MADISON, Wis. -- In the wake of the bridge collapse in Minneapolis, Wisconsin authorities on Thursday reassured commuters and travelers about the safety of bridges across the state and in the Madison area.

There are a little more than 13,600 bridges in Wisconsin, and 13 percent of those are categorized as either structurally deficient or functionally obsolete in the state. The national average for structurally deficient or functionally obsolete bridges is 22 percent.

Structurally deficit means a bridge has some elements needing corrective action but that it isn't necessarily unsafe. Functionally obsolete means that the bridge is outdated for its current use, WISC-TV reported.

When a downtown Milwaukee bridge buckled in December of 2000, Finn Hubbard, a state Department of Transportation bridge engineer, was one of the first experts called. On Thursday, Hubbard reassured the public that Wisconsin's bridges are inspected, upgraded and repaired regularly.

The six-lane Hoan Bridge in Milwaukee underwent major repairs almost seven years ago. A portion of the bridge dropped several feet when girders cracked almost the entire length, WISC-TV reported.

"For bridge failure in Wisconsin, that would be considered the worst one. We did not have any injuries or loss of life, and we were very fortunate in that respect," Hubbard said.

When the Hoan Bridge buckled and shifted, Hubbard was put in charge of finding the cause and figuring out how to repair it.

"(We) nearly lost the bridge. It probably shouldn't have stayed up there, but it did," Hubbard said.

Thousands of travelers rely on area highway bridges, many of which are structurally deficient. Experts said those bridges are safe but need some work.

"The bridges are perfectly safe. They are very good bridges. They're in good shape. The fact they fall into that category just kind of puts a light on them that maybe we want to do something with those over the next 20 years," Hubbard said.

Among those that need work is the Interstate 90/94 bridge in Rock County, WISC-TV reported.

"It's not an emergency because we don't have a big issue with it. But for safety sake, it would be a good bridge to replace over the next 20, 30 years," Hubbard said.

The interstate bridge over the Wisconsin River was built in the 1960s. It is on the federally mandated two-year inspection cycle like all bridges, and Hubbard said it is in good shape.

The heavily traveled Mud Lake Bridge on the Beltline is one of the area's newest. It was constructed in the mid-1980s.

"That is a very stout bridge. It has a lot of girders underneath it (and) a lot of repetition to it. That bridge will not give us any trouble," Hubbard said.

Hubbard said that the bridge collapse in Minnesota is a rare occurrence and that Minnesota officials could learn something from the Hoan Bridge experience, like Wisconsin has.

"People should not be afraid of the bridges. We do a lot of good work with our inspections. They're safe and people should feel confident in their bridge engineers," Hubbard said.

Hubbard said that based on his experience with the Hoan Bridge recovery, Minnesota officials called him Thursday morning. He said he gave Minnesota authorities advice on assembling a team to figure out what caused the collapse.

The American Society of Civil Engineers this year gave Wisconsin bridges a "C" grade. It's an improvement from previous reports, but the society said that Wisconsin doesn't spend nearly enough money on bridge maintenance and repairs.