The orange barrels, barricades and detours that have cropped up this week on Interstate 39 and Highway 16 in Portage are just the beginning of some major transportation changes — including the construction of Columbia County’s first roundabout.
They’re multiple projects, but they’re closely related, said Matt Dapp, project manager for the Wisconsin Department of Transportation.
And all told, they could cost as much as $7 million — mostly federal dollars.
Drivers accustomed to exiting northbound I-39 to westbound Highway 16 (Exit 89B, toward Wisconsin Dells) might want to allow a few more minutes of travel time than usual, to navigate a detour.
The exit will be closed at least through Tuesday, and when it reopens, it no longer will be a cloverleaf, but a T-intersection with a stop sign.
For now, drivers are being directed to continue to Exit 92 at Highway 51, where they would turn around and head back south to exit either direction on Highway 16.
According to Dapp, the intersection restructuring is designed to decrease the number of crashes in the area that stem from drivers weaving across lanes as they move from the ramp to westbound Highway 16.
When the work is done early next week, he said, there still will be two separate exits from northbound I-39 — 89A for those heading east on 16 toward downtown Portage and 89B for westbound motorists. Eventually, he said, there will be just one northbound exit toward Highway 16.
Other projects going on at the same time, Dapp said, entail building three I-39 crossovers in the median, to prepare for rerouting that will be necessary when the time comes to paint and refurbish four I-39 bridges — the north and southbound bridges over the Wisconsin River and the north and southbound bridges over Canadian Pacific Railroad tracks.
During this work, expected to begin in the spring, the interstate will be closed in one direction, with northbound and southbound traffic rerouted temporarily to one lane in each direction.
Work also is expected to start in the spring on a roundabout that will replace the intersection of Highway 16, Highway 127 and the I-39 southbound on-ramp.
Some attendees at a January 2016 DOT open house at the Portage Municipal Building expressed concern about whether drivers in the area know how to navigate a roundabout.
A roundabout is an intersection with a large circular island in the middle. Instead of the traffic from different directions taking turns via stop signs or traffic signals, all traffic enters the roundabout by yielding to drivers from the left who are already in it and drives around the circle, following signs and arrows guiding them to their desired direction.
Bill Tierney, who was mayor of Portage when the open house was held, said he favored a roundabout because, as a paramedic, he had worked often at crash scenes at conventional intersections, where the crashes tend to be more severe than they are in roundabouts.
Dapp said it was his impression, at subsequent public meetings, that Portage-area residents had become more receptive to the concept of a roundabout at highways 16 and 127.
The roundabout project also will include pavement improvements in deteriorated areas of Highway 16 between Boeck Road and the railroad overpass south of Silver Lake Drive.
The project that’s going on right now, Dapp said, and costs a little more than $4 million, of which 80 percent comes from federal transportation dollars and the rest from the state. Zenith Tech Inc. of Waukesha is the contractor.
The bids have not yet been let for the upcoming projects, including the roundabout, which have an estimated cost of between $2 million and $3 million.
Dapp said there will be traffic disruptions, lane closures and detours in northwestern Portage for much of next year, but once the work is done, he said he believes motorists will appreciate a safer roadway.
“It will be an improvement,” he said. “There are quite a lot of crashes in the area.”