A collapse is the most dramatic outcome in a bridge’s lifespan.
But it’s just the potential worst-case scenario for the 143 state-inspected bridges in Westmoreland County that are rated in poor condition and are likely to need attention sooner or later, if they haven’t already been closed.
PennDOT lists a bridge as being in poor condition if any one of its components — deck, superstructure, substructure or culvert — has a condition with a low rating. A bridge will be deemed in poor condition when “deterioration of primary structural elements has advanced.”
Even though a bridge that remains open is listed in poor condition, it doesn’t mean it’s ready to collapse, according to Kent Harries, a professor of structural engineering at the University of Pittsburgh.
“Our goal is to make sure that no such thing happens,” he said, “but there’s no such thing as zero probability chance of failure.”
Harries said, “bridges collapse more often than most people recognize.” Unless it’s a particularly large bridge, “generally, you don’t hear about them beyond the region they impact.”
Among area bridge failures of note, Harries cited the 2005 collapse of a concrete bridge beam that supported the deck of the Lakeview Drive bridge over Interstate 70 in South Strabane, Washington County. It fell onto the eastbound lanes of the interstate, resulting in two minor injuries and snarling traffic.
“That bridge just deteriorated to the point where it could no longer support its own weight,” Harries said. “The nature of deterioration is: Corrosion begets more corrosion. That’s indicative of much of our region’s bridge inventory, which tends to be on the older side.”
Harries believes the state’s bridge evaluation system is “generally very good.” But he said resources are insufficient to adequately address the problem of deteriorating spans that the system documents.
PennDOT “has made considerable progress in improving bridge conditions over the last several years” in Westmoreland, Fayette, Washington and Greene counties, according to Melissa R. Maczko, acting safety press officer for PennDOT District 12, which is responsible for those counties.
In 2009, nearly one out of three bridges were in poor condition, but that has been reduced to roughly one out of every eight, or 12%, Maczko said.
“Each bridge is evaluated based on condition, as well as risk assessment factors such as traffic volumes, structure type, as well as other assessment factors,” she said. “A determination is made as to whether the bridge life can be extended through preservation or rehabilitation, or if replacement is the only option.
“There is inadequate funding to replace every poor bridge. Therefore, decisions are made with safety as the first priority.”
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In 2021, PennDOT District 12 completed 25 bridge replacements or rehabilitations, including five in Westmoreland County.
This year, 14 bridge projects are under construction. Half of those are in Westmoreland, including bridges carrying Route 3103 over Jacks Run and Route 4019 over Norfolk Southern Railroad tracks.
In addition, 38 other bridge projects are tentatively scheduled to go to bid this year, including 13 in Westmoreland. Preservation work is planned on 38 more spans.
In the longer term, District 12 officials have tentative plans to bid 78 additional bridge projects through September 2026. Among the proposed Westmoreland projects are rehabilitation of the West Newton Bridge and replacement of the Salina Bridge.
According to PennDOT, 78 of 733 state bridges that are more than 20 feet long in Westmoreland County are in poor condition.
Of the 175 local bridges PennDOT inspects in Westmoreland, 65 are in poor condition.