US Bridges

Nfa A320 over Powder Mill Branch

FairPosted for load

Warren County, Tennessee · 1MI North of SR1 · Structure no. 890A3200001

Built
1960
65 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
30 ft
1 main span
Daily traffic
10
2020 count
Owner
County
County Highway Agency

About this bridge

Nfa A320 over Powder Mill Branch is a steel stringer/multi-beam or girder carrying Nfa A320 over Powder Mill Branch in Warren County, Tennessee. It was built in 1960, so it is 65 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. Its operating status is: posted for load restriction.

It carries about 10 vehicles a day, roughly 2% of them trucks, projected to reach 16 by 2042. The structure is 30 ft (9.1 m) long and 12 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesNfa A320
CrossesPowder Mill Branch
Location1MI North of SR1
RouteCounty Highway 320
CountyWarren County
StateTennessee
Coordinates35.65892, -85.67403
Functional classRural Local

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment6: Equal to present minimum criteria
Operating rating24.7 US tons
Inventory rating15 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadUnknown
Structure length30 ft (9.1 m)
Longest span29 ft (8.8 m)
Deck width12 ft (3.7 m)
Roadway width12 ft (3.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10 (2020)
Projected traffic16 by 2042
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$434,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa A320 over Powder Mill Branch built?

It was built in 1960, making it 65 years old in 2025.

What condition is Nfa A320 over Powder Mill Branch 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 May 2023.

How much traffic does Nfa A320 over Powder Mill Branch carry?

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

How long is Nfa A320 over Powder Mill Branch?

The structure is 30 ft (9.1 m) long with a longest span of 29 ft (8.8 m) and a deck 12 ft wide.

Who owns Nfa A320 over Powder Mill Branch?

It is owned by the County Highway Agency.