ID-55 Construction Transitions to Summer Schedule in Coming Weeks

excavator on road

Starting May 17, road closures on ID-55 between Smiths Ferry and the Rainbow Bridge will shift to a new schedule: Monday through Thursday, 12 – 2 p.m. Please note that opening times may change due to unforeseen circumstances, such as equipment, weather and daily blasting results. Outside of the closure window, the road will be one-way alternating traffic with a 15-minute delay. This will continue through May 27, the end of the spring schedule.

For Memorial Day weekend, Friday, May 28, through Monday, May 31, the road will be fully open to two-way traffic.

The summer schedule will start Tuesday, June 1. ID-55 will be reduced to one-lane alternating traffic Monday through early Friday and then will be fully open to two-way traffic through Sunday. This schedule will be in place through early September.

Visit for more information or to sign up for email and text alerts, or call (833) 913-ID55 to speak to a project representative

Overnight closure on I-84 between Eagle Road and I-184 Monday for utility work

Interstate 84 will be closed between Eagle Road and I-184 (The Connector) for three hours overnight Monday, May 10th to allow Idaho Power crews to work over the roadway.

Idaho Power will be stringing new power lines adjacent to Cloverdale Road. To safely work over I-84, the utility company will install a net over the highway. The installation will require daytime work on the shoulder. Then, from 1 a.m. to 4 a.m. on May 10th, I-84 will be closed as crews erect the netting.

During the closure, I-84 traffic will be diverted to local roads. Eastbound traffic will exit at Eagle Road (Exit 46), travel along Overland Road, and re-enter the Interstate at Cole/Overland (Exit 50). Westbound I-84 and I-184 traffic will be detoured at Cole/Overland and Franklin Road (Exit 1) respectively. They will travel on Franklin Road and re-enter the Interstate at Eagle Road.

Detour route for cloverdale Road overpass closure

The Ada County Highway District will be actively managing signal timing on Overland and Franklin Roads during the closure to maximize the efficiency of those routes. ITD recommends the traveling public plan trips around the closure time or anticipate significant delays through the closure area.

Idaho Power estimates placing the new lines will take 8-10 days. A second closure of the Interstate will be required when that work is complete to remove the netting.

For questions about Idaho Power’s project, contact Sven Berg, Idaho Power Corporate Communications Specialist, at or (208) 388-2905.

Northside Boulevard Interchange at Interstate 84 will fully open on Sunday morning (May 9)

Northside SPUI nearly complete

The Northside Boulevard interchange will be fully opened to motorists on Sunday morning, May 9 at 6 a.m. ITD began construction on the interchange in July 2019 and will reopen on schedule.

The Northside Boulevard Interchange has been replaced with a Single-Point Urban Interchange or SPUI design to accommodate more traffic and reduce delays.

The new SPUI interchange includes:

  • A central traffic signal underneath I-84 that will direct all turning movements from a single point.
  • New sidewalks and bicycle lanes added to both sides of Northside Boulevard.
  • Flattened on- and off-ramps to improve visibility for vehicles accessing I-84.
  • New ADA curb ramps at the intersection of 6th Street and Northside Boulevard.

features of the new Northside SPUI

ITD will open the new lanes of I-84 between Karcher Interchange and Franklin Boulevard on Tuesday morning, May 11. Motorists will have three lanes in each direction and a new auxiliary lane between the ramps.

“ITD would like to thank the community for their patience during the construction of this important project,” said Mark Campbell, ITD Project Manager. “Heads up, there are still final cleanup activities in the area over the next few weeks as construction crews finish the project. We ask motorists to continue to slow down and pay attention in the work zone.”

To request text message updates about other major traffic impacts on I-84 in Canyon County, text 84CORRIDOR to 1-866-ITD-84CC. For details about the I-84 expansion in Canyon County, visit or listen to the monthly Drive Idaho podcast.

Reconstruction of Middleton Road Bridge over Interstate 84 complete, open to traffic

The Middleton overpass is nearly complete

The Idaho Transportation Department has completed the reconstruction of the Middleton Road Bridge over Interstate 84 ahead of schedule and will open it to the public tonight. ITD will cover the opening at 8 p.m. live on Facebook.

The reconstruction was necessary to make room for additional travel lanes for I-84. ITD has begun the first phase of constructing a third travel lane in each direction. The new Middleton Road Bridge is long enough that a future fourth lane can be constructed without conflict.

The bridge was rebuilt ahead of schedule by contractor Concrete Placing Company. The cost of construction was $5.5 million.

