US Bridges

I-376 over Union RR Thompson Run

Fair

Allegheny County, Pennsylvania · 2.5 MI W of Pa Turnpike · Structure no. 000000000001204

Built
1962
63 years old, rebuilt 2009
Condition
Fair
inspected July 2023
Type
Girder and Floorbeam System
Steel Continuous
Length
706 ft
4 main spans
Daily traffic
52,457
2023 count
Owner
State
State Highway Agency

About this bridge

I-376 over Union RR Thompson Run is a steel continuous girder and floorbeam system carrying I-376 over Union RR Thompson Run in Allegheny County, Pennsylvania. It was built in 1962 and reconstructed in 2009, so it is 63 years old, older than the Pennsylvania average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 52,457 vehicles a day, roughly 7% of them trucks, projected to reach 64,685 by 2032. The structure is 706 ft (215.2 m) long and 102 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesI-376
CrossesUnion RR Thompson Run
Location2.5 MI W of Pa Turnpike
RouteInterstate 376
CountyAllegheny County
StatePennsylvania
Coordinates40.44196, -79.79738
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53 US tons
Inventory rating32 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4 (+1 approach)
Design loadHS 20
Structure length706 ft (215.2 m)
Longest span172 ft (52.4 m)
Deck width102 ft (31.2 m)
Roadway width95 ft (29 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic52,457 (2023)
Projected traffic64,685 by 2032
Trucks7%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway, waterway and railroad
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedDeck rehabilitation with only incidental widening
Estimated improvement cost$3.2 million
NavigationNo navigation control on waterway

Frequently asked questions

When was I-376 over Union RR Thompson Run built?

It was built in 1962, making it 63 years old in 2025. It was reconstructed in 2009.

What condition is I-376 over Union RR Thompson Run in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2023.

How much traffic does I-376 over Union RR Thompson Run carry?

About 52,457 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is I-376 over Union RR Thompson Run?

The structure is 706 ft (215.2 m) long with a longest span of 172 ft (52.4 m) and a deck 102 ft wide.

Who owns I-376 over Union RR Thompson Run?

It is owned by the State Highway Agency.