Plans are currently underway to improve the I-15 South Blackfoot Interchange (Exit 89).

The Idaho Department of Transportation has begun the planning process to improve the South Blackfoot Interchange at Exit 89. The South Blackfoot Interchange has served motorists since 1961. Since then, the population and traffic volumes in eastern Idaho have increased significantly.

At this intersection, Interstate 15 crosses US Highway 91 in the Fort Hall Reservation. The interchange is located in an area of ​​I-15 that is heavily used for business, residential and leisure travel. To improve safety and mobility for motorists, it is necessary for ITD to replace the interchange with a design that has increased capacity and meets current standards.

Project plans currently include:

• Extension of ramps to improve safety.
• Adding a dedicated exit lane to the exit ramps to improve ramp operations.
• Adjusting the interchange to accommodate future additional lanes on I-15.

Improvements to this transportation hub will be developed and designed based on traffic and other technical data, an environmental assessment, research and public input. The planning, design and environmental assessment phases of the project are expected to be completed in 2026. Construction of the improvements is expected to begin in 2030, pending the availability of additional funding. This project utilizes both state and federal funding.

ITD will offer multiple opportunities for the public to learn more about the I-15 South Blackfoot Interchange project throughout project development, including a public open house and pop-up meetings in early 2025. For more information, visit the project website at itdprojects.idaho. gov/pages/i-15-corridor or call 208-252-5553.