The new bridge features a travel lane in each direction, wider shoulders, and a sidewalk on the north side. The design allows for future expansion of Middleton Road without the need to rebuild the entire structure. The project also constructed a signal at the intersection of Middleton Road and Cherry Lane, north of I-84.

“This project went really well and this new bridge is a great investment for transportation in the area,” said ITD Project Manager Michael Lucas. “We had a lot of coordination with some local road projects and the work on the Interstate. The crews worked through Covid-19 complications, adverse weather, and a lot of night work to get the job done. I appreciate the public’s patience during construction.”

The Department will quickly move to the second bridge over I-84 restricting the widening, Ustick Road. That bridge lies a little over a mile to the west of the Middleton Road Bridge. The Ustick Road bridge reconstruction project requires two separate bridge structures to be rebuilt, one over I-84 and the other crossing the Notus Canal. ITD will release a timeline for that project at a later date. Current information on the Ustick Road Overpass project can be found online at

I-84 Safety Service Patrol continues through the I-84 work zone to Caldwell

New signage on a patrol truck for the I-84 work zone

The Idaho Transportation Department launched the next phase of a safety patrol and courtesy towing service on Interstate 84 this week. The service, which was introduced in 2019 in Nampa, will now include the I-84 construction zones in Caldwell.

The Safety Services Patrol provides complimentary towing for disabled vehicles in the I-84 construction zone. The service has assisted 274 vehicles since it began.

“I-84 is the main commuting and freight route for thousands of drivers in Canyon County,” said Mark Campbell, ITD project manager. “Our goal in funding this service is to keep these drivers moving as safely and efficiently as possible as construction moves west toward Caldwell.”

Patrol vehicles will operate Monday-Friday from 6 a.m. to 9 a.m. and from 3 p.m. to 7 p.m. between 10th Ave/City Center (exit 29) and Karcher/Midland Road (exit 33). Vehicles will be marked with new signage to increase visibility.

Disabled cars, trucks or motorcycles are towed to one of four locations located on the map. Motorists are responsible to arrange transportation for their vehicle within 24 hours.

“We are committed to continuing the close working relationship between this program, our state communications office and Idaho State Police in the next phase of the program,” said Campbell. “These offices, working together, are able to clear crashes quickly and safely.”

Crews recently began constructing temporary travel lanes in the outside shoulders of I-84 between Caldwell and Nampa. For more information about I-84 construction in Canyon County, listen to the Drive Idaho podcast or visit

Eastbound lanes to close tonight on Chinden at the Linder intersection

Graphic of the closure of Chinden at Linder

As part of ongoing construction to widen Chinden in the Treasure Valley, several eastbound lanes on Chinden will close tonight at the Linder intersection and stay closed until construction on this segment ends later this summer.

Flaggers will reduce eastbound Chinden to one dedicated left turn lane and one through/right turn lane so crews can place traffic signal poles. Westbound traffic will not be affected, but eastbound motorists should expect significant delays at peak travel time and allow extra time to reach their destinations.

Download a graphic of the closure.

This configuration will remain in place until later this summer when work on this segment is anticipated to end. At that time, Chinden will open to four lanes, two in each direction, with a center median between Linder and Meridian Road.

To learn more about other widening plans in the corridor and sign up for updates, visit

Rockslide on ID-55 near Smiths Ferry

Rocks Hit highway

Final Update: 9:45 a.m. 4/9/2021

Debrief of slide and slope stability

In the wake of a rockslide on March 15 along Idaho State Highway 55 near Smiths Ferry, the Idaho Transportation Department has determined the slide was a localized event and, after additional mitigation, the greater hillside remains stable.

The slide occurred within a work zone where crews are cutting into the adjacent hillside to create extra room for ID-55 and enhance the overall safety of the road. The space will be used to reduce the severity of curves, construct wider shoulders, and add guardrail and pullouts.

Water from melting snow seeped into and destabilized the hillside at a cut crews created last fall. To prevent future localized slides, ITD is enhancing the reinforcement of the hillside as cuts are created. The Department has hired geotechnical experts to aid in this effort. This approach is expected to improve reliability of the hillside’s stability and the overall efficiency of the blasting work.

“Safety is the top priority of the Idaho Transportation Department. We are thankful no one was hurt during the rockslide activity on State Highway 55 last month,” said District 3 Administrator Caleb Lakey. “Hillsides and slopes become more unstable when doing work of this nature. We expect rock fall as a part of these projects. We had precautions in place to protect the traveling public in case of any slide activity and are doubling down on those precautions.”

