US Bridges

Nfa A179 over Key Branch

Good

Hickman County, Tennessee · 2 M N of Nunnelly · Structure no. 410A1790001

Built
1975
50 years old
Condition
Good
inspected September 2023
Type
Culvert
Concrete Continuous
Length
30 ft
2 main spans
Daily traffic
10
2020 count
Owner
County
County Highway Agency

About this bridge

Nfa A179 over Key Branch is a concrete continuous culvert carrying Nfa A179 over Key Branch in Hickman County, Tennessee. It was built in 1975, so it is 50 years old, older than the Tennessee average of 47.4 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 10 vehicles a day, roughly 2% of them trucks, projected to reach 16 by 2041. The structure is 30 ft (9.1 m) long and 16 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesNfa A179
CrossesKey Branch
Location2 M N of Nunnelly
RouteCounty Highway 179
CountyHickman County
StateTennessee
Coordinates35.89052, -87.46606
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71.4 US tons
Inventory rating42.5 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length30 ft (9.1 m)
Longest span10 ft (3 m)
Deck width16 ft (4.9 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10 (2020)
Projected traffic16 by 2041
Trucks2%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$196,000 (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa A179 over Key Branch built?

It was built in 1975, making it 50 years old in 2025.

What condition is Nfa A179 over Key Branch in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in September 2023.

How much traffic does Nfa A179 over Key Branch carry?

About 10 vehicles per day (2020 count), of which roughly 2% are trucks.

How long is Nfa A179 over Key Branch?

The structure is 30 ft (9.1 m) long with a longest span of 10 ft (3 m) and a deck 16 ft wide.

Who owns Nfa A179 over Key Branch?

It is owned by the County Highway Agency.