Construction underway on State Highway 21 widening project in Boise

The Idaho Transportation Department (ITD) has started construction to widen State Highway 21 between Technology Way and Surprise Way in Boise.

The project began Monday, May 16 and is expected to finish in late July. Planned improvements include a new center turn lane, wider shoulders, and dedicated right turn lanes at the intersections of Grand Forest Drive, Lake Forest Drive, Old Oregon Trail Road, and Surprise Way. An acceleration lane will also be installed for traffic turning onto southbound SH-21 from Surprise Way. When complete, this stretch of highway will feature two 12-foot wide travel lanes, a 14-foot center turn lane, and 6-foot shoulders.

Construction will begin on the south side of the highway. When paving is done, traffic will shift to the new pavement as crews complete paving on the north side of the road.

The anticipated work schedule is Monday through Friday, 7 a.m. to 7 p.m., with work pausing on Memorial Day, Independence Day, and July 5.

Motorists should plan for reduced speeds through the construction zone, traffic shifts, and periodic delays with flaggers directing traffic. Access will be maintained to all neighborhoods throughout the project. ITD and the Idaho State Police urge motorists to slow down and pay attention when driving in work zones, where increased speeding fines and other penalties apply. Please plan ahead and visit for information on the state highway or interstate system.

For more information and project updates, visit

Bridge replacement underway on State Highway 46 in Gooding County

Map of Big Wood River Detour on SH-46

Work began earlier this week to replace the bridge over Big Wood River at milepost 112.9 on State Highway 46 north of Gooding. Built in 1947, the current structure has reached the end of its service life.

“We will raise the height of the new bridge approximately 3.5 feet,” ITD Project Manager Tom Logan said. “The additional height will allow for more flood water to pass underneath the structure.”

The new bridge will also be both wider and longer to increase mobility and safety.

Initial work will first include setup of traffic control and then demolition of a portion of the old bridge. While work is underway, traffic will be reduced to a single lane. Temporary traffic signals will be in place to direct motorists throughout the duration of the project.

“Drivers can anticipate wait times between two and five minutes when traveling through the area,” Logan stated. “Lane width will also be restricted to 12 foot during construction, and we advise motorists to plan ahead and use caution while traveling through the work zone.”

Short-term closures of SH-46 will also be required for different portions of the project to allow for crews to safely complete various stages of work. When these closures occur, signs will be in place to direct motorists through a detour route. Approximately four closures are anticipated throughout construction.

Cannon Builders of Idaho are the primary contractor on this replacement project that is expected to be complete this fall.

Public invited to review alternatives for US-20 improvements from Ashton to Idaho State Highway 87

RIGBY — The Idaho Transportation Department (ITD) will host two public meetings to share information about its Planning and Environmental Linkages (PEL) study and alternatives examining ways to modernize, improve safety, and reduce congestion on US-20 between Ashton and the SH-87 junction. ITD intends to adopt the findings of the PEL study into a future federal environmental clearance process.

The purpose of these meetings is to share alternatives developed from public workshops and the results of the screening committee. ITD will gather public comment on alternatives moving forward including concerns about environmental impacts. Information on access management strategies and opportunities for multi-use crossings along the corridor will also be shared. The public has two opportunities to participate. Both meetings will share the same information.

May 25, 2022,
5 p.m. – 7 p.m.
Island Park EMS Building
4378 County Circle
Island Park, ID 83429

May 26, 2022
5 p.m. – 7 p.m.
Ashton Community Center and Library
925 Main Street
Ashton, ID 83420

Increasing traffic is causing congestion and crashes. Improvements are needed to maintain a safe roadway, meet driver expectations, and provide a reliable connection to adjacent communities, Yellowstone National Park, and the region.

Using technical data and input gathered at public meetings in October and December 2021, the project team developed dozens of alternatives that have been evaluated against a range of criteria, including safety, capacity, and environmental impacts to identify the most promising alternatives for additional consideration.

Both meetings will be held in an open house format. Please stop by any time from 5 p.m. to 7 p.m.

For those who can’t attend in person, an online meeting will be available from May 26 through June 9 at

The comment period will remain open until June 9, 2022.

Public open house planned May 24 for US-20/26 Chinden West corridor improvements

The Idaho Transportation Department (ITD) invites the public to learn more about the future widening of U.S. Highway 20/26 between Middleton Road and Star Road.

ITD will host an open house on Tuesday, May 24 to share preliminary design plans and gather feedback on proposed improvements to this heavily traveled section of US-20/26.

This project will widen the highway and improve intersections to enhance safety and mobility for all users of the transportation system, including nearby residents, businesses, commuters, and freight carriers.

The public is encouraged to attend the drop-in style open house, share input on the plans, and meet members of the project team.

