US Bridges

Colerain ST over Saw Mill Run Stream

Fair

Allegheny County, Pennsylvania · SW06 Saw Mill Run No. 6 · Structure no. 000000000002390

Built
1920
105 years old, rebuilt 2011
Condition
Fair
inspected July 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
33 ft
1 main span
Daily traffic
6,348
2023 count
Owner
County
County Highway Agency

About this bridge

Colerain ST over Saw Mill Run Stream is a prestressed concrete box beam or girders - multiple carrying Colerain ST over Saw Mill Run Stream in Allegheny County, Pennsylvania. It was built in 1920 and reconstructed in 2011, so it is 105 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 6,348 vehicles a day, roughly 10% of them trucks, projected to reach 6,500 by 2043. The structure is 33 ft (10.1 m) long and 30 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesColerain ST
CrossesSaw Mill Run Stream
LocationSW06 Saw Mill Run No. 6
RouteCounty Highway 0
CountyAllegheny County
StatePennsylvania
Coordinates40.39627, -79.99791
Functional classUrban Local

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating109 US tons
Inventory rating65 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length33 ft (10.1 m)
Longest span31 ft (9.4 m)
Deck width30 ft (9 m)
Roadway width26 ft (8 m)
Vertical clearance over deck17 ft (5 m)

Traffic and service

Average daily traffic6,348 (2023)
Projected traffic6,500 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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$81,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Colerain ST over Saw Mill Run Stream built?

It was built in 1920, making it 105 years old in 2025. It was reconstructed in 2011.

What condition is Colerain ST over Saw Mill Run Stream 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 Colerain ST over Saw Mill Run Stream carry?

About 6,348 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Colerain ST over Saw Mill Run Stream?

The structure is 33 ft (10.1 m) long with a longest span of 31 ft (9.4 m) and a deck 30 ft wide.

Who owns Colerain ST over Saw Mill Run Stream?

It is owned by the County Highway Agency.