Overview
The project begins approximately one mile north of the South Blackfoot Interchange (Exit 89) and ends approximately one mile south of the US-26/Blackfoot Interchange (Exit 93). The new design will prioritize safety, mobility and capacity to meet eastern Idaho’s growing transportation needs. The design of this project is expected to be completed in early 2027.
We’re back with another I-15 update!
Are you curious about what’s being planned for I-15 between Fort Hall and Blackfoot? Check out the fall update video to learn about the status of three design projects:
- I-15 South Blackfoot Interchange (Exit 89)
- I-15 Exit 89 to Exit 93 Widening
- I-15 US-26/Blackfoot Interchange (Exit 93)
Project details
The Idaho Transportation Department is developing plans to:
- Widen I-15 to at least three lanes in each direction.
- Replace the Riverton Road Overpass.
- Replace the I-15 Blackfoot River Bridge.
- Design a smooth transition between the design of this project and the South Blackfoot Interchange (Exit 89) and US-26/Blackfoot Interchange (Exit 93) projects.
Improvements are being designed using an environmental evaluation, traffic and other technical data, surveying and public input.
Background
I-15 was constructed in the 1960s and 1970s. In recent years, eastern Idaho’s population and traffic volumes have greatly increased.
For this reasons, it is necessary to develop a design that will increase capacity and mobility, improve safety and update I-15 to meet current design standards.
Anticipated growth
Eastern Idaho’s traffic volumes have greatly increased since the construction of I-15, and growth in the area is expected to continue. The Average Daily Traffic (ADT) count on this stretch of I-15 is expected to almost double by 2051. ITD plans to design an interstate that will serve the growing needs of eastern Idaho for years to come.
2023 – 27,500 ADT
2051 – 53,230 ADT
Project coordination
Several projects are being designed and constructed on I-15 between Pocatello and Blackfoot. Plans for each of these projects are being coordinated to maintain safety and mobility for motorists.
Timeline
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2025
Gather technical information to help develop preliminary design plans
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2025-2026
Develop preliminary design plans
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2026-2027
Develop final design plans
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2027
Construction begins if funds become available.
Frequently Asked Question
Increased traffic volumes on I-15 at Blackfoot warrant widening the Interstate to three lanes in each direction.
This project is utilizing state and federal funding. Elements of this project are funded with Transportation Expansion and Congestion Mitigation (TECM) funds as a part of the Leading Idaho initiative. TECM allows ITD to accelerate project timelines to address rapid growth and build critical infrastructure today in eastern Idaho that would otherwise take many years to fund and build. For more information on TECM funding, visit https://itd.idaho.gov/funding/tecm/.
An environmental evaluation is a process that helps the project team determine how design options will impact the human and natural environment around the project area. The data collected during this environmental evaluation will inform the project team as they work to develop a design that balances the needs of the environment with the public’s need for a transportation system that prioritizes safety, mobility and capacity.
Construction is expected to begin in 2027. This timeline may change due to the availability of funding.
The Shoshone-Bannock Tribes are a key stakeholder in this project, and ITD will provide them with project information and opportunities to share input during the design process.
Bridges & Overpasses
ITD will develop a design to replace the Riverton Road Overpass. The current overpass is a five-span bridge that is not compatible with widening I-15 into the median or the shoulder of the roadway. The new bridge design will accommodate a widened interstate. The project team also plans to increase bridge clearance to 23’ to accommodate mega loads on I-15.
ITD will develop a design to replace the I-15 bridges over the Blackfoot River. The current bridges are two lanes wide and will not accommodate a third lane. The project team will develop bridge structures wide enough for three lanes in each direction plus shoulders on each side.
Stay informed
Input from the community is important to the success of this project. ITD will provide multiple opportunities for public input during the design process. To remain informed about upcoming opportunities, learn more or provide feedback:
- Click here to sign up for email updates.
- Call (208) 252-5553
- Email info@pocatellotoidahofalls.org