US Bridges

West Liberty Ave over Saw Mill Run

Fair

Allegheny County, Pennsylvania · @ S End of Liberty Tunnel · Structure no. 000000000001805

Built
1926
99 years old
Condition
Fair
inspected December 2023
Type
Arch - Deck
Concrete
Length
43 ft
1 main span
Daily traffic
42,292
2023 count
Owner
State
State Highway Agency

About this bridge

West Liberty Ave over Saw Mill Run is a concrete arch - deck carrying West Liberty Ave over Saw Mill Run in Allegheny County, Pennsylvania. It was built in 1926, so it is 99 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 5 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 42,292 vehicles a day, roughly 6% of them trucks, projected to reach 43,648 by 2032. The structure is 43 ft (13.1 m) long and 93 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesWest Liberty Ave
CrossesSaw Mill Run
Location@ S End of Liberty Tunnel
RouteState Highway 0
CountyAllegheny County
StatePennsylvania
Coordinates40.41441, -80.00934
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54 US tons
Inventory rating36 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadHS 20
Structure length43 ft (13.1 m)
Longest span43 ft (13.1 m)
Deck width93 ft (28.2 m)
Roadway width83 ft (25.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic42,292 (2023)
Projected traffic43,648 by 2032
Trucks6%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$157,000
NavigationNo navigation control on waterway

Frequently asked questions

When was West Liberty Ave over Saw Mill Run built?

It was built in 1926, making it 99 years old in 2025.

What condition is West Liberty Ave over Saw Mill 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 December 2023.

How much traffic does West Liberty Ave over Saw Mill Run carry?

About 42,292 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is West Liberty Ave over Saw Mill Run?

The structure is 43 ft (13.1 m) long with a longest span of 43 ft (13.1 m) and a deck 93 ft wide.

Who owns West Liberty Ave over Saw Mill Run?

It is owned by the State Highway Agency.