Highway 29 project to start in 2026, detours planned

Traffic on Central Wisconsin’s busiest highway will once again be reduced to just two lanes for much of 2026 as part of a multi-phase state project that will stretch roughly 13 miles through the heart of western Marathon County.

At a public hearing in Edgar last Thursday, officials from the Wisconsin Department of Transportation told residents about repaving and improvements planned on STH 29 that will span at least two construction seasons and run from CTH E South, west of the STH 97 interchange, to Purple Martin Lane east of Marathon City. Work will also be done on 3,700 feet of STH 97, requiring a shutdown of the exit and a detour route that has yet to be decided.

Replacement of the pavement and asphalt shoulders will take place exclusively on the westbound (north) lanes of the highway, with traffic being diverted to one lane in each direction on the eastbound (south) side of the highway. Just last year, a similar project was completed on the eastbound lanes of STH 29, from CTH E to CTH H north of Edgar.

The work will be divided into three sections, with crews moving east to west. The first section of the project will run from just west of Purple Martin Lane to just east of Pheasant Falls Road, followed by the second section from near Pheasant Falls Road to west of STH 97. A total of about eight miles will be affected during these first two sections.

The final stretch of the project, from a half-mile west of STH 29 to CTH E South, isn’t scheduled to take place until 2029, though it could be moved forward to an earlier year if funding becomes available.

“We’re going to have it ready so it could go in 2026, but as of right now it’s not,” said Korey Boehm, the DOT’s project manager.

Plans for all phases of the project are slated to be completed by August of 2025, with bids going out at the end of next year for the middle and eastern sections.

Engineer Robert Jack of Strand Associates, which has been hired by the DOT to design the plans, said the main goal of the project is to replace pavement that’s in bad shape. To illustrate his point, he displayed a picture of the rough terrain motorists are accustomed to driving on.

“Highway 29 is a backbone route in the state,” he said. “It moves large traffic volumes throughout the state, all the way from Green Bay to Eau Claire, so it’s a very important route.”

Jack said no major changes to the width or height of the roadway are planned, nor will any turn lanes or through lanes be added or subtracted “It’s more or less replacing the pavement that’s there with brand-new pavement,” he said, noting that the contractor will also be replacing several guardrails and culverts along the route.

In the middle section of the project, the STH 97 interchange and ramps will be reconstructed, and the pavement on STH 97 will be replaced from 2,500 feet south of STH 29 to 1,100 north of the interchange. The westbound entrance and exit ramps at the CTH H interchange north of Edgar will also be replaced in 2026, and the “porkchop” islands will be removed from the offramps, which will be shifted slightly to north and south to “provide a little more distance between that bridge and the off-ramp,” Jack said.

Two detour routes are being considered for when the STH 97 interchange is closed. Under the first option, traffic that would normally head north on STH 97 would go northbound on STH 13 at Colby/Abbotsford and then go east along STH 64 out of Medford. Southbound traffic would use STH 13 to get to STH 153 south of Unity and go east from there. Option 2 would divert traffic via STH 107 at Marathon City to either STH 64 or STH 153 going west.

The CTH H interchange will also be closed temporarily, but that will not happen at the same time as STH 97 is blocked off, Jack said.

“So, at one point or another, there’s always going to be an interchange that’s open,” Jack said.

In addition to the repaving, the DOT’s contractor will install deceleration lanes for westbound traffic exiting from STH 29 and acceleration lanes for westbound traffic entering STH 29.

“So, you’ll get your own lane for 600 feet before you have to taper in (merge) instead of the taper design that’s there today,” he said.

On the eastern section of the project, from east of Pheasant Hill Road to west of Purple Martin Drive, the contractor will be doing a seven-inch concrete overlay of the existing pavement.

Crossover points will be opened up at different points along the construction routes, and the contractor will be required to maintain access for local residents and businesses. If a driveway needs to be temporarily closed off, property owners will receive advance notice, the DOT says.

Road crews will be working the entire construction season, roughly from April to October, Jack said, and it may even spill into the next year.

Boehm said they’ve been asked by multiple people if the first two phases of the project could be moved up to next year, but he said 2026 is the earliest it could be scheduled. He acknowledged that STH 29 is a highpriority project based on how much wear and tear it gets.

“It does see a lot of truck traffic,” he said. “That’s one thing we noticed last year when we were reconstructing the eastbound side. It’s probably 20 to 30 percent truck traffic, so yes, it does see a lot of volume on the heavy side.”

In response to a question about a possible overpass being constructed at the CTH S intersection, Boehm said he’s not aware of any plans to do that. He also asked how long it will be before STH 29 is converted from an expressway to a freeway, which would mean the elimination of all intersections at ground level. He said he was unable to answer that question at this point, but he said those plans would take years to implement.

One resident who attended the hearing said wait times are getting longer for turning onto STH 29, and worried that it will take more traffic fatalities before the transition to a freeway is approved.

“It’s been called ‘Bloody 29’ for a reason,” he said.