US Bridges

Nfa 999 (sa 6026) over Knob Creek

Fair

Maury County, Tennessee · 6 M. Nw. Columbia. · Structure no. 60009990001

Built
1950
75 years old
Condition
Fair
inspected April 2024
Type
Tee Beam
Concrete
Length
72 ft
2 main spans
Daily traffic
788
2021 count
Owner
County
County Highway Agency

About this bridge

Nfa 999 (sa 6026) over Knob Creek is a concrete tee beam carrying Nfa 999 (sa 6026) over Knob Creek in Maury County, Tennessee. It was built in 1950, so it is 75 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 788 vehicles a day, roughly 3% of them trucks, projected to reach 1,376 by 2040. The structure is 72 ft (21.9 m) long and 23 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesNfa 999 (sa 6026)
CrossesKnob Creek
Location6 M. Nw. Columbia.
RouteCounty Highway 999
CountyMaury County
StateTennessee
Coordinates35.69282, -87.08117
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
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 protection6 SatisfactoryStructural elements show some minor deterioration.
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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadH 15
Structure length72 ft (21.9 m)
Longest span35 ft (10.7 m)
Deck width23 ft (7 m)
Roadway width20 ft (6.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic788 (2021)
Projected traffic1,376 by 2040
Trucks3%
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 with deck rehabilitation or replacement
Estimated improvement cost$278,000 (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa 999 (sa 6026) over Knob Creek built?

It was built in 1950, making it 75 years old in 2025.

What condition is Nfa 999 (sa 6026) 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 999 (sa 6026) over Knob Creek carry?

About 788 vehicles per day (2021 count), of which roughly 3% are trucks.

How long is Nfa 999 (sa 6026) over Knob Creek?

The structure is 72 ft (21.9 m) long with a longest span of 35 ft (10.7 m) and a deck 23 ft wide.

Who owns Nfa 999 (sa 6026) over Knob Creek?

It is owned by the County Highway Agency.