Public comment sought on I-15/Siphon Road Interchange project

I-15 Sign

POCATELLO – The public is invited to submit input via an online comment portal on the proposed Interstate 15/Siphon Road Interchange project. The project is currently being developed, with construction starting as early as 2018.

The interchange will be built approximately three-quarters of a mile north of the Chubbuck Road overpass (milepost 73.5) in Bannock County.

The public comment portal can be found at:

The portal includes a comment form and map featuring the preliminary design of the proposed interchange and its local connector roads. Additionally, it allows users to view a listing of all submitted comments.

The I-15/Siphon Road Interchange project includes the construction of a bridge over I-15 with interstate highway entrance/exit ramps. Any new local roads connecting the existing local-road network to the new interchange will be built by local entities prior to the completion of the new interchange.

The need for the interchange arises from the following issues:

– Limited existing access to I-15 north of the I-15/I-86 junction causes out-of-direction travel that contributes to congestion on U.S. 91 (Yellowstone Avenue)

– Limited existing access to I-15 north of the I-15/I-86 junction is not expected to accommodate the area’s projected future growth northeast of Pocatello and Chubbuck in Bannock County

– Crash rates on U.S. 91 and I-15 in the Pocatello/Chubbuck area exceed statewide averages

Since the previous public outreach for the I-15/Siphon Road Interchange project was concluded more than five years ago, the transportation department will provide an update on the project and invite the public to submit comments on the proposed interchange layout.

Comments are being accepted through July 31. They can be e-mailed to, or to Comments also can be mailed to: Idaho Transportation Department, Attn: Adam Rush, 3311 W. State Street, Boise, ID  83703.

Those with questions about the project can contact Adam Rush at (208) 334-8119, or Greydon Wright at (208) 239-3317.

For questions or comments regarding the construction of the new local connector roads outside interstate right-of-way, please contact the city of Chubbuck, city of Pocatello, or Bannock County.