skip to main content
Idaho Official Government Website Contact Us

I-90, ID-41 Interchange

Traffic volumes continue to grow, prompting the redesign of the interchange to safely accommodate more drivers.

Read MoreAsset 1
Contact usAsset 2
Response to comments
online hearing in May and June

Fly over the design

Skip the reading, and watch this 6-minute video on how the new interchange will look and function.

Interchange design

The new interchange is planned to be a single-point urban interchange (SPUI), also pronounced as “spooey.”

SPUIs control traffic at one signalized point. By using one signal, rather than two signals, to control movements, the SPUI design will likely be more efficient and decrease travel times. This design will achieve the efficiencies of a SPUI interchange with excellent compatibility with future expansion for an estimated $39 million.

To experience a 360 degree tour of the interchange, click the link below.

click through the design

Design details

The highway will still shift to the west and pass under I-90. Ramps will meet at a single point just north of the interstate. Eastbound ramps will pass underneath the interstate to connect with the highway. The westbound off-ramp will be elongated and will not curve.

Because the interchange will be shifted north, there will be fewer impacts to the local system. The signal currently controlling the Ross Point Road, Seltice Way, ID-41 and I-90 intersection will be removed and replaced with a stop sign at Ross Point Road. After being shifted, the highway will connect with Seltice Way at Herborn Place and be controlled with a signal.

After construction, the Centennial Trail will likely pass underneath the interstate and continue north. A connection to the neighborhood south of Seltice Way will be constructed.

View updated design

Seltice to Mullan

In spring 2019, the limits of this project were expanded to include the ID-41 and Mullan Avenue intersection–which was set to be improved within a few years after the interchange redesign–to ease construction impacts and to bring benefits to the public sooner.

Expected changes to the intersection include:

Mullan Avenue design

For path users

The new design calls for a better connection between the Centennial Trail along I-90 and the Prairie Trail along ID-41.

A new signal-like crossing will alert traffic to users who are on the Centennial Trail who would like to cross Seltice and head south. Otherwise those users may head north by using a short tunnel to pass underneath the future eastbound on-ramp and cross under mainline I-90 with ID-41 traffic. This section underneath mainline I-90 will include barrier to separate drivers and other users.

The path will cross over the westbound off-ramp via a bridge. At that point users can continue north on either side of ID-41 either by staying on the path on the east side or by using another tunnel to cross underneath ID-41 to the west side. Both paths will require users to be vigilant as they cross streets and business accesses as they do today.

Note that after expansion efforts for ID-41 are complete, the Prairie Trail will extend all the way from I-90 to Rathdrum.

View future path near ID-41
Spring 2018
Early design
Asset 5
Fall 2018
Value planning with local stakeholders and public presentation of alternatives
Asset 5
Winter 2018
Preferred alternative selected
Asset 5
Fall 2019
Open house for planned improvements and Mullan Ave
Asset 5
May - June 2020
Online hearing for planned improvements and construction staging
Asset 5
Spring 2023
Anticipated start construction
Asset 5

Downloads & Resources

Asset 5
February 2020

Response to public comments

In response to public comments received at the Nov. 2019 open house, ITD published a FAQ.

Asset 5
Nov. 2019

Open house

ITD held an open house to give comment on the updated interchange design, Mullan Avenue intersection and construction concepts.

Open house details
Asset 5
Spring 2019

Mullan Avenue added

The limits of this project were expanded to include the ID-41 and Mullan Avenue intersection--which was set to be improved within a few years after the interchange redesign--to ease construction impacts and to bring benefits to the public sooner.

Asset 5
January 2019

Preferred design selected

After receiving public feedback and continued discussions with the city of Post Falls, ITD has selected a new design to improve safety and capacity at the interchange. Called an offset SPUI, the latest design eliminates the loop ramp, reduces impacts to Seltice Way and achieves the efficiencies of a single-point urban interchange at a lower cost.

ITD will continue to develop details for the final design and construction.

Preferred design selected
Asset 5
Winter 2018/2019

Selecting an alternative

ITD is continuing coordination with local jurisdictions, and after evaluating public comments submitted after the open house, will select an alternative--whether it be the single-point urban interchange or the half-diamond interchange--to pursue. The decision will likely be made before 2019.

Asset 5
Fall 2018

Value Planning

ITD met with the city, planners and engineering firms to assess the needs of the project before creatively and collaboratively identifying solutions. Nine alternatives were explored by the group, and the department has selected two alternatives to present to the public at the meeting in early November.

Asset 5
Spring 2018

Early design

Engineers began collecting data to assess the needs of the project, ranging from traffic volumes to stakeholder identification, to develop various interchange designs.

Project
Updates

The design team reviewed comments following the May/June 2020 online hearing and developed responses to the most common concerns. Read more.

Frequently Asked Questions
You've got questions, we've got answers! Here are some of the most common questions we've received about this project.
General
With the planned expansion for ID-41 and the eventual expansion of I-90, will ITD build noise walls?
With the planned expansion for ID-41 and the eventual expansion of I-90, will ITD build noise walls?

Noise walls were not warranted in the analysis of the interchange, but a study will start in 2021 to look at what it would take—in terms of land and mitigation for adverse environmental effects like noise—to add a third lane to I-90. Noise walls may be included in future expansion of I-90 pending results of the study.