Tuesday, May 24, 2022
5-7 p.m.
Middleton United Methodist Church
104 E. Main Street (State Highway 44)
Middleton, ID

All materials provided at the open house will also be available online at beginning May 25, for those who can’t attend in person. Comments will be accepted through June 7.

The design of this project is funded with Transportation Expansion and Congestion Mitigation (TECM) funds as part of the Leading Idaho TECM Program. The program allows ITD to accelerate project timelines to address Idaho’s rapid growth and build critical infrastructure today that would otherwise take many years to fund and build. Funding for the next phase of work will be determined when the project progresses to that stage.

To learn more about the project and sign up for email updates, visit

Paving to begin next week on SH-75 project in Blaine County

Image of State Highway 75 north of Hailey

Work will resume next week on State Highway 75 north of Hailey. This is the final stage of a highway resurfacing project that has been underway since March of this year that will extend the life of the roadway and improve the driving experience for motorists.

“On Monday, we are planning to start paving work at Ohio Gulch Road and move south along the highway to Buttercup Road,” ITD Project Manager Brock Dillé explained. “Once that portion of roadway is complete, we will continue operations south but will need to detour traffic to safely complete the work.”

When work south of Buttercup Road occurs, daytime traffic traveling northbound on SH-75 will be detoured from McKercher Boulevard to Buttercup Road. The detour is expected to begin on Thursday (May 19) and last for approximately two weeks.

“Ours crews will not work during the Memorial Day weekend to allow for heavier traffic to flow more smoothly through the region,” stated Dillé.

Once paving operations are complete, striping will occur. At the intersection of SH-75 and Ohio Gulch Road/Starweather Drive, a new lane configuration will be implemented to better accommodate traffic flow. No other striping changes will occur within the project limits.

Motorists are advised to slow down, watch for workers and follow traffic signs when traveling through the work zone.

Western Construction is the primary contractor on this project that is expected to be complete in early June.

Public invited to attend open house for US-93 improvements in Twin Falls

Photo of Blue Lakes and Fillmore Intersection in Twin Falls

Members of the public are invited to learn more about upcoming construction plans that are scheduled to begin this spring on U.S. Highway 93 (Blue Lakes Boulevard) in Twin Falls.

Next Thursday (May 19), the Idaho Transportation Department (ITD) will host a public meeting and an online meeting to share plans about construction that will occur over the coming months on Blue Lakes Boulevard from the Perrine Bridge to Pole Line Road.

The project includes replacing the pavement, upgrading pedestrian ramps to ADA (Americans with Disabilities Act) standards, and replacing the traffic signal at the Blue Lakes Boulevard and Fillmore Street/Bridgeview Boulevard intersection.

The meeting will be hosted in a drop-in, open house format. Members of the project team will be on hand to answer questions and share information about construction plans and impacts.

Date: Thursday, May 19, 2022
Time: 5 p.m. – 7 p.m.
Location: Twin Falls High School
1615 Filer Ave. E, Twin Falls

For individuals unable to attend the in-person meeting, please join the self-guided online meeting beginning May 20 at An online comment form will be available for questions and comments.

To learn more about the project and sign up for construction updates, please visit the project website at

As part of Governor Brad Little’s “Leading Idaho” initiative, the 2021 Idaho Legislature dedicated $126 million of one-time funds from Idaho’s budget surplus to transportation projects statewide. The funds were split 60/40 between ITD and local jurisdictions. Construction on the Blue Lakes project is paid for with ITD’s portion of the funds that will accelerate projects to replace bridges, restore pavements, and improve mobility in communities across Idaho.

US-95 White Bird Grade fully open after rockfall

Railroad containers set in place to shield traffic

May 11 update:

All lanes on U.S. Highway 95 are now open after the Idaho Transportation Department removed debris from a rockfall on Monday morning and placed barriers to protect drivers.

One lane had remained open immediately following the rockfall. New railroad containers have taken the place of concrete rail to offer better protection should more rocks come down.

An excavator scoops up freshly fallen rocks on US-95
An excavator scoops up freshly fallen rocks on US-95

“More rocks fell down this morning. The slope is not stable,” Operations Engineer Jared Hopkins said. “This will not be a quick fix.”

The department is working to secure an emergency contract to further assess conditions and then likely use specialized equipment to scale the slope. Scaling involves knocking down loose debris proactively.

May 9 update:

Rockfall on US-95 blocks one lane on White Bird Grade
Rockfall on US-95 blocks one lane on White Bird Grade

Following persistent rain over the last week, a rockfall blocked lanes this morning on U.S. Highway 95 at the top of White Bird Grade south of Grangeville. The highway remains reduced to one lane.

Rocks ranging from 6 inches to 6 feet wide blocked the southbound lane around 10 a.m. Crews immediately responded by alternating northbound and southbound traffic and hauling away debris.

