Nearly 7% of Wisconsin bridges ‘structurally deficient’


Photo: Morgan Feltz / The Advance-Titan — The Oregon/Jackson Street bridge is under construction until the end of September. Until then, no foot traffic or vehicles are able to pass over it.

Katie Pulvermacher, Managing Editor and News Editor

Of Wisconsin’s 14,307 bridges scaling state and local roadways, 987 or 6.9% are classified as “structurally deficient,” according to the American Road & Transportation Builders Association (ARTBA).

A bridge being “structurally deficient” means one of the key elements in a bridge’s structure is in poor or worse condition.

The state of bridge conditions is apparent in Oshkosh, since the Oregon/Jackson Street bridge has been stuck in an upright position since May. The bridge is currently closed to all car and foot traffic after a bridge inspection uncovered damaged gear teeth in the gearbox on the south leaf span.

The bridge will remain upright and closed to traffic until an estimated date of Sept. 30, 2022.

The process needed to restore the bridge is complex, with the parts manufacturing taking an approximate 12 weeks. The total estimated cost is $136,000, according to the Wisconsin Department of Transportation (WisDOT). 

According to WisDOT, “All of Wisconsin’s bridges are inspected at least once every two years and sometimes more frequently depending on a bridge’s age, traffic load and any known deficiencies or load restrictions.” Northeast Regional Communications Manager Mark Kantola said this is true for Oshkosh. 

WisDOT Bridge Engineering Specialist Jim McDowell said Oshkosh bridges are checked more often than required. 

“Winnebago County Highway Department staff performs monthly checks and greases all of the Oshkosh bascules to help the DOT make sure the bridges stay in good working order,” McDowell said. “They are my eyes and ears to help me address any potential problems, so we keep breakdown events to a minimum.”

He said larger projects such as painting the entire structure are done by a contractor through a bid process.

WisDOT defines a bridge as “any structure spanning 20 feet or more that carries motor vehicle traffic.”

A WisDOT MAPSS Performance Improvement Report shares that from January – December of 2021, the percentage of state-owned or maintained bridges rated fair or above is 97.5%. 

However, there is a fine line of discrepancies since theWisDOT report does not include locally owned bridges. What matters is some bridges are in need of repairs. These repairs would cost an estimated $1.7 million, according to ARTBA.  

“But the really important thing to note is that poor doesn’t mean unsafe,” said Josh Dietsche, state bridge engineer with WisDOT, in an interview with ABC First Alert. “Poor means that there is some level, some advanced level of deterioration, but we inspect bridges on a regular basis. And as they deteriorate more, we inspect them more frequently to make sure that they are still safe for the public to use.”

The most structurally deficient bridges in Wisconsin are located in the counties of Milwaukee, Dane, Dunn, Columbia and Waukesha, according to ARTBA.

Inspection processes can take from an hour to over a week. WisDOT’s trained bridge inspectors follow Federal Highway Administration (FHWA) standards and guidelines.

Inspectors survey the “superstructure or beams that support the deck looking for cracks, rust or any problems with bolts or rivets, the substructure units (which support the superstructure), bridge approaches and the deck or surface of the bridge” and divers check supporting piers on bridges over large bodies of water.

McDowell said the larger, annual inspections in Oshkosh are very thorough. 

“During our annual inspection normally done each spring we identify and then program work that needs to be done,” McDowell said. “If that work is larger in scope it takes longer to program. Most of the yearly improvement work is done by DOT and Winnebago County staff.”

Even though the state of Wisconsin as a whole has bridges in poor condition, Oshkosh bridges are in decent condition, McDowell said.

“The Oshkosh lift bridges are in good condition and due to their complexity, there is more maintenance performed on a monthly basis during the navigation season to make sure they stay in good operating condition,” McDowell said.