General
With traffic detoured to the half-interchange at Seltice to the west, how will drivers access the freeway with the extra traffic? There’s no dedicated turn lane or signal right now.
With traffic detoured to the half-interchange at Seltice to the west, how will drivers access the freeway with the extra traffic? There’s no dedicated turn lane or signal right now.

Temporary signals will be installed during construction to handle extra traffic seeking alternative routes. At this time the design team is still determining whether they will be used only during the closure of the westbound off-ramp or if they will be necessary for all of construction.

General
The tunnels and overpasses for bicyclists and pedestrians will maintain connectivity, but will they be safe?
The tunnels and overpasses for bicyclists and pedestrians will maintain connectivity, but will they be safe?

The design team has consulted with other community partners like emergency services and law enforcement to mitigate any safety concerns with the construction of pedestrian tunnels. The tunnels will be well-lit and short enough to see through to maximize visibility and safety.

Both tunnels will be 14 feet wide and 10 feet tall, which makes them larger than the tunnel under US-95 to access Silverwood. The inside of the tunnel under the I-90 westbound on-ramp will be visible from Seltice Way, and the tunnel under ID-41 will be visible from Primrose Lane, which will help improve safety and ease of patrolling.

General
The highway needs dedicated right turn lanes to access Mullan Avenue.
The highway needs dedicated right turn lanes to access Mullan Avenue.

The highway will be three lanes wide at this intersection, and by allowing traffic to go straight in all lanes, it maximizes the amount of traffic that can be cleared in one cycle of the signal. Drivers heading south on ID-41 will also need to be in the lane furthest to the right to head west on I-90, and by not designating that lane as a right turn lane only, there will be less weaving as drivers try to get to the freeway.

General
The ramps to access I-90 today are steep and aligned so that it’s hard to merge. Will that change?
The ramps to access I-90 today are steep and aligned so that it’s hard to merge. Will that change?

All of the new ramps will be longer, and the westbound off-ramp will no longer curve. Drivers will have extra time through the use of a parallel lane that extends past the merge point to join traffic. The design team will continue to plan signage that will help drivers determine which lanes will get them where they want to go.

General
With only one lane for the eastbound off-ramp, will traffic back up onto the freeway if there is a crash?
With only one lane for the eastbound off-ramp, will traffic back up onto the freeway if there is a crash?

Although the ramp will only be striped for one lane, it will have wide shoulders to keep traffic moving around most crashes as well as to provide room for staging during construction and future maintenance operations. ITD will also use signage to redirect traffic around crashes at that ramp, as it does now by changing messages at signs located near the state line. Another digital emergency sign will be placed on eastbound I-90 near Greensferry with this project.

General
Other ramps in Post Falls should be built or improved, like at Huetter, Greensferry and Seltice.
Other ramps in Post Falls should be built or improved, like at Huetter, Greensferry and Seltice.

Existing interchanges in Post Falls are too close together to allow the construction of additional interchanges. Current standards call for interchanges to be spaced at least one mile apart to reduce conflicts between traffic merging onto the freeway and other traffic weaving to exit. As it is, there are no other city routes capable of handling traffic accessing the interstate.

There are no other plans to modify interchanges in Post Falls, but a planning study next year will evaluate whether existing access points need improvements.

General
Will stop signs be sufficient at Ross Point Road and Seltice?
Will stop signs be sufficient at Ross Point Road and Seltice?

Traffic control devices, like signals and stops signs, will stay in place for city intersections based on projected volumes and land use changes. The Ross Point Road and Seltice intersection will transition from a signal to a stop sign since it will no longer serve as the main access point to ID-41 and will become a T-intersection. Traffic will be unable to turn left from Ross Point Road onto Seltice.

Drivers on Third Avenue will have a stop sign to access Ross Point Road, but at Third Avenue and Herborn Place, the stop sign will be for drivers on Herborn Place.

Other changes to traffic control, speed limits and parking may take place after construction by the city.

General
How will the new design be compatible with other regional plans?
How will the new design be compatible with other regional plans?

The new interchange was designed to accommodate future traffic demands and to be compatible with other regional plans.

Future growth was modeled by pulling data from several sources, including: employment rates from the Department of Labor, structure data from Kootenai County, the 2010 national census, planned transportation projects and land use development as projected by cities in Kootenai County. Modeling supports the current design’s compatibility with expansion of ID-41 to three lanes and expansion of I-90 to six lanes. The base model was provided by Kootenai Metropolitan Planning Organization and used by the design team to evaluate how the project will perform with existing and future conditions.

Although not included in this project, ITD is seeking grant funds to relocate the Port of Entry to Huetter to minimize safety concerns posed by commercial traffic heading east through the interchange and up the grade.

General
Once constructed, how will the new interchange affect local roads?
Once constructed, how will the new interchange affect local roads?

Modeling shows that once constructed the new interchange will be safer, more efficient and easier to navigate while being compatible with future expansion of ID-41 and I-90.

Access to businesses on ID-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.

© Copyright 2020 Idaho Transportation Department Visit ITD Website

Contact us

Default Project Comment Form
Maximum upload size: 8MB
Maximum upload size: 52.43MB

Signup Form