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Alternatives & Maps

Potential Intersection and Interchange Options

Level 3 evaluated each alternative’s potential benefits and impacts. Precise intersection locations and configurations may be refined as planning, environmental review, and design continue.

The first example shows Alternative B and its locations for intersections or interchanges. 

 

The example on the far right shows Alternative B’s impact area, including the intersection and interchange configurations used to score the alternative.

Interchange Options ON alternative B (Vector Map)

New Corridor Alternatives

Roadway Configurations 

Traffic forecasts help estimate the number of lanes needed to accommodate projected traffic through 2050. Final configurations would be phased during future project development. Lane configurations currently under consideration for each alternative section are shown on the alternative maps. Maps on meeting boards provide a view of the Moscow area, while roll plots show the full length of each alternative throughout the study area.

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roadway configurations examples

Screening and Refining Alternatives

Performance Measures 

In Level 3, the study team used specific criteria to refine and evaluate the alternatives. These criteria align with the study’s Purpose and Need and goals:

  • Reduce congestion 

  • Improve travel time reliability

  • Improve regional travel time

  • Support freight movements

  • Improve safety

  • Support community goals

  • Avoid and minimize environmental impacts

  • Support implementation

 

Refining and Combining Alternatives 

The study’s final recommendations may again combine route segments from different alternatives and quadrants, along with different intersection and interchange configurations.

How Your Input Can Shape the Study 

Tell us which elements you prefer and what concerns you have. Your feedback will help determine how elements are combined and configured in the alternatives recommended for further study.

New Corridor Alternative Results

ALTERNATIVE A: Warbonnet Drive

Eliminated​

ALTERNATIVE B: Idaho State Line

Carried Forward​

ALTERNATIVE C: Washington State Line 

Carried Forward​

ALTERNATIVE D: Airport Road Interchange

Not Recommended

ALTERNATIVE E: Airport Road Partial Cloverleaf

Carried Forward​

NO BUILD: 

The No Build option will be carried forward throughout the PEL and NEPA process

Carried Forward​

Additional Details 

 

Potlatch

Two new alignments are being considered near Potlatch and are carried forward for further analysis. These options are shown on the roll plots.

 

Rural Widening vs. Rural Improvements

Improvements north of Moscow to the Latah/Benewah county line were considered in Level 3. Alternative A was screened with spot improvements, and Alternatives B through E were screened with rural widening. Both widening and rural improvements will be carried forward as options for each alternative.

 

Palouse River Drive

Palouse River Drive is an important local connection but would not divert enough downtown traffic to meet the study’s Purpose and Need as a standalone solution. It was evaluated as a component of Alternatives B and D in Level 3.

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Minor improvements or realignments for Palouse River Drive are envisioned as potential City of Moscow projects. The existing alignment is unlikely to support SH-8 re-designation. However, a major future realignment in the southeast quadrant, similar to the connection shown in Alternative C, could be considered for re-designation.

Alternative A: Warbonnet Drive

Includes Rural Improvements North of Moscow shown on the corresponding roll plot​

Level 3 Screening Results: Eliminated

Key Findings 

 

  • Traffic Operations: Provides moderate congestion relief but no east-west connection for Troy to Pullman commuters. 

  • Freight: Provides limited freight benefit without a connection in the southeast quadrant. 

  • Safety: Provides some safety benefits with at least one grade-separated intersection and spot improvements north of Moscow. 

  • Property and Environmental Impacts: Has the lowest property and environmental impacts of the build alternatives, but considerable property impacts to the University of Idaho properties and businesses near Warbonnet Drive. 

  • Community Planning and Implementation: Has limited consistency with long-term regional planning documents. Has moderate potential for implementation and phasing.

Result: 

Alternative A is Eliminated​

alternative A map

Alternative B: Idaho State Line

Includes Rural Widening North of Moscow shown on the corresponding roll plot​

Level 3 Screening Results: Carried Forward

Key Findings 

 

  • Traffic Operations: Provides moderate congestion relief and improves east-west and north-south mobility. Performs well for regional travel times and travel time reliability.

  • Freight: The only alternative carried forward that provides a continuous freight route within Idaho.

  • Safety: Provides substantial safety benefits by separating traffic at high-speed locations and widening north of Moscow.

  • Property and Environmental Impacts: Has substantial property and environmental impacts.

  • Community Planning and Implementation: Has moderate implementation and phasing potential and some consistency with long-term community plans. Uses Palouse River Drive improvements being considered by others.

Result:

Alternative B is Carried Forward​ in Level 3. This alternative may be refined and considered for recommendation in the final PEL document.

alternative B map

Alternative C: Washington State Line 

Includes Rural Widening North of Moscow shown on the corresponding roll plot

Level 3 Screening Results: Carried Forward

Key Findings 

 

  • Traffic Operations: Provides the greatest reduction in total system delay and substantial downtown travel-time improvement.

  • Freight: Does not provide a continuous freight route in Idaho.

  • Safety: Provides substantial safety benefits by separating traffic at high-speed locations and widening north of Moscow.

  • Property and Environmental Impacts: Has substantial property and environmental impacts.

  • Community Planning and Implementation: Has high potential to be implemented, phased, or integrated with long-term community plans. Crosses into Washington, requiring interstate coordination.

Result:

Alternative C is Carried Forward​ in Level 3. This alternative may be refined and considered for recommendation in the final PEL document.

alternative C map

Alternative D: Airport Road Interchange 

Includes Rural Widening North of Moscow shown on the corresponding roll plot​

Level 3 Screening Results: Not Recommended

Key Findings 

 

  • Traffic Operations: Has the lowest reduction in total system delay of all the alternatives. Provides moderate congestion relief.

  • Freight: Does not provide a continuous freight route in Idaho.

  • Safety: Provides substantial safety benefits by separating traffic at high-speed locations and widening north of Moscow.

  • Property and Environmental Impacts: Has substantial property and environmental impacts.

  • Community Planning and Implementation: Provides a direct connection to the airport. The Airport Road interchange has a limited ability to be implemented, phased, or integrated with long-term community plans. Utilizes Palouse River Drive improvements that are under consideration by others.

Result:

Alternative D is Not Recommended​, which means it has fewer benefits when compared to other alternatives. The Mill Road connection to Palouse River Drive is being evaluated as a potential element for other alternatives.

Alternative D Map

Alternative E: Airport Road Partial Cloverleaf 

Includes Rural Widening North of Moscow shown on the corresponding roll plot

Level 3 Screening Results: Carried Forward

Key Findings 

 

  • Traffic Operations: Provides strong operational benefits reducing total system delay and downtown congestion. Improves both east-west and north-south mobility.

  • Freight:Does not provide a continuous freight route in Idaho.

  • Safety: Provides substantial safety benefits by separating traffic at high-speed locations and widening north of Moscow.

  • Property and Environmental Impacts: Has the greatest property and environmental impacts of the alternatives.

  • Community Planning and Implementation: Has moderate implementation and phasing potential and is consistent with some long-term community plans. Requires extensive new infrastructure.

Result:

Alternative E is Carried Forward​ in Level 3. This alternative may be refined with updates in the southeast quadrant.

Alternative E map

Level 3 Evaluation - Scoring

level 3 evaluation scoring table

Pinch to zoom

For more information about Level 3 scoring, please contact the study team

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