Could high-speed beltways one day encircle the Boise area? ITD wants to know
AI-generated summary reviewed by our newsroom.
- ITD plans to study possible corridors to ease future congestion in Treasure Valley.
- Two potential beltway routes south of Kuna and north of Middleton under review.
- Planners will assess feasibility based on projected growth, terrain and infrastructure.
Treasure Valley drivers: Consider how long your daily commute takes on Interstate 84. Now, imagine adding half that time to it.
That’s the grim reality that state and regional transportation planners foresee by the time the Valley has surpassed 1 million residents in 2050. Without big changes, drivers will face 50% longer commutes by then, projects the Community Planning Association of Southwest Idaho, or Compass, on the Interstate and beyond.
What to do? Historically, the Idaho Transportation Department has dealt with traffic on I-84 largely by adding lanes. In the 2000s, the state expanded the freeway from two to four lanes in each direction between Boise and Nampa, the first lane additions since the road was built in the 1960s. A series of interchange upgrades and overpass widenings have followed, along with the addition of a third lane further west into Caldwell, some of which is ongoing.
But the roadway is inching closer to the full buildout possible under its original right-of-ways. ITD is considering spending $100 million to widen the corridor to five lanes, but that’s as wide as the road could go without bumping into other properties, according to Mark Wasdahl, ITD’s planner for District 3, which covers Southwest Idaho.
Wasdahl told the Idaho Statesman that state highway officials are now looking for the Treasure Valley’s “next big step forward for transportation.” Those discussions have surfaced a few areas “of interest” for possible new high-speed corridors beyond the Interstate, the ITD planner said.
Now, ITD is working with Compass to examine two possible routes that could give drivers another option for fast east-west travel.
ITD to conduct $320K study on southern Ada County beltway
First on ITD’s study list: a possible beltway running east-west to the south of Kuna, state highway officials and regional planners told the Statesman.
The scope of the study is from Idaho 45 in Nampa to the Blacks Creek Interchange at I-84 in Boise, Wasdahl said. It would look at extending Kuna-Mora Road into a high-speed roadway. It would also examine whether north-south roads could be extended south to Kuna-Mora to provide additional “connections.” Those roads could include Idaho 69, also known as Meridian Road, and the new Idaho 16 extension, he said.
Wasdahl emphasized how preliminary the study is and said the extensions are “hypothetical.”
“All of this is travel demand modeling,” he said, “which means it’s not really lines on a map. It’s lines on a whiteboard.”
Vincent Trimboli, an ITD District 3 deputy administrator, said the study aims to determine: “If you went two miles south of Kuna and you went east and you went west, what would be possible from a roadway perspective? And a lot of things are possible, but are they really, truly feasible?”
Trimboli added that the study would also try to determine factors such as how many lanes would be needed, how the route would navigate geographical challenges including canal crossings, and whether it would be managed by ITD as a state highway or by a local highway district as a local road.
The transportation department in September geared up to sign a $320,000 contract with Boise consulting firm Kittelson and Associates for the study, according to Aaron Bauges, the department’s District 3 planning manager.
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Growth brings beltway conversation to the table — again
Bauges noted that for his entire career with ITD, nearing 30 years, the Kuna-Mora route has been a topic of conversation.
When asked what precipitated the study now, Bauges pointed to a map. “If you look ... at Kuna, it’s exploding. As Southern Ada County is pushing further south, as Nampa is growing both south and east toward Boise, and Meridian’s in-filling, this provides an opportunity for any one of those communities to ... have a parallel route to the Interstate system to go east and west as they see fit.”
Growth in the Treasure Valley’s eastern stretches, including the $15 billion Micron expansion in Southeast Boise, has also made the possible east-west corridor desirable, Bauges said.
In an interview with the Statesman, Kuna’s Mayor Joe Stear also emphasized how long there have been talks of extending Kuna-Mora, though he said planning agencies previously considered a bypass “to reduce the traffic on I-84 that actually runs through Boise,” especially for trucks.
But Bauges said ITD’s goal now is not to bypass the Interstate or allow traffic to skip past Boise. “Because the reality is, a lot of the Interstate traffic is headed to downtown Boise,” including freight, he said.
“A lot of other large cities have what they call beltways,” he said, highways that encircle an urban area and in some cities even look like a ring. “This is kind of what we would call our own beltway within the system that allows other local traffic to circulate within the Treasure Valley as a whole.”
Within the city of Kuna, an east-west corridor could help spur economic development, according to Stear. Kuna-Mora runs through the city’s industrial area, he said. “The problem we’ve always had with economic development and bringing businesses to Kuna is we don’t have a freeway running through us ... So people don’t happen to just drive through, generally.”
A high-speed route, he said, “Would kind of help open that up.”
In the near-term, Stear added, the city is focused on getting Idaho 69 extended further south, which would provide some “desperately needed” traffic improvements including an overpass crossing the railroad tracks south of Indian Creek.
‘Mid-Star Northern Highway’ also source of planning interest
An second beltway conversation is happening in the northern stretches of the Treasure Valley, on the border of Ada and Canyon counties.
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“Much like going south of Kuna, there’s been a long-talked-about opportunity that people have discussed going from the Interstate north of Middleton and going to the east back toward State Highway 16,” said Trimboli.
ITD, in partnership with cities of Middleton, Eagle and Caldwell, as well as Highway District 4 and Canyon County, put in a “member service request” with Compass for the planning agency to study the area, Trimboli said.
Trimboli rattled off some questions the study would aim to answer. “One, would you need a road, and how wide that road might be? And you know, what would you do to both plan and potentially fund it?”
The study itself is not yet funded but has been identified as “needed” in Compass’s long-range plan, according to Compass spokesperson Amy Luft.
Luft said by email that the study would “identify possible triggers, such as forecasted demand, congestion/travel time, or growth within the area” to “help determine what and when to take the next logical steps such as additional and more in-depth analyses.”
In April, Star Mayor Trevor Chadwick told the Statesman that he believes the Idaho 16 extension, which is expected to open in 2027, will spur more growth in his and surrounding cities in the northern Treasure Valley.
“It will become necessary for ITD leadership to work with the communities of Star and Middleton to plan for a new northern highway that will connect Interstate 84, northwest of Middleton, to Highway 16 northeast of Star,” he said by email. He said he plans to call it “the Mid-Star Northern Highway.”
This story was originally published October 3, 2025 at 4:00 AM.
