The Montana Department of Transportation is planning major upgrades to the Gore Hill and I-15 interchange in Great Falls.
MDT says growth in the area — including an growing airport, business growth and more residents — is driving the need for improvements. The project will add two single-lane roundabouts at the 31st Street Southwest and I-15 on and off ramps.
A third lane will also be added on the I-15 southbound lane between the 10th Avenue exit and the airport exit.
Additional improvements include a wider bridge deck, a new pedestrian walkway and the relocation of Tri-Hill Frontage Road.
Great Falls MDT District Administrator Jim Wingerter said roundabouts reduce fatal crashes by 90% and increase mobility by 60 to 70%.
"There's no stopping there. Traffic is moving. We keep traffic moving through our roundabouts and it reduces that stop and go traffic. And if there are collisions they're usually sideswipe collisions and not 90-degree collisions. Reduces the severity of those collisions," Wingerter said.
MDT says the project will cost around $31.8 million. Construction is expected to begin in the summer of 2027.
FROM MDT: PROJECT BACKGROUND
In 2015, MDT developed the I-15 Gore Hill to Emerson Junction Corridor Planning Study in partnership with the Federal Highway Administration (FHWA) and the Great Falls Metropolitan Planning Organization.
The study identified safety and operational concerns, and recommended improvement options to address the transportation needs within the corridor through 2035.
Among these improvement options were the addition of a southbound auxiliary lane between the Gore Hill and 10th Avenue South interchanges, and intersection improvements at the Gore Hill Interchange.
The Great Falls Long Range Transportation Plan (LRTP) 2018 Update also included recommendations to make improvements to the Gore Hill Interchange as outlined in the Corridor Planning Study.
The 2015 I-15 Gore Hill to Emerson Junction Corridor Planning Study and 2018 Great Falls Long Range Transportation Plan identified several safety and operational concerns at the Gore Hill Interchange.
Transportation issues and concerns included:
- Congestion and safety concerns due to high traffic volumes, especially during peak hours, and close intersection spacing.
- Limitations in current intersection designs to handle increasing airport, truck stop and other commercial truck traffic volumes.
- Merging conflicts with truck traffic on I-15 due to the short distance between the 10th Avenue South Interchange and the Gore Hill Interchange.