ID-55 is now open to a single lane of alternating one-way traffic. Travelers should plan for a fifteen-minute delay at the project location. From now until late May, there will be daily closures Monday through Thursday from 10 a.m. – 2 p.m. to allow blasting and debris removal activity.

“I appreciate the public’s patience as we responded to this rockslide,” said Lakey. “We did not take the reduction of service on this critical corridor lightly. It’s a good reminder to drive attentive and be on the lookout for rocks on the roadway during the springtime.”

The project is anticipated to continue through Fall 2022. For more information, visit

update #12: 6:00 a.m. 4/2/2021

Spring Construction Schedule Resumes Today!

ID-55 is open to one lane of alternating traffic between Smiths Ferry and Rainbow Bridge starting at 8 a.m. today. Drivers can expect full road closures Monday-Thursday from 10 a.m. to 2 p.m. and one-way alternating traffic with a 15-minute delay when the road is not closed.

To sign up for email updates and text alerts, visit

update #11: 3:50 p.m. 3/31/2021

Idaho Highway 55 near Smiths Ferry will reopen to the public beginning at 8 a.m. Friday morning to a one-lane alternating traffic configuration. The highway will remain in this configuration except for regular closures Monday through Thursday from 10 a.m. to 2 p.m. as construction crews blast. Until Friday, the highway will remain closed, with an open window tomorrow from 8 a.m. to 3 p.m.

“We know how important it is to have the highway open for this weekend’s traffic,” said Caleb Lakey, ITD District 3 Engineer. “The response to the March 15 rock slide has been excellent, with many experts converging to address the problem quickly. I appreciate the public’s patience during this reduction in highway service.”

Sunday’s blasting work successfully mitigated travel risk in the area of the rockslide on ID-55 and experts feel confident that the hillside is now stable for safe, long-term travel through the corridor. Crews will finish removing the blast debris and cleaning up the area on Thursday.

From April 2 through mid-May, the road will be closed Monday through Thursday from 10 a.m. to 2 p.m., and open to one lane of alternating traffic with a 15-minute delay outside of the closure hours. For more information about the ID-55 Smiths Ferry Project, please visit

update #10: 2:00 p.m. 3/29/2021

Over the weekend, Idaho Transportation Department contractors successfully removed an undercut outcropping of rock that remained from a rockslide near Smiths Ferry on March 15, completing a critical safety intervention to allow a return to normal work.

Rock blasting

The outcropping presented a considerable safety hazard to the public using Idaho Highway 55 below. ITD brought in a nationally-recognized team of geotechnical engineers to assess the situation and develop a blasting plan to remove the remaining material. The blast occurred Sunday at 4 p.m. after the road was closed for the day.

“It was a picture-perfect blast,” said ITD Project Manager Alex Deduck. “We needed to remove roughly 1500 tons of material sitting 30-50 feet above the roadway. The narrow landing area made this incredibly difficult, but the team did a great job.”

The blast required several days of preparation. A survey crew scaled across the rock face to determine drilling locations. Then, a blasting plan was drawn up. On Saturday, an excavator and drilling machine were flown above the rock face to drill holes and set charges.

“The use of a helicopter was cheaper and faster for us,” said Deduck. “The terrain here is steep and covered in trees. It would have taken several days to pioneer a path to the slide location.”

The blast area is now under a 48-hour observation period to watch for additional movement. Following that, the blasted material will be removed. The road will remain closed except from 8 a.m. to 3 p.m. every day, when a single lane of alternating traffic will be allowed. ITD encourages motorists to us U.S. 95 as an alternate route.

ITD will provide another update this Wednesday evening.

update #9: 8:30 a.m. 3/26/2021

Idaho Highway 55 continues to be open daily to one lane of alternating traffic between 8 a.m. and 3 p.m. Travelers can expect a 15-minute delay during this time and road closures outside of these hours.

The current traffic restrictions are expected to last through early April as crews work to remove the remaining rock outcropping. Drivers are encouraged to plan ahead, visit Idaho 511, and pay close attention to the message boards on ID-55.

Update #8: 2:00 p.m. 3/23/2021

Geotechnical crew scaling the rockface
Geo-technical crew scaling the rock face Monday

Starting Wednesday, March 24, Idaho Highway 55 will have daily openings to one lane of alternating traffic from 8 a.m. to 3 p.m. The road will be closed outside these hours. Travelers can expect at least 15 minute delays during this time. Crews will be actively monitoring the rock outcropping and are prepared to close the road immediately if weather or hillside conditions change. ITD recommends travelers, especially large vehicles, RVs, and trucks pulling trailers, still use U.S. 95 as the alternate route.

