Northbound I-15 traffic between the Northgate and Fort Hall interchanges shifts this week

I-15 with construction being conducted on the new lanes between northbound and southbound lanes.

The Idaho Transportation Department will shift northbound Interstate 15 traffic between the Northgate and Fort Hall interchanges (Exits 73 and 80) the night of Wednesday, Nov. 12. Northbound traffic will move into the newly constructed lanes in the median to allow crews to begin work on the east side of I-15.

During the traffic shift, motorists can expect:

The northbound on-ramp at the Northgate Interchange (Exit 173) will close for a few hours on Wednesday night, Nov. 12.
Lane closures may occur in the project area.

After traffic is shifted, motorists can expect:

Two lanes will remain open in each direction on I-15 during the daytime.
A concrete barrier will separate opposing lanes of traffic.
Reduced speeds in the work zone.

Once the new northbound lanes are completed in late 2026, crews will complete the southbound lanes on the west side of I-15. Construction on the I-15 Northgate to Fort Hall widening project is anticipated to be completed in 2027. This project is funded by Governor Little’s Leading Idaho initiative and will result in three lanes in each direction on I-15.

For more information and to sign up for email or text updates visit itdprojects.idaho.gov/pages/i15northgatetoblackfoot or call 208-252-5553.

The safety of motorists and construction crews is ITD’s top priority during construction. When driving through the work zone, please stay alert, follow work zone signage and drive the posted speed limit. Drivers are encouraged to plan extra time when traveling through the project area and check 511.idaho.gov or the 511 mobile app for the latest updates on restrictions and delays.

28 hours to reopen I-15 after catastrophic bridge strike

A police officer stands below a pilar hanging loose from the overpass.

At approximately 8:45 p.m. Thursday October 30, an empty milk tanker traveling on Interstate 15 near Blackfoot, Idaho went off the road and struck a pillar of the Riverton Road Overpass. The crash nearly obliterated the cab of the Kenworth semitruck with the engine tumbling yards down the median. The northernmost supporting pier nearest to the southbound lanes was violently bent, pushed several feet, and broken by the catastrophic impact. Yards of guardrail and ties were ripped up, broken and tossed about the scene. The pier cap bent downward and cracked over the central pier.

The driver of the semi-truck was life-flighted to Eastern Idaho Regional Medical Center in critical condition where his identity and status have not been shared officially. Idaho State Police, local law enforcement, and ITD employees from the Blackfoot shed moved quickly to close traffic on both the northbound and southbound lanes as well as the overpass.

Immediately following the crash Engineer Manager II Zak Johnson and Operations Engineer Greydon Wright were called to the site to inspect the damage. District Engineer Todd Hubbard also left for the site shortly after. Initial photos from the scene were sobering, and the decision was made to keep both the northbound and southbound lanes of the interstate closed. State Bridge Engineer Mike Johnson in Boise received cell phone photos and confirmed that the wisest course of action was to close the interstate until he could arrive on Friday morning to inspect the damage.

With the interstate closed between Exit 89 and Exit 93, traffic was diverted on to U.S. Highway 91 including through the city of Blackfoot. With an average daily traffic count of more than 30,000 vehicles, traffic quickly began to back up on I-15, along US-91, and in the city of Blackfoot. Adding to the confusion, the ramps at Exit 89 are not signalized, causing long delays for drivers trying to turn left. Traffic flowed better at Exit 93 due to special light timing plans enabled by electricians Landon Larsen and Kamron Hatch. Additional traffic began spill over to alternate local roads as drivers tried to find their way around the massive traffic jam.

Word spread quickly throughout the community in large part due to photos shared late at night from operators out of the Blackfoot shed that showed the extent of the damage and helped the community to realize the importance of the closure of I-15. That post garnered nearly 500,000 impressions showing high interest in the community and across the state. Local media picked up the story from ITD’s Facebook page and ran the photos on their websites and on the morning news.