Rocks continued to fall down the slope, prompting the Idaho Transportation Department to place concrete rail to protect drivers. A spotter will watch the hillside through the night, ready to close the highway at a moment’s notice. Flaggers will control traffic through tonight and likely tomorrow night.

“This happened during blue skies,” Operations Engineer Jared Hopkins said. “Just a reminder that sometimes it takes a bit for rain to seep into a slope and make it unstable.”

Experts will continue to monitor the site. The department is arranging for large railroad containers to be placed at the edge of the highway to block any future rockfall.

“We will let this settle overnight, but in the morning our goal is to continue removing debris,” Hopkins said. “Once larger barriers are in place, we’re hopeful to have one lane in each direction while we identify a long-term solution.”

The department is also working to secure an emergency contract to use specialized equipment to scale the slope, a process that involves knocking down loose debris proactively.

Drivers are encouraged to monitor road conditions at

ITD Preparing Projects on I-86 Through Power County

AMERICAN FALLS – The Idaho Transportation Department is beginning the summer work schedule with several projects in the I-86 corridor through Power County. These projects include repairing the Rockland Exit 36 bridge, repairing the Sunbeam and Seagull Bay bridges, and a pavement preservation project along I-86 through Power County.

The Rockland Interchange repair is scheduled to begin in June and will consist of surface repairs, girder repairs, and the installation of a new waterproof membrane for the deck. Motorists should expect some delays.

The Sunbeam and Seagull Bay bridge repairs are scheduled to begin in early August. Both will undergo surface repairs and new concrete overlays. During construction, traffic will be moved to one side of the interstate via crossovers and slowed through the construction area. Motorists should expect some detours during this project.

The pavement preservation project will consist of a micro-seal application which is intended to extend the lifespan of the pavement. ITD currently plans to perform this work after the bridge repair projects are completed. The micro-seal application is scheduled to be completed by the end of September. During work there will be lane closures and reduced speeds in work zones.

Drivers are encouraged to check or the 511 app for the latest updates on construction and road conditions.

Blasting begins tomorrow on US-95 south of Culdesac

Truck passes through Culdesac Canyon

Update as of May 11: The blast has been rescheduled for next week. Up to three blasts are expected in the next two weeks, with each lasting up to one hour. 

The first blast of the season is expected to close U.S. Highway 95 south of Culdesac for up to one hour starting 6 p.m. on Wednesday.

Blasting this spring will make room for a new passing lane for southbound drivers. Blasts will generally be timed to avoid peak travel times and require a one-hour closure.

“We are expecting more blasting this month, but the schedule will be sporadic,” Resident Engineer Curtis Arnzen said. “Generally, there will be less blasting this year compared to previous work in the canyon.”

Construction this year will add 2.3 miles of passing lane and is part of a series of projects to add an 11-mile passing lane in Culdesac Canyon.

Crews will also replace the culvert for Rock Creek. For most of construction, drivers can expect all existing lanes to remain open. The contractor may reduce the highway to one lane at night.

Download a corridor fact sheet.

Drivers should pay attention to signs in the work zone to learn about the timing of the next blast or check Work is scheduled to end by early November.


I-90 nighttime lane closures planned between Post Falls and CDA for widening study

Traffic congestion I-90 near Huetter

Nighttime lane closures on I-90 over the next two months will collect data for a study to widen Interstate 90 between the Washington state line and Sherman Avenue in Coeur d’Alene.

Crews will focus on the section between Spokane Street and Northwest Boulevard, closing either a shoulder or lane in one direction at a time. Work will be done at night between 7 p.m. and 5 a.m., with the first closure scheduled for tomorrow night.

“The closure will move along the stretch as work progresses, spanning approximately one-quarter to one-half mile in length at any given time,” ITD Project Manager Erika Bowen said.

Drivers are asked to be aware of closures, to slow down and move to the open lane.

With traffic conditions congested now and volumes expected to double by 2045, ITD is studying I-90 from the Washington state line to Coeur d’Alene to identify improvements, modernize the system, reduce crashes and save drivers’ time. The study will evaluate needs and identify potential solutions like additional lanes and reconfigured interchanges to improve safety, capacity and mobility for current and future travel demands.

The work requiring this lane closure will investigate the pavement and foundations along the stretch using radar, drilling and other technologies to determine current surface conditions and the ability of the soil to support any potential new structures.

“Right now, we are collecting data to identify which improvements are needed and expect to bring options to the public this September,” Bowen said.

To learn more about the study and sign up for future updates, visit 

This study is funded with Transportation Expansion and Congestion Mitigation (TECM) funds. This deliberate investment of Leading Idaho TECM funds allows ITD to accelerate project timelines to address rapid growth and build critical infrastructure in the CDA area that would otherwise take many years to build.