges, building new bridges, re-aligning on- and off-ramps, and improvements to the SH-41 trail and Centennial Trail which will provide safer travel options for pedestrians and cyclists.
Construction began in 2022 and is expected to be complete in 2026.
Construction updates
I-90 WESTBOUND OFF-RAMP NOW OPEN! CHANGES TO BUSINESS ACCESS – PLAN AHEAD
Here’s what to expect:
- State Highway 41:
- Traffic is shifted to the newly constructed lanes on the west side of the roadway. Business access has changed. Click here for an access map.
- I-90 westbound on-ramp:
- Traffic is shifted to a temporary configuration with one lane open.
- I-90 eastbound off-ramp:
- Traffic is shifted to a temporary configuration with one turn lane in each direction.
Work will include:
- Building the new westbound off-ramp at SH-41.
- Building the new SPUI operation.
- Widening SH-41 to Mullan Avenue.
- Finishing the SH-41/Mullan Avenue intersection.
What to expect in 2026
- Crews will work Monday-Friday from 7 a.m. to 5 p.m.
- Night work will be scheduled from 8 p.m. to 5 a.m. During special events, night work will begin at 10 p.m.
- The speed limit is 55 mph on I-90 and 25 mph on SH-41 and Seltice Way.
- Lane restrictions on SH-41.
- Mullan Ave. will be restricted to one lane in each direction.
- Intermittent lane restrictions will occur on I-90 at night.
- Nighttime work will require lighting.
- Construction may be noisy and dusty.
For live traffic impacts, check 511.idaho.gov.
Neighboring construction projects
ITD and city of Post Falls have several projects on or near I-90 in Kootenai County that may have an impact on traffic or detour routes established as part of the I-90, SH-41 Interchange project. See the map below for details.
Fly over the design
Funding
The Idaho Transportation Board approved a bond sale in February 2022 to advance the project to start construction one year early.
Elements of this project are being funded with the Transportation Expansion and Congestion Mitigation (TECM) funds as part of Governor Little’s Leading Idaho initiative. The program allows ITD to accelerate project timelines to address rapid growth and build critical infrastructure today that would otherwise take many years to fund and build.
The project was awarded to Scarsella Brothers, Inc. for $78 million.
Timeline
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Spring 2018
Early design
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Fall 2018
Value planning with local stakeholders and public presentation of alternatives
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Winter 2018
Preferred alternative selected
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May-June 2020
Online hearing for planned improvements and construction staging
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2022-2025
Construction underway
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2026
Construction expected to be completed
Frequently Asked Questions
Noise walls were not warranted in the analysis of the interchange, but a study is underway to look at expansion of I-90 and if it’s warranted in the corridor.
The design team consulted with other community partners like emergency services and law enforcement to mitigate any safety concerns with the construction of pedestrian underpasses. The underpasses will be well-lit and short enough to see through to maximize visibility and safety.
Both underpasses will be 14 feet wide and 10 feet tall, which makes them larger than the underpass to access Silverwood off US-95. The inside of the underpass under the I-90 westbound on-ramp will be visible from Seltice Way, and the underpass under SH-41 will be visible from Primrose Lane, which will help improve safety and ease of patrolling.
SPUIs control traffic at one signalized point. By using one signal, rather than two signals, to control movements, the SPUI design is expected to increase capacity and decrease travel times. This design will achieve the efficiencies of a SPUI with excellent compatibility with future expansion.
It is important to keep this interchange open to traffic during construction. If ITD could completely close the interchange, construction could occur much more quickly. This complex interchange construction project involves building significant infrastructure such as:
- 1.3 miles of I-90 pavement reconstruction
- SH-41 widening and pavement reconstruction from Seltice Way to 12th Ave
- ½ mile of widening and pavement reconstruction of Seltice Way
- Six permanent bridges
- Two temporary bridges
- Eight retaining walls
- Two pedestrian underpasses
- One pedestrian bridge
- Upgrades to intersections with three traffic signals
- One pedestrian (“hawk”) signal
Utilities, drainage, and signage improvements throughout the project limits
Modeling shows that once constructed the new interchange will be safer, more efficient and easier to navigate while being compatible with future expansion of SH-41 and I-90.
Access to businesses on SH-41 north of the interchange will remain the same, though a new median barrier will not allow left turns onto or from the highway. Access will continue to be provided primarily through side streets or signalized intersections to improve traffic flow and make it safer.
Most local roads will continue to function the same as they do now, though access to the freeway south of the interchange will be simplified. Ross Point Road will be restriped to accommodate additional street parking. Other changes to traffic control, speed limits and parking may take place after construction by the city as modifications are not supported by traffic modeling.
Commuters from Spokane:
- Speed limits will be reduced, but other impacts will be minimal during commute times.
Businesses adjacent to the interchange:
- ITD will work with businesses to maintain access and place temporary signage for construction.
Bicyclists/pedestrians:
- ITD will maintain bicycle/pedestrian access through the construction zone. Detours will be in place whenever needed.
Contact the project team
For questions or comments about this project, please contact the project team at info@i90corridor.com or (208) 772-1200.
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