Friday morning, Hubbard requested cribbing material (wood posts) stored in the D4 yard to be sent to D5 to help with shoring up the bridge. A scissor lift was also ordered to be delivered from the Soda Springs shed to the crash site. Finally, a loader and an excavator were also brought in.

Johnson and Wright huddled down in Hubbard’s office to come up with a game plan. Soon young engineers were lurking at the doors of his office to listen in and learn. As Hubbard said later, “What an opportunity for these young engineers to learn, right? By watching closely what happens with this event they are better prepared for ten, fifteen, or twenty years down the road. When they see something similar unfold in the future, they’ll be able to say they had seen something like this before and know what steps to take.”

Meanwhile on I-15, morning commuter traffic north and south of Blackfoot began to back up again onto the freeways north and south of the city. City, county, state, and tribal law enforcement were stretched as they attempted to manage Halloween traffic.

District 5 alerted media that another update would be sent out in the afternoon after the bridge engineer had a chance to survey the damage. The first on-site interview with KIFI Channel 8 happened during their noon broadcast. At that time Hubbard, Wright, Zak Johnson, and Mike Johnson also arrived on-scene to fully inspect the damage. Cognizant of the teaching opportunity previously mentioned, a half dozen other engineers were also invited along.

Also on site were D5’s Paul Archibald and Darrell Hanners with a drone to take close-up photos of the damage for Mike Johnson to review. ISP also had a drone to 3D map the scene of the crash for their investigation.

The first concern to address was how likely it was for the bridge to have a catastrophic failure that would drop the deck on the interstate below. There was a possibility that if the central deck fell it could pull the eastern side of the roadway down with it, hence the full closure underneath the structure. With that later determined to be less of a concern, ITD had more options for how to restore traffic.

Key to restoring traffic on I-15 was the stabilization of the central and western portions of the bridge. A hasty meeting was held between the engineers, maintenance staff and local contractors Cannon Builders and Wadsworth Brothers. By 3 p.m. the group had finished their assessment and settled on the plan: stabilize the bridge by using concrete blocks, each 3,000 pounds with interlocking groves to keep them together, placed beside the piers.

ITD issued another update to the media and to the public to share the news that by mid- morning Saturday drivers could expect one lane of traffic in each direction to flow on the northbound lanes.

Cannon Builders worked long into the night, and at 12:46 a.m. State Comm sent out an alert that traffic was being allowed onto I-15 again. Two crossovers near the bridge were utilized to shift the southbound traffic on to the northbound segment and off again. Just 28 hours after the entire closure of I-15, traffic was moving again.

Monday morning Cannon Builders and A-Core Concrete specialists began removing the broken pier and part of the pier cap. Some shoring was moved into the southbound passing lane so southbound traffic could be allowed back on the driving lane. Riverton Road will not carry any traffic until repairs are complete, which likely won’t be until the spring.

Community interest remains high and is almost entirely positive. Altogether, Facebook stats show that more than 1.5 million views of posts about the closure. Morning, noon, and evening newscasts carried the story throughout the weekend as did the local newspaper.

Hubbard expressed his thanks to all involved: “This was truly a team effort with multiple districts, multiple sheds, and multiple law enforcement agencies working night and day to keep Idaho’s traffic moving on I-15. I couldn’t be happier with our response.”

I-15 traffic shift at Riverton Road

right hand lane of I-15 is open with a concrete divider protecting temporary pier supporting bridge.

The Idaho Transportation Department has shifted lanes to offer travelers one southbound lane and two northbound lanes separated by a median on Interstate 15 between Blackfoot Exit 89 and Exit 93. Traffic had previously been crossed over to the northbound lanes with little separation between oncoming traffic following a collision last week that badly damaged the Riverton Road Bridge.

ITD engineers estimate that southbound I-15 will remain one lane underneath the bridge and that the bridge itself will remain closed until next spring.

Motorists are encouraged to use 511.idaho.gov for the latest traffic conditions.

