US Bridges

Nfa 1796 (sa 4304) over Duck River

Fair

Humphreys County, Tennessee · 3 M. W. SR13. · Structure no. 43017960001

Built
1976
49 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
560 ft
7 main spans
Daily traffic
156
2021 count
Owner
County
County Highway Agency

About this bridge

Nfa 1796 (sa 4304) over Duck River is a prestressed concrete continuous stringer/multi-beam or girder carrying Nfa 1796 (sa 4304) over Duck River in Humphreys 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 156 vehicles a day, roughly 3% of them trucks, projected to reach 250 by 2042. The structure is 560 ft (170.7 m) long and 28 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

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CarriesNfa 1796 (sa 4304)
CrossesDuck River
Location3 M. W. SR13.
RouteCounty Highway 1796
CountyHumphreys County
StateTennessee
Coordinates35.94747, -87.82025
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.
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57.5 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, precast panels
Main spans7
Design loadHS 20
Structure length560 ft (170.7 m)
Longest span79 ft (24.1 m)
Deck width28 ft (8.5 m)
Roadway width25 ft (7.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic156 (2021)
Projected traffic250 by 2042
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Nfa 1796 (sa 4304) over Duck River built?

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

What condition is Nfa 1796 (sa 4304) over Duck 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 October 2023.

How much traffic does Nfa 1796 (sa 4304) over Duck River carry?

About 156 vehicles per day (2021 count), of which roughly 3% are trucks.

How long is Nfa 1796 (sa 4304) over Duck River?

The structure is 560 ft (170.7 m) long with a longest span of 79 ft (24.1 m) and a deck 28 ft wide.

Who owns Nfa 1796 (sa 4304) over Duck River?

It is owned by the County Highway Agency.