IRONWOOD -- The project on U.S. 2 near the Montreal River bridge isn't the run-of-the-mill summer roadwork.
Far from it.
The new surface hides the gem of this project, one that Wisconsin transportation officials say is the first of its kind in the nation.
Scales are being installed underneath the highway in both directions on the Michigan side of the Montreal River in the Wisconsin-funded project. The scales weigh vehicles, with an eye towards tractor-trailer rigs, as they pass through -- no stopping necessary.
Cameras will record the trucks that go by. The weight of the truck and the set-up of the axles -- key to determining how the weight of the load is distributed -- are most important. Detecting a truck's speed determines how far apart the axles are.
"You can do all that at 55 mph," said David Simon, roadside facility engineer with the Wisconsin Department of Transportation.
Strain gauges on the westbound bridge will determine what a truck does to the structure, specifically the girders, the most important and load-bearing part of the bridge. Those girders take the most stress as the bridge is traversed.
There are roadways that have these so-called weigh-in-motion scales. There are bridges with strain gauges that show the fatigue bridges sustain when trucks cross.
But this is the first time they will be combined to give such high accuracy, Simon said.
Northwestern University in Evanston, Ill., is conducting the research project. Engineers can receive data as they need to determine what effect trucks that weigh a specific amount have on the bridge.
"That's really important from our standpoint," said Scot Becker, Wisconsin state bridge engineer and development bureau chief for the Bureau of Statistics.
Basically, researchers want to know what trucks do to bridges, specifically to the critical parts of bridges.
"It could lead to better bridge design and more understanding of how bridges work," Simon said. They can "improve the design of bridges if they know what the effects of heavy vehicles are."
Twenty-six gauges throughout the bridge's girders will help measure the displacement of the bridge by a passing truck, Becker said. Displacement is defined as how far the bridge moves as a truck passes over.
These are miniscule movements, invisible to the naked eye. In general, bridges are supposed to move; it's not a problem until the loads are too heavy, in which case the bridge could bend too far. This could damage the girders.
At least on one nearly 50-year-old bridge, the days of engineers having to guess the effect trucks had on it are over, according to Becker.
Prior to the installation of the new equipment, researchers had to guess what weights and axles were going over bridges while testing how the bridges were being strained, he said.
Not anymore.
"We're looking forward to seeing some results from it," Becker said. "It's ... unique."
The Michigan Department of Transportation and universities in Michigan are also interested in the information.
WisDOT officials can also use the information to determine what type of industry is here, Simon said.
They chose to put the scales on the Michigan side of the river because they wanted to catch U.S. 51 traffic also, he said. It is funded by highway improvement fund in Wisconsin with cooperation from MDOT, he said.
The project is expected to be up and running by mid-September, Simon said. Angelo Luppino Inc. of Iron Belt, Wis., is doing the surface work, while International Road Dynamics, based in Saskatchewan, is doing the scales and bridge work.
