About a dozen bridges in Peoria and Tazewell counties structurally deficient or functionally obsolete
Slightly more than a dozen smaller bridges in the area’s two most heavily traveled counties are considered "structurally deficient" or "functionally obsolete," officials said Thursday.
That, however, puts those counties well below the statewide percentage for bridges needing repair or replacement, and the state itself is ahead of the curve compared to nationwide numbers.
And while the 40-year-old interstate bridge in Minnesota’s Twin Cities that collapsed Wednesday was considered "structurally deficient," that term sounds far more ominous than its technical definition intends, one official said.
"I cringed when I heard" that term used in news reports of the tragedy, said Peoria County Highway Department Superintendent Tom McFarland. "There’s so many meanings" attached to it. "It doesn’t necessarily mean that bridge was ready for collapse."
Three "highly trained" inspectors in McFarland’s department have the duty to inspect 180 bridges throughout the county at least every two to four years — 80 on the county’s roads and 100 under the responsibilities of townships that "pay their share" for the bridges’ maintenance, he said.
Of those, about 10 are considered functionally obsolete, he said. They’re still in use, but are restricted by vehicle weight limits. "We try to replace two to three bridges a year," McFarland said.
The 10 leaves the county with about 6 percent of its bridges not under federal or state supervision in the "deficient" or "obsolete" categories.
In Tazewell County, only about four of the 186 bridges inspected by its Highway Department are structurally deficient or functionally obsolete, said county Highway Superintendent John Anderson. That amounts to 2 percent.
Of the state’s nearly 26,000 total bridges, about 16 percent are deficient or obsolete, according to the American Society of Civil Engineers, which lists the nationwide level of such bridges at 26 percent. The Federal Highway Administration ranks Illinois 13th among states in those categories.
According to the engineers society, a structurally deficient bridge may either be closed or restricted to light vehicles because of deteriorating components. A functionally obsolete bridge has older design features and, while not unsafe for all vehicles, can’t safely accommodate heavier traffic volumes and vehicle weights.
The results of regular inspections, required under FHA mandates, determine where bridges stand on a 100-point rating scale. A bridge can be determined deficient above a score of 50, but at that level is considered "eligible for replacement," McFarland said. "It’s a very complex rating process."
"If there’s something good to come" from the Minnesota bridge tragedy, he added, "the civil engineering industry will learn from it" as local governments continue to confront the issues of their aging bridges.
Michael Smothers can be reached at (309) 686-3287 or email@example.com.