Pocatello Creek ramp closure scheduled for tomorrow

Beginning tomorrow at 9 a.m. the Pocatello Creek Road on-ramp to northbound Interstate 15 will be closed to allow crews to remove pavement and to prepare to pave the new on-ramp. The closure is expected to last until approximately 2 p.m. Detours will be in place to guide traffic to the Northgate Interchange or to the Clark Street Exit.

Cold weather paving in Idaho: how we do it and why it works

Paving, compacting and temperature testing occurring in Idaho with Fall leaves in the background.

The Idaho Transportation Department is overseeing more road construction than ever before. This work continues as temperatures are cooling and the ice and snow make their all-to-soon appearance. How does ITD successfully pave a road and have one of the shortest summer seasons in the country? Materials engineering and testing actually do make it possible.

Before asphalt pavement is ever laid, the surface where it needs to go is sprayed with a binder that will make it stick. This is called tack, a liquid made of oil and water. Tack must naturally break apart to become adhesive, separating as it lays across the surface where paving will happen. As it breaks, tack turns from a brown color to darker black, indicating that breaking has happened, and asphalt can be laid on top.

On the warmest of Idaho summer days, tack breaks in about ten minutes. When it’s colder, it can take hours. Still, with the right process, tack will break. ITD just knows it takes longer and plans accordingly.

Hot mixed asphalt is combined in a hot plant that can heat the components—crushed gravel and oil—to more than 300 degrees. This is dumped from a truck and spread using a paver, then compacted with a roller. ITD inspectors are on site anytime the contractor is, testing temperatures, compaction and much more to ensure that taxpayers get their money’s worth out of each project.

For quality compaction on state highways and interstates, the process must occur between 240-280 degrees. On warm summer days, asphalt must sit for a while after being spread before it is cool enough to be compacted. On colder days, asphalt loads hauled from hot plants are covered in transit to retain the most amount of heat. The asphalt will then be spread, and the roller follows closely behind to compact immediately before the material has cooled too much. All century-old, effective tricks of the trade in action.

“We don’t loosen up our requirements just because it gets cold,” ITD Materials Engineering Manager Mark Hayes said. “All contractors are held to the same quality materials standards and only operate when there are ways to do it right.”

Most of Idaho’s state highways run through rural areas, far removed from permanent hot plant locations. This fall, paving is occurring on State Highway 28 between Leadore and Salmon. The closest permanent hot plant sits in Idaho Falls, nearly four hours away. Enter the mobile hot plant erected by contractors at the ITD Leadore gravel pit, less than five miles from where the asphalt needs to be delivered.

In Rexburg, where paving is still occurring on multiple interchanges off U.S. Highway 20, the contractor’s permanent hot plant lies in Teton, less than ten miles away. Planning to have these proximities ensures that temperature requirements are met, and paving can be done successfully both earlier and later in the year.

Of course, there comes a cold enough ambient daily temperature that means paving operations are simply no longer viable. ITD requires that the temperature be 40 degrees and rising for paving to happen, which can result in fewer hours to pave during the fall but still allows a window of work. The right equipment, materials, planning, testing and operating tricks of the trade make it so ITD and contractors can pave with quality even when it is colder outside.

When you see paving equipment and a compacting roller working close together while your heater is on inside your car, know that ITD and the industry have the brief Idaho summers and cold Idaho temperatures on tap. That new road surface will meet the same metrics as summer paving, ensuring it lasts for many years to come.

The Unhailed, Underappreciated Emergency Responders

SH-33 with road blockades and a pickup truck following an accident

People see the Idaho Transportation Department logo and seem to have an automatic response, for better or worse. They’re the ones causing construction delays, needing to get the snow off the road already, or taking too long whatever they’re doing. They don’t do anything right and never will. Their flashing orange lights could just as easily be the mailman.