“We want to thank the public for their patience as we respond to this rock slide,” said Caleb Lakey, ITD District Engineer. “Our ITD personnel and contractor crews have worked nights and weekends to open the road and protect the public. While this is a major milestone, we recognize that there is still significant effort required to resolve this issue.”

ITD is working alongside national slide experts and finalizing plans to safely remove the remaining rock outcropping, which will require additional full road closures. These closures will likely begin in the next seven days. More information about the closures will be provided as it is available. Drivers are encouraged to plan ahead, visit Idaho 511, and pay close attention to the message boards on ID-55.

Update #7: 5:30 p.m. 3/21/2021

landslide next to highway with survey crew
A crew surveys the slide area on ID-55

ITD has been monitoring the rock slide throughout the weekend and determined that conditions continue to be unsafe in the area, and Idaho Highway 55 will remain closed to traffic.

“At this point, our ITD team can’t confidently open the road with the existing risks to the traveling public and crews,” said Caleb Lakey, ITD District Engineer. “Recent weather conditions paired with the weakened hillside, rock and soil from the slide has created a situation that requires further considerations before we can allow cars through. We know ID-55 is an important travel corridor in Idaho and we are working hard to open the road safely.”

Drivers are advised to use U.S. 95 as an alternate route. The next update will be provided in the afternoon on Tuesday, March 23.

Update #6: 1:50 p.m. 3/18/2021

A national rock slide expert has evaluated the slide that took place March 15 on Idaho Highway 55 and determined that the road should remain closed at least through Sunday, March 21 for safety reasons. ITD is working diligently to safely open the road to traffic and will monitor conditions through the weekend during the forecasted storms.  Working with experts, ITD will review conditions in advance of next week and provide another update during the afternoon on Sunday, March 21, so travelers can make appropriate travel plans.

“Safety of the traveling public, as well as the crews who are on site, is our top priority,” said Jason Brinkman, ITD District 3 Engineering Manager. “These decisions are not taken lightly. We understand that this road closure is not ideal, and are working extensively to reopen the road as soon as safely feasible.”

ITD continues to advise motorists to use U.S. 95 as an alternate route.

Panoramic photo of the slide, March 17th, 2021

update #5: 1:00 p.m. 3/17/2021

Idaho Highway 55 will remain closed today, through tomorrow. The Department continues to advise motorists to use U.S. 95 as an alternate route.

ITD crews monitoring the slide have seen continued movement of the hillside. The Department has called in nationwide experts to better assess the situation. These experts have assisted ITD in the past with the 2020 slide on U.S. 95 near Riggins. They will be on site tomorrow where we will asses how to proceed.

ITD will provide another update midday Thursday, March 18th.

update #4: 10:00 p.m. 3/16/2021

ID-55 near Smiths Ferry will remain closed due to the condition of the adjacent hillside. Safety is the top priority as crews continue to investigate the situation and work to reopen the road. Drivers shoulduse U.S. 95 as an alternate route. A status update will be provided midday Wednesday, March 17.

Update #3: 12:45 p.m. 3/16/2021

Crews are removing debris from the rockslide and working to open a single lane for travel. At this time, the closure will be extended beyond 2:00 p.m. today. Conditions are variable and no estimate can be given if the highway will open today or tomorrow. Motorists are encouraged to consider an alternate route.

Geotechnical engineers have conducted a preliminary assessment and believe there is risk more rocks may slide. Current work is focused on creating protection for at least a single travel lane on the highway from additional rockfall.

ITD has coordinated with emergency service providers to ensure critical services remain available for the community.

UPDATE #2: 11:25 A.m. 3/16/2021

Photo Gallery of slide added

update #1: 10:40 A.m. 3/16/2021

Idaho Highway 55 will remain closed while crews address the rockslide. The current plan is to follow closure protocols established for the highway project during a blasting event, which requires a complete closure from 10 a.m. to 2 p.m.

The slide removed rock and earth from beneath a spire on the hillside. The stability of that spire is uncertain and the area is considered dangerous. Motorists planning to travel between Valley County and Boise County should consider alternate routes.

Another update will be provided this afternoon.

