US Bridges

Nfa D405 over Little Flat Creek

Fair

Knox County, Tennessee · W of US11W at Grainger CO · Structure no. 470D4050001

Built
1963
62 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
60 ft
1 main span
Daily traffic
230
2020 count
Owner
County
County Highway Agency

About this bridge

Nfa D405 over Little Flat Creek is a prestressed concrete stringer/multi-beam or girder carrying Nfa D405 over Little Flat Creek in Knox County, Tennessee. It was built in 1963, so it is 62 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 230 vehicles a day, roughly 2% of them trucks, projected to reach 368 by 2040. The structure is 60 ft (18.4 m) long and 21 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesNfa D405
CrossesLittle Flat Creek
LocationW of US11W at Grainger CO
RouteCounty Highway 405
CountyKnox County
StateTennessee
Coordinates36.1303, -83.74948
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 inspectionMay 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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating39.7 US tons
Inventory rating26.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckCorrugated steel
Main spans1
Design loadUnknown
Structure length60 ft (18.4 m)
Longest span57 ft (17.4 m)
Deck width21 ft (6.3 m)
Roadway width18 ft (5.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic230 (2020)
Projected traffic368 by 2040
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$238,000 (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa D405 over Little Flat Creek built?

It was built in 1963, making it 62 years old in 2025.

What condition is Nfa D405 over Little Flat 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 May 2024.

How much traffic does Nfa D405 over Little Flat Creek carry?

About 230 vehicles per day (2020 count), of which roughly 2% are trucks.

How long is Nfa D405 over Little Flat Creek?

The structure is 60 ft (18.4 m) long with a longest span of 57 ft (17.4 m) and a deck 21 ft wide.

Who owns Nfa D405 over Little Flat Creek?

It is owned by the County Highway Agency.