It’s not likely that you think of ITD as being the ones to first call 911, the ones to keep you from freezing or assess injury at the side of the road. They’re not your emergency responders. But then again, yes, they are.

All across Idaho, there is no one that travels the over 12,000 lane miles of highways and interstates more continually than the men and women behind the blue and orange ITD logo. The likelihood that they’ll be there when a crash or emergency occurs is higher than anyone else. The police and ambulance have to be called in. ITD is already there.

When two crop duster planes collided and crashed alongside US-26 near Arco, an ITD striping crew was there, becoming the first to assess the pilots. When a motorcycle crash occurred on Interstate 15 near Dubois, part of the ITD maintenance crew was there, already working the roads they consider their own. The story is similar in the case of many incidents across Idaho over the years.

“We spend so much time on the road, that nine times out of ten, we’re the first on scene when anything happens,” Idaho Falls area foreman Jared Loosli said. “And we’re not just going to pass by and leave.”

In the instance of a recent multi-fatality crash near the I-15/ US-20 interchange, Loosli and his crew were called in immediately to assist the Idaho State Police. Most people don’t realize that when state troopers get called out, ITD is almost always called out too.

“We have great foremen for ITD here in Idaho,” ISP Lieutenant Marvin Crane said. “We have personal relationships with them, and they never say they can’t do something. They’re always asking, ‘What do you need?’ and getting things done within minutes.”

“It does affect you,” Loosli stated, also noting that the worst incident he’s ever been a part of happened to one of his own guys.

“The first thing I’m thinking about is my crew,” Ashton/ Island Park foreman Ryan Wright added. “At that point, there are no traffic devices, there’s not time and it’s not the priority. It’s just our guy in the middle of everything trying to help.”

Very recently, Driggs/ St. Anthony Foreman Lucas Richins witnessed what all ITD foremen prioritize and fear the most. An ITD maintenance worker was hit after a distracted driver ran through a roadblock while powerline repair work was being done on SH-33.

So not only are ITD employees unhailed first responders, they’re also the underappreciated workers putting their lives on the line every day. Earlier this year, three of Loosli’s crew were removing hazards from I-15 when a semi grazed the side of their vehicle, damaging the rear end and taking off the driver’s side mirror. A mere two inches would’ve changed the outcome of that incident entirely.

What is it that keeps the guys in yellow working in these risky situations and responding to emergencies, knowing full well that public opinion is often negative and even rude?

“These are small communities,” Mackay/ Challis foreman Jeremy Johnson noted. “When we go out on a call, it could very well be our own friends and families. We’re thinking of keeping them safe in everything we do.”

“When I’m doing something myself, I can see the progress and know that I’m making things safer for everyone,” Wright shared. “I actually love to go out plowing. I love what I do.”

“It’s really a mentality,” Loosli says. “You either have it or you don’t honestly. People complain because they drive by and see four guys standing around. But we know why, we see the bigger picture and the process. The 30 seconds people see isn’t the story of the whole 10-hour day at all.”

“On instinct, I’m thinking about what I could have done, how could this have been prevented?” Richins said. “But then the biggest thought becomes frustration. We’re here trying to help and to serve. When we close a road, the whole point is to keep people safe. Driver awareness is so negligent that it really is frustrating. It’s dangerous.”

Adding to the dangerous nature of the job is the reality that the ITD fleet are not considered emergency vehicles, and ITD signage is too often not respected. Multiple layers of striped road blockades or orange traffic barrels somehow don’t always keep people out.

“We don’t enjoy closing a road or causing delays,” Richins emphasized. “We do it and we have to because it is the safest way. People need to be patient and have respect.”

“I don’t need to be liked,” Wright added. “I’m still here to do a job and to protect people.”

So maybe the next time you barely notice the flashing orange lights of an ITD vehicle alongside the road, want to scream in standstill construction traffic or at being stuck behind a plow, you’ll slow down and think too that those folks in bright yellow are also the ones who will be there before anyone else can. They could be the difference between freezing after sliding off the road or staying warm until the tow truck gets there. They could be the one to help make sure that your own family and friends across our tight-knit Idaho communities are given emergency support in time to matter.

