More than 25,000 vehicles cross the Portage Lake Lift Bridge daily, making it one of Michigan’s most critical transportation corridors. That volume is more than double the traffic on the Mighty Mac. The Michigan Department of Transportation must carefully plan a major reconstruction project that will replace the bridge’s lift span, the section that raises and lowers to allow ships to pass through the canal.
The project represents one of the largest infrastructure undertakings MDOT has managed in recent years, and the department is taking an unconventional approach to ensure success.
The Lift Bridge Span Replacement
MDOT will choose between two distinct methods to replace the lift span, each with different implications for the community. The decision hinges on balancing construction efficiency against traffic disruption.
The first option involves replacing components of the lift span piece by piece over multiple winters while the span remains in place. This method would be less invasive to daily commutes but would require extended work periods.
“This would have most likely required multiple winters of single-lane closures on the bridge,” said Dan Weingarten, communications manager for MDOT’s Superior Region. “A lot of this work needs to be done when the shipping season is not underway and the bridge doesn’t have to raise and lower periodically.”
The second option, and potentially faster approach, would involve constructing the new span off-site and floating it into place using barges, the same method used when the bridge was originally built.
“That entire central span, which I believe is 260 some feet and four and a half million pounds, would be floated into place with barges,” Weingarten said. “Obviously that’s a huge undertaking, but it’s something that we believe could be completed quickly and it would be less of an impact to traffic.”
However, the floating method would cause major disruption to traffic for the entire Keweenaw Peninsula during the operation.
MDOT selected Zenith Tech, a Wisconsin-based bridge engineering firm with previous experience on the lift bridge, to help navigate these complex decisions. The department is using a Construction Manager/General Contractor (CM/GC) process, a newer approach for large public infrastructure projects that allows multiple planning aspects to happen simultaneously.
“This isn’t just a concrete and steel structure that stands there and is the same all the time. It’s a moving complex machine,” Weingarten said of the Portage Lake Lift Bridge. “This approach has some advantages, especially when you’re dealing with something as complex as this bridge.”
This collaborative approach allows engineers to identify solutions early and test multiple options before finalizing plans. Weingarten noted that the process should result in “a smoother process so things can be vetted in advance and we can find solutions early on.”
Timeline expectations depend on which method MDOT selects. If the department chooses the floating span approach, construction could begin in 2028 and take two to three years to complete. If MDOT proceeds with the in-place repair method, work would likely start toward the end of summer 2027.
Preparing the Community
Before major bridge work begins, MDOT is reconfiguring traffic patterns in downtown Houghton and Hancock to create alternative routes and reduce congestion during the larger project.
Work begins Tuesday, September 8, on Montezuma Avenue (southbound US 41), Bridge Street, and Quincy Street in downtown Houghton. The project will reconfigure traffic on the west end of downtown to give drivers more options to re-enter Sheldon Avenue from Montezuma Avenue and construct a left turn lane on Montezuma Avenue for Bridge Street/Quincy Street access.
“We are actually doing some preliminary work to try to make any traffic impacts from the work that we’re doing on the bridge a little bit less harsh to folks in Houghton and Hancock,” Weingarten said. “We are going to be working with the city of Houghton to make some improvements on southbound US 41, that’s Montezuma Avenue in Houghton, and also on Bridge Street and Quincy Street in downtown Houghton.”
The reconfiguration will allow southbound traffic on US 41 to return to northbound US 41 by taking Montezuma Avenue and Bridge Street past the parking structures and back onto Sheldon Avenue, giving drivers an alternative to traveling all the way to the end of town.
MDOT does not anticipate additional preparation work in 2026 after the September project concludes. In spring or early summer 2027, the department will install a temporary traffic signal at Sheldon Avenue and Bridge Street/Quincy Street.
“That temporary traffic signal at Quincy and Sheldon, we’d be looking at installing sometime next, probably early next summer,” Weingarten said. “We don’t have a specific date on that yet, but we’ll let folks know when that’s gonna happen. That will probably be the next thing that folks will notice. Other than routine maintenance work on the bridge, which we do every year like cable greasing. We’ve got some of that coming up.”
Communication and Contingency Planning
As MDOT continues finalizing project details, several critical questions remain unanswered. Questions that will require extensive coordination between the department, municipalities, first responders, and residents.
The most pressing unknown: how will traffic cross the Portage Canal while the bridge undergoes major reconstruction?
“What form that’s going to take, whether that’s a floating bridge of some sort, potentially a ferry. There’s a lot of ideas right now. We have not settled on a particular plan for that,” Weingarten said. “It’s possible that the outage may be short enough that we don’t need to have extensive facilities for moving folks across. But this is something that’s got to be planned well in advance.”
Emergency medical access presents another challenge. Hospitals serving the Keweenaw Peninsula are located on the north side of the canal, and MDOT must ensure ambulance and emergency services can reach patients during bridge work.
“We know in the past when we’ve had major projects on the bridge, we’ve been able to maintain ambulance service across the bridge. We will work with local officials to figure out something similar for this project too,” Weingarten said.
One potential solution under consideration involves positioning a helicopter on the southern side in Houghton for emergency medical transport, though the feasibility depends on how long the bridge remains out of service.
“The type of contingency plans we’d have to make would be based on how long the bridge is expected to be out of commission. It’s a different contingency if it’s a matter of weeks versus a matter of hours,” Weingarten said. “Depending on what the final plan is, we will make determinations about that. A helicopter for medical emergencies is definitely something that could be under consideration.”
MDOT hopes to provide more concrete answers by next summer. The department emphasizes its commitment to working with municipalities, first responders, and community residents to ensure everyone understands what will happen when the span is replaced.
“By next summer we hope to have a more concrete timeline for exactly what the project would be. We’ll be able to let people know at that point when it’s going to be starting,” Weingarten said.
