Interstate 35, the most traveled north-south corridor linking Des Moines with communities across Iowa and beyond, is undergoing a massive transformation between Ankeny and Huxley.

The $163.6 million project is in the midst of reconstructing 9 miles of interstate, widening the roadway from four to six lanes, and replacing five aging bridges, including adding two new interchanges in an effort to improve safety and accommodate the heavy traffic volumes that make this stretch one of the region’s most critical routes.

The multi-year project, which started in 2023 with an anticipated completion date in 2027, is being performed by heavy civil contractor C.J. Moyna & Sons of Elkader, Iowa. Together, the Iowa Department of Transportation (Iowa DOT) and C.J. Moyna & Sons’ crews are tackling a complex series of phased rebuilds designed to keep traffic flowing while remaking the backbone of central Iowa’s interstate network.

“It’s a heavily traveled corridor, with a mix of commuter, freight, and agricultural traffic,” said Dustin Skogerboe, Resident Construction Engineer with Iowa DOT. “Keeping vehicles moving safely while rebuilding bridges and pavement is one of our biggest challenges.”

The bridges and pavement between Ankeny’s 36th Street interchange and the 315th Street bridge in Huxley had simply reached the end of their service lives. Skogerboe noted that cracking, spalling, and settlement in the existing pavement made for a rough ride, and several of the overpasses had become functionally obsolete.

“Traffic has grown dramatically here, and the four lanes just weren’t enough,” he said. “By adding a third lane in each direction, we’re improving capacity, reliability, and safety for decades to come.”

The improvements also reflect Iowa DOT’s emphasis on community identity in that each of the new bridges will incorporate elements of the Monarch Highway theme, a nod to the I-35 corridor’s role as a migratory pathway for monarch butterflies. The design not only adds visual appeal but also ties the engineering work to the natural landscape.

Being so heavily traveled, keeping I-35 open during construction was non-negotiable. To accomplish that, Iowa DOT and C.J. Moyna & Sons mapped out a phased approach spanning five construction seasons, with each stage building on the last while keeping traffic moving.

“This corridor sees tens of thousands of vehicles every day, so we had to break the job into logical phases,” said Ryan Kipp, Project Manager with C.J. Moyna & Sons. “We’re basically rebuilding a live interstate one half at a time, and that takes a lot of planning and coordination.”

When work began two years ago, the first step was replacing the Elkhart interchange bridge and constructing a new southbound pavement stretching from 36th Street north to NW 134th Avenue. This early phase set the foundation for the larger effort, giving crews space to shift traffic and prepare for heavier bridge work ahead.

In 2024, attention shifted north with the addition of a new 315th Street bridge in Huxley and the replacement of the Heart of Iowa Nature Trail bridge with a culvert beneath I-35. Road work also took place on the southbound lanes between NW 134th Avenue and NW 150th Avenue, further extending the new pavement northward.

This year is bringing two of the project’s most visible changes: a new interchange at Iowa 210 in Huxley and a new bridge at NW 158th Avenue. C.J. Moyna & Sons is also reconstructing the remaining stretch of southbound I-35 north of NW 150th Avenue, pushing the upgraded pavement all the way to the project’s northern limits.

For 2026 and 2027, the job will focus on the northbound lanes, Kipp said.

“Once traffic is shifted onto the new southbound pavement, crews will return to the start of the corridor and rebuild the entire northbound side, completing the transformation of this 9-mile stretch of interstate,” he said.

The project is not without its challenges. Most notably, working in the middle of Iowa’s busiest interstate requires great emphasis on traffic control, so barrier placement, signage, and crossovers must be properly maintained while large sections of pavement and bridge deck are in the middle of demolition.

“Every phase requires us to think two or three steps ahead,” Kipp said. “When you’re shifting traffic onto new pavement while tearing out old bridges, there’s no margin for error.”

Drainage has also been an issue, as Iowa’s heavy spring rains can overwhelm work zones if stormwater is not carefully managed.

“Water is always the enemy in road construction,” Kipp said. “We’ve had to build temporary controls and adjust schedules around weather to keep the site stable.”