It’s even highly likely that they will be.

Ramp closure scheduled at the System Interchange

Map of system interchange in Pocatello showing detour through Northgate Interchange.

Beginning tomorrow night, the northbound to westbound ramp of the Interstate 86/Interstate 15 System Interchange will be closed to allow for demolition of the old eastbound to northbound bridge. Traffic intending to travel westbound on Interstate 86 from northbound Interstate 15 will be detoured through the Northgate Interchange. Work will continue until Thursday when the ramp reopens at 7:30 a.m.

Originally built in the 1960s, this is the last existing bridge of the System Interchange that will need demolition as part of the $112 million redesign. The project is scheduled to be completed next summer.

Motorists should carefully follow signs and posted speed limits while traveling through the construction area. With crews working day and night, it is especially important that drivers be alert and proceed safely through the work zone.

Motorists are encouraged to use 511.idaho.gov or the 511 app to keep track of project detours. Project details are also available at itdprojects.idaho.gov/pages/i-86i-15-system-interchange

System Interchange weekend ramp closure begins tomorrow

Map showing System Interchange detour through Northgate

Beginning tomorrow at noon the eastbound Interstate 86 to southbound Interstate 15 ramp will be closed while crews construct a temporary road to the new eastbound to southbound ramp. Eastbound traffic on I-86 looking to travel south on I-15 will be detoured north through the Northgate Interchange (Exit 73). The closed ramp will reopen late Sunday.

This work will allow the eastbound lanes to be adjusted to the grade of the new ramp. Doing the work this weekend will limit traffic impacts during the peak Labor Day weekend.

Originally built in the 1960s, the I-86 and I-15 System Interchange is undergoing $112 million of redesign work to improve safety and replace aging infrastructure. The project is scheduled to be completed next summer.

Motorists should carefully follow signs and posted speed limits while traveling through the construction area. With crews working day and night at the System Interchange it is especially important that drivers be alert and proceed safely through the work area.

Motorists are encouraged to use 511.idaho.gov or the 511 app to keep track of project detours. Project details are available here on ITD’s projects website.

Variable speed limit signs in place in the I-84 South Jerome to Twin Falls work zone to improve safety

JEROME – The Idaho Transportation Department (ITD) has installed variable speed limit signs to improve safety as crews widen I-84 between the South Jerome and Twin Falls Interchanges. The new signs are controlled remotely, allowing ITD to lower speeds when crews are working near traffic.

The current posted speed limit in the work zone is 70 mph. When crews are working near traffic, ITD will lower the speed limit, and a flashing beacon will notify drivers that speed limits have been lowered. When crews are not as close to traffic, ITD will raise the speed limits to 70 mph.

Variable speeds have been successfully implemented in other work zones, including the one on I-84 between Caldwell and Nampa. Research shows that variable speed limits reduce crashes, reduce travel times, and improve safety.

The signs will be removed when construction is complete in late fall of 2025.

Details about the I-84 South Jerome to Twin Falls project are available at ITDProjects.org/84jerometotwin or by texting 84JTF to 1-866-483-8422.

Rolling Closures on I-84 from South Jerome to Twin Falls through mid-July

The Idaho Transportation Department is continuing work on I-84 between the South Jerome (Exit 168) and Twin Falls (Exit 173) Interchanges. Crews are blasting rock in the median of I-84 on weekday afternoons through mid-July.

What you need to know:

Rolling closures will occur on I-84 through mid-July.
Delays will range from 20-30 minutes.

A pilot car will slow motorists down several miles before the blast area to allow crews to blast rock and clean up debris.

Details about the I-84 South Jerome to Twin Falls project are available at ITDProjects.org/84jerometotwin or by texting 84JTF to 1-866-483-8422.