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I-84 Caldwell to Karcher

ITD is making plans to improve I-84 between Caldwell and the Karcher/Midland Interchange.

The traffic study and environmental analysis of the project is complete.
The Karcher Road (exit 33) in Nampa to Franklin Road (exit 29) in Caldwell portion has been approved for funding. Construction is expected to start in 2021.

The Centennial Way (exit 27) to Franklin Road (exit 29) in Caldwell portion has not yet been approved for funding.

El Departamento de transportación de Idaho está haciendo planes para mejorar el Interestatal 84 entre Caldwell y el intercambio de Karcher. El trabajo en esta área se encuentra en multiples etapas de estudio y diseño. Manténgase Informado: Para más información y para recibir una hoja de inforamación, por favor llame 208-334-8567

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Learn about design plans
between Franklin Road and Karcher/Midland Road
I-84

Environmental study and traffic analysis

The Idaho Transportation Department is evaluating improvements to Interstate 84 between Caldwell and Nampa. This is part of a plan to invest more than $300 million into I-84 in Canyon County over the next several years.

This project included a traffic study and environmental evaluation that is now complete. ITD considered potential impacts to adjacent properties, minority populations, noise, floodplains, wetlands and many other factors. Public input was a key element of the study.

The Caldwell to Karcher project has been divided into two parts:
> The Karcher Road (exit 33) in Nampa to Franklin Road (exit 29) in Caldwell portion has been approved for funding. Construction is expected to start in 2021.
> The Centennial Way (exit 27) to Franklin Road (exit 29) in Caldwell portion has not been approved for funding.

Planning for the future

ITD has developed long-term alternatives for improving the section of I-84 between Centennial Way and Franklin Road in Caldwell. These plans have not yet received funding.

Advancing design work (Caldwell to Nampa)

In 2018, the Federal Highway Administration accepted a proposal from ITD to complete the environmental study in smaller parts. This allowed ITD to move forward with designing improvements between Franklin Road and Karcher/Midland Road. This portion of the Caldwell to Karcher corridor has been funded.

ITD is designing an additional interstate lane in each direction between Franklin Road in Caldwell and Karcher/Midland in Nampa. To add lanes on I-84, the Middleton Overpass and Ustick Overpass must be replaced.

Construction began on the Middleton Road Overpass in August 2020. Work is expected to be completed by May 2021. Once the Middleton Road Overpass construction is complete, the Ustick Road Overpass construction will begin soon after.

Traffic study

Outcomes of the traffic study have helped ITD identify needed improvements and confirm how far west into Caldwell the improvements need to be made.

View Traffic Study Maps

Environmental evaluation

In compliance with the National Environmental Policy Act (NEPA), the environmental evaluation provided an environmental document and clearance for addressing the traffic needs on the interstate. The document evaluated potential improvements that will improve long-term mobility while minimizing impacts to the human and natural environment. The evaluation  considered potential impacts to adjacent properties, minority and low-income populations, noise, floodplains, wetlands, air quality and many other factors. Public input was an important part of the environmental study.

View Environmental Study Timeline

Funding

ITD has allocated more than $300 million in state, federal and GARVEE funds to improve I-84 in Canyon County. $150 million of this funding has been allocated to the section of I-84 between Caldwell and the Karcher Interchange in Nampa.

This funding will cover the environmental study and traffic analysis for the entire corridor. It also will cover design and construction between Franklin Road and Karcher/Midland. Additional funding will be needed to design and construct the improvements west of Franklin Road.

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