Original post: 9:30 a.m. 3/16/2021

Late in the night on March 15th, a rockslide hit Idaho Highway 55 near Smiths Ferry, closing the highway. This is located within the work zone for the Smiths Ferry to Rainbow Bridge highway improvement project. However, at this time, there is no indication the work there directly triggered the slide.

There are no known injuries at this time. An excavator being used for the project did get hit.

Geotechnical experts are evaluating the situation. Given early observations at first light, the situation remains dangerous and the highway will remain closed.

“The rock and earth in this area is historically unstable,” said project manager Alex Deduck. “We saw a significant slide in 2019 just south of here. Last night’s slide is another example why our project is so important.”

The Smiths Ferry to Rainbow Bridge project will remove thousands of tons of rock and earth from the adjacent hillside to widen the highway, create rock catchment ditches, and reduce the severity of curves. Information about the project, as well as resources to sign up for email and text alerts, can be found at

More information will be posted on this blog post as the situation develops.

Eagle Rd. and Idaho Highway 44 (ID-44) intersection design reconfigured to traditional, signalized intersection

conventional intersection design for eagle road and idaho highway 44

The Idaho Transportation Department (ITD) is changing construction plans with a revised final lane configuration for the Eagle Rd. and Idaho Highway 44 intersection to build and upgraded traditional, signalized intersection with additional turn and through lanes in Eagle.

When complete this fall, the revised lane configuration will eliminate displaced left turn movements and potential wrong way driver confusion factors while still greatly relieving congestion during peak commute hours. The new Eagle Rd. and ID-44 design will include additional left-turning lanes and will replace short free free-running right turns with longer right turn pockets.

“After taking another look at the intersection design from a traffic operations layout and safety standpoint, we believe a wider, traditional lanes upgraded signalized intersection is the best solution that will benefit the Eagle community and region for 20 years or more at Idaho State Highway 44 and Eagle Road,” said ITD Chief Operations Officer Dan McElhinney.

Changes to construction will be seamless and will happen under the existing agreement with Knife River, the contractor. Elimination of the free-running rights allows the revised lane configuration to fit within the same footprint of the existing intersection and ITD anticipates the project will be built for around the same budget.  Every effort will be made to maintain the schedule with construction completed by fall 2021.

Motorists are encouraged to slow down and pay attention when traveling in the work zone.

To sign up for construction updates, visit

Full road closures on ID-55 Smiths Ferry project begin March 15

Spring construction picks back up on Idaho Highway 55 between Smiths Ferry and the Rainbow Bridge Monday, March 15. The Idaho Transportation Department’s project will widen shoulders, add guardrail, and straighten this curvy one-mile stretch of highway to improve safety. Watch the video below to see the project.


Earlier this month, crews removed snow and set up construction equipment in the canyon. Starting March 15, travelers should plan for full road closures Monday through Thursday from 10 a.m. to 2 p.m., due to controlled rock blasting needed to widen the road. When ID-55 is not closed, there will be one-way alternating traffic with 15-minute delays. This work schedule is expected through May, when crews will transition into summer operations.

To stay up to date and learn more, visit the project website


Construction of innovative intersection redesign at Eagle Rd. and Idaho Highway 44 (ID-44) begins next week

graphic of half CFI

The Idaho Transportation Department will begin construction of a half continuous flow intersection (CFI) at Eagle Road and ID-44 in Eagle on Monday, February 22 to improve mobility and safety at this busy intersection

Connecting two major highways in the Treasure Valley, more than 70,000 vehicles travel through this intersection every day. The half CFI design improves safety and reduces congestion all within relatively small footprint.

Across the nation, CFIs have a proven track record of increased efficiency and safety. This will be the first CFI constructed in Idaho. ITD encourages the public to learn how to navigate through the intersection by watching and sharing an explainer video below.

“The new design does require drivers to pay attention and think ahead, especially on Idaho Highway 44,” said Tyler Coy, ITD Project Manager. “I encourage everyone to learn more about how it works by watching the video during and after construction. When we’re done, there will be overhead signs guiding traffic to the right place. It’s really important people drive attentively.”

Due to traffic volume during the day, most construction will occur overnight between 10 p.m. and 6 a.m. Some work is scheduled during daytime hours but will mostly occur in the roadway shoulders. Nearby businesses and residents may experience loud noise from construction equipment, vibration, and bright light from the work zone.

Motorists are encouraged to slow down and pay attention when traveling in the work zone.

Construction is expected to be complete in early fall 2021.

The total project budget is $8.9M. Knife River is the contractor for construction.

To sign up for construction updates, visit To reach the project team, please email