South Twelfth ST over Norfolk Southern RR
FairAllegheny County, Pennsylvania · 104 S 12th ST Bridge · Structure no. 000000000002454
- Built
- 1901
- 124 years old, rebuilt 1994
- Condition
- Fair
- inspected October 2024
- Type
- Stringer/Multi-beam or Girder
- Steel
- Length
- 75 ft
- 1 main span
- Daily traffic
- 3,000
- 2020 count
- Owner
- City
- City or Municipal Highway Agency
About this bridge
South Twelfth ST over Norfolk Southern RR is a steel stringer/multi-beam or girder carrying South Twelfth ST over Norfolk Southern RR in Allegheny County, Pennsylvania. It was built in 1901 and reconstructed in 1994, so it is 124 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 3,000 vehicles a day, roughly 4% of them trucks, projected to reach 3,500 by 2040. The structure is 75 ft (22.9 m) long and 40 ft wide. If it were closed, the detour would be 1.9 mi (3 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was South Twelfth ST over Norfolk Southern RR built?
It was built in 1901, making it 124 years old in 2025. It was reconstructed in 1994.
What condition is South Twelfth ST over Norfolk Southern RR 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 October 2024.
How much traffic does South Twelfth ST over Norfolk Southern RR carry?
About 3,000 vehicles per day (2020 count), of which roughly 4% are trucks.
How long is South Twelfth ST over Norfolk Southern RR?
The structure is 75 ft (22.9 m) long with a longest span of 71 ft (21.6 m) and a deck 40 ft wide.
Who owns South Twelfth ST over Norfolk Southern RR?
It is owned by the City or Municipal Highway Agency.