State officials have stepped up patrols near Winona's Interstate Bridge after a sensor detected thousands of drivers breaking weight limits designed to protect the 69-old structure.
The state Department of Transportation imposed a 40-ton weight limit in June after the discovery of nine corroded gusset plates and nearly a month of inspections and repairs. In the last six months of 2010, more than 12,000 vehicles crossed with an illegally sized load - the heaviest weighing in at about 180,000 pounds, more than double the limit.
"It's a traffic violation, but the bigger concern for us is the increased wear on the bridge," MnDOT spokeswoman Kristine Hernandez said.
The department sent letters to city officials and local groups regarding the violations.
A sensor on the Wisconsin side weighs cars and trucks as they pass over, and those lugging an illegal load are taken to a weigh station about 45 minutes away, Hernandez said. In December, the department started paying overtime to State Patrol officers for stepped-up enforcement.
Drivers are ticketed and fined based on the severity of the violation, and each must undergo a trial.
Added stress from heavy trucks could lead to more work on the bridge this summer, creating a nuisance for drivers with lane closures and construction. Weightier loads also create a risk for other drivers.
"It costs taxpayers in the long run, regardless," Hernandez said. "We're having to go in there and do repairs."
Weight restrictions will be in place until the bridge is either rehabilitated or replaced. Work is scheduled to begin in 2014.