Additionally, phasing bridge replacements presented some difficulties of their own, with Kipp explaining that at the 315th Street site, crews had to coordinate demolition and new substructure work while maintaining access for local traffic and minimizing disruption to nearby farmland.

A demanding project like this required some savvy ideas. For instance, C.J. Moyna & Sons deployed stringless paving guided by GPS, ensuring smoother surfaces and tighter tolerances than traditional methods. The team also used drones to fly over the corridor regularly to survey grades, monitor progress, and document conditions.

The new roadway is also being built with a layered pavement section designed for durability, where crews place a cement-treated base below thick Portland cement concrete to handle the pounding of heavy truck traffic.

“These design elements mean this pavement should last far longer and perform better under today’s freight volumes,” Skogerboe said.

The bridge construction also balances aesthetics and performance, with precast girders accelerating installation and decorative elements reflecting the Monarch Highway theme to create a distinct visual identity. For the Heart of Iowa Trail crossing, engineers opted for a culvert solution rather than a new bridge, reducing long-term maintenance and providing a safer, more durable trail underpass.

The I-35 rebuild requires significant manpower and equipment so C.J. Moyna has pulled in crews from across Iowa, supplemented by union support and subcontractors specializing in concrete, steel, and traffic control.

Equipment on site has included fleets of Caterpillar excavators and dozers, GOMACO concrete pavers, and John Deere graders. Trucks haul in aggregate and remove demolition debris daily, often under tight time windows dictated by traffic flow.

“Central Iowa has seen a lot of roadwork recently, and keeping up with material and trucking demand has been a challenge,” Kipp said. “But our team has worked hard to stay ahead of supply issues.”

With live interstate traffic flowing through the job site, safety is always top of mind.

“Our workers are inches away from 70-mile-per-hour traffic,” Skogerboe said. “Protecting them while also protecting drivers requires strict protocols and continuous monitoring.”

To limit issues, C.J. Moyna & Sons’ crews work nights and weekends to perform lane shifts and demolition during off-peak hours. Strict work zone protocols include attenuator trucks, barrier walls, and constant flagging operations.

On the public side, Iowa DOT has made communication a cornerstone. The agency provides online updates, detour maps, and social media alerts, helping drivers anticipate delays and plan alternate routes.

“We know construction is disruptive, so we’ve tried to be proactive in telling people what’s happening and why,” Skogerboe said. “That transparency helps build patience and understanding.”

The strong collaboration and communication between Iowa DOT and C.J. Moyna & Sons has also been key to the project’s success.

“There are always surprises when you’re rebuilding infrastructure of this scale,” Kipp said. “The DOT has been responsive when we’ve needed quick decisions, and that’s kept us on schedule.”

When completed in 2027, the Ankeny-to-Huxley corridor of I-35 will look entirely different, as it will be a modern six-lane interstate with new bridges, improved interchanges, and safer, smoother pavement.

Skogerboe noted the investment is expected to ease congestion, improve freight movement, and enhance safety for decades.

“This isn’t just about replacing old pavement; it’s about building a stronger connection for Iowa’s economy and its communities,” he said.

For C.J. Moyna & Sons, the project has been a proving ground for innovation and teamwork.

“Every big highway job teaches you something new,” Kipp said. “On I-35, we’re learning how to combine advanced technology with careful phasing to rebuild a critical corridor while keeping it open. That’s knowledge we’ll carry to the next project.”

• Owner: Iowa Department of Transportation
• General Contractor: C.J. Moyna & Sons, Elkader, Iowa
• Engineer: Iowa DOT Design and Marshalltown Resident Construction Office
• Other Contractors: Progressive Structures LLC, Flynn Company Inc., Grimes Asphalt and Paving Corp., United Contractors Inc., Voltmer Inc., Taylor Fencing LLC, Dave Gryp Construction Inc., Abaci Consulting, Absolute Group, Iowa Plains Signing Inc., Gus Construction, Jenco Construction Inc., The Driller LLC, Manatt's Inc., Lindner Painting, OEL Construction Services Inc., Henricksen Contracting LLC, Iron Works Inc.