Motorists traveling southbound on Interstate 15 between Pocatello and Fort Hall should expect significant traffic changes beginning Sunday night, May 31, as construction crews advance the ongoing I-15 expansion project in the corridor.
The Idaho Transportation Department announced that southbound traffic will be redirected into newly constructed lanes running through the median near the Northgate and Fort Hall interchanges. The move is designed to allow work crews to press forward on building new southbound lanes and ramps as part of the larger freeway expansion effort.
Which Ramps Are Closing and for How Long
Two interchange ramps will be taken out of service for approximately two weeks as part of the traffic shift. The southbound off-ramp at the Northgate Interchange and the southbound on-ramp at the Fort Hall Interchange will both be closed during this period.
Drivers who would normally use the Fort Hall Interchange will be detoured south to the South Blackfoot Interchange instead. Those planning to exit at Northgate will need to take a longer route — using Interstate 86 to the Chubbuck Interchange, then navigating through New Day Parkway to reach their destination.
Reduced speed limits will also be in effect throughout the construction zone for the duration of the work. Transportation officials are urging drivers to stay alert, observe all posted signage, and reduce their speed when passing through the area.
Part of a Broader I-15 Expansion Effort
The ramp closures and lane shifts are components of an ongoing Interstate 15 widening and improvement project in the Pocatello region. The I-15 corridor through Bannock County and the surrounding area has long been a critical artery for commerce and commuters traveling between southern Idaho and points north and south along the Front Range of the Rocky Mountains.
Construction projects of this scale routinely involve multiple phases of lane shifts, ramp closures, and traffic pattern changes as crews work to build new infrastructure without shutting down the freeway entirely. The current traffic shift allows work to continue on infrastructure that will ultimately expand capacity and improve safety along one of southeast Idaho’s busiest stretches of highway.
Drivers commuting between Pocatello and Chubbuck who regularly use the Northgate Interchange should plan extra travel time and familiarize themselves with the alternate route via I-86 and New Day Parkway before the closure takes effect Sunday night. The detour adds mileage but keeps traffic moving through established surface streets in the Chubbuck area.
For those unfamiliar with the South Blackfoot Interchange detour for Fort Hall traffic, transportation officials recommend reviewing the posted signage in advance and allowing additional time, particularly for commercial truck drivers who may need to account for the extra distance on their routes.
Bannock County has seen a range of infrastructure activity in recent weeks. The City of Pocatello recently conducted smoke testing on its underground sewer and stormwater systems as part of separate municipal maintenance efforts.
What Comes Next
The two-week closure window means the Northgate and Fort Hall ramps could reopen by mid-June, depending on construction progress. The Idaho Transportation Department has not specified what phase of the I-15 expansion project follows the current lane shift, but motorists should anticipate that construction activity in the corridor will continue for some time as the broader project moves toward completion.
Drivers are encouraged to monitor the Idaho Transportation Department’s travel information resources for real-time updates on lane closures, detour routes, and any changes to the construction timeline. Remaining patient, reducing speed, and staying attentive in active work zones protects both drivers and the construction crews working along the interstate.
For additional statewide transportation and infrastructure news, visit Idaho News.