US Bridges

Nfa 1179 (sa 1408) over Knob Creek

Fair

Clay County, Tennessee · 3 MI S of SR-52 · Structure no. 14S42320001

Built
1976
49 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
185 ft
5 main spans
Daily traffic
461
2021 count
Owner
County
County Highway Agency

About this bridge

Nfa 1179 (sa 1408) over Knob Creek is a prestressed concrete continuous stringer/multi-beam or girder carrying Nfa 1179 (sa 1408) over Knob Creek in Clay County, Tennessee. It was built in 1976, so it is 49 years old, older than the Tennessee average of 47.4 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 461 vehicles a day, roughly 2% of them trucks, projected to reach 738 by 2042. The structure is 185 ft (56.5 m) long and 32 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

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CarriesNfa 1179 (sa 1408)
CrossesKnob Creek
Location3 MI S of SR-52
RouteCounty Highway 1179
CountyClay County
StateTennessee
Coordinates36.52405, -85.54137
Functional classRural Minor 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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 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 geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71.1 US tons
Inventory rating49.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length185 ft (56.5 m)
Longest span39 ft (11.9 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic461 (2021)
Projected traffic738 by 2042
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa 1179 (sa 1408) over Knob Creek built?

It was built in 1976, making it 49 years old in 2025.

What condition is Nfa 1179 (sa 1408) over Knob Creek 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 April 2024.

How much traffic does Nfa 1179 (sa 1408) over Knob Creek carry?

About 461 vehicles per day (2021 count), of which roughly 2% are trucks.

How long is Nfa 1179 (sa 1408) over Knob Creek?

The structure is 185 ft (56.5 m) long with a longest span of 39 ft (11.9 m) and a deck 32 ft wide.

Who owns Nfa 1179 (sa 1408) over Knob Creek?

It is owned by the County Highway Agency.