I-15 Northgate to Blackfoot Widening

Southbound traffic shifted onto the lanes constructed in the median of I-15 in May 2026. The week of June 1, motorists can expect ramp closures, lane closures and changing traffic patterns.

• The southbound on-ramp at the Fort Hall Interchange (Exit 80) is expected to remain closed until Friday, June 12. Motorists can detour to the South Blackfoot Interchange (Exit 89). View a detour map.
• The southbound off-ramp at the Northgate Interchange (Exit 73) is expected to remain closed until Friday, June 12. Motorists can take I-86 to the Chubbuck Interchange (Exit 61) and use Yellowstone Avenue (US-91) and New Day Parkway to detour around the closure. View a detour map.
• Speed limits are reduced to 55 mph.

Spring 2026 Update

It’s time for another I-15 construction update!

Check out the video to learn the latest about upcoming work on the I-15 Northgate to Blackfoot Widening and Riverton Road Bridge projects.

Construction on I-15

Crews began work to widen I-15 between the Northgate Parkway and Fort Hall interchanges (exits 73 & 80) in September 2024. Construction is anticipated to be completed in 2027.  

ITD is widening I-15 to three lanes in each direction to improve safety, increase capacity and modernize aging infrastructure.

Improvements include:

• Improving bridges, overpasses and interchange structures.
• Widening I-15 to three lanes in each direction.
• Constructing a barrier wall in the median.

What’s happening now?

Crews have constructed the new lanes in the median, the median barrier wall and the northbound lanes on I-15. Southbound I-15 traffic is shifted into the new lanes in the median and crews are constructing the new southbound lanes of the interstate. Motorists can expect:

• Nighttime lane restrictions.
• Traffic shifts and lane changes.
• Reduced speed limits.
• Ramp work and changes at exits 73 and 80. Temporary ramps may be shorter than current ramps.