A heavily traveled bridge carrying Mt. Nebo Road over I-79 in Sewickley Hills was squeezed down to a single lane Thursday after inspectors found a large crack on the underside of the deck. Crews worked overnight to chip away loose concrete, and PennDOT ordered the restriction as a safety move while engineers map out a closer inspection beneath the span.
According to CBS Pittsburgh, PennDOT engineers spotted the crack during routine checks and cleared debris from the deck before shutting down one side. New signs now funnel drivers onto I-79 southbound to the Route 65 exit and then back north, and some eastbound motorists were forced either onto the interstate or into U-turns just to reach their usual routes.
Why inspectors pulled a lane
PennDOT's Bridge Safety Inspection Manual (Publication 238) calls for emergency restrictions or closures when inspectors find serious problems that could threaten public safety, including significant deck deterioration. A recent review by TRIP found that about 14 percent of Pennsylvania's local bridges are rated poor or structurally deficient, a backdrop that helps explain why the agency is quick to tighten traffic when something looks off.
Detours and commute impact
Signs at the scene instruct drivers to detour via I-79 southbound to Route 65 and then loop back north, a setup meant to keep local traffic off the damaged section while crews work underneath. "I don't do highways, so I need to use that road unless there's another back road," one motorist told CBS Pittsburgh, a snapshot of the frustration for drivers who rely on Mt. Nebo Road as a non-interstate lifeline.
Local context
Pittsburgh still lives with the memory of the 2022 Fern Hollow collapse, when a city-owned bridge failed, and federal investigators later pointed to gaps in inspection and maintenance. That disaster has put a spotlight on any hint of structural trouble. The citywide wake-up call is a big reason visible cracking now draws an urgent response and thorough follow-up inspections, according to reporting by The Associated Press.
What to expect next
PennDOT engineers plan to examine the underside of the Mt. Nebo Road span to see whether the crack reaches other components and whether more lane closures or new weight limits are needed. For real-time travel conditions and official advisories, PennDOT directs drivers to 511PA and District 11 updates for camera views and lane-closure notices.
