US Bridges

F.A.S.12 over Cahaba River

Fair

Bibb County, Alabama · 2.MI NW AL25 CO 27 · Structure no. 004309

Built
1952
73 years old
Condition
Fair
inspected December 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
508 ft
4 main spans
Daily traffic
262
1989 count
Owner
County
County Highway Agency

About this bridge

F.A.S.12 over Cahaba River is a steel stringer/multi-beam or girder carrying F.A.S.12 over Cahaba River in Bibb County, Alabama. It was built in 1952, so it is 73 years old, older than the Alabama average of 51.1 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 262 vehicles a day, roughly 20% of them trucks, projected to reach 400 by 2030. The structure is 508 ft (154.8 m) long and 29 ft wide. If it were closed, the detour would be 19.3 mi (31 km).

Location

Open in Google Maps
CarriesF.A.S.12
CrossesCahaba River
Location2.MI NW AL25 CO 27
RouteCounty Highway 12
CountyBibb County
StateAlabama
Coordinates33.01909, -87.07854
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating36 US tons
Inventory rating21.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4 (+4 approach)
Design loadH 15
Structure length508 ft (154.8 m)
Longest span362 ft (110.3 m)
Deck width29 ft (8.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic262 (1989)
Projected traffic400 by 2030
Trucks20%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.3 mi (31 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$3.6 million (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was F.A.S.12 over Cahaba River built?

It was built in 1952, making it 73 years old in 2025.

What condition is F.A.S.12 over Cahaba River 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 2024.

How much traffic does F.A.S.12 over Cahaba River carry?

About 262 vehicles per day (1989 count), of which roughly 20% are trucks.

How long is F.A.S.12 over Cahaba River?

The structure is 508 ft (154.8 m) long with a longest span of 362 ft (110.3 m) and a deck 29 ft wide.

Who owns F.A.S.12 over Cahaba River?

It is owned by the County Highway Agency.