US Bridges

Nfa A793 over Sulphur Branch

Good

Overton County, Tennessee · 3 MI West of SR 42 · Structure no. 670A3900001

Built
2007
18 years old
Condition
Good
inspected December 2024
Type
Culvert
Concrete Continuous
Length
30 ft
2 main spans
Daily traffic
280
2020 count
Owner
County
County Highway Agency

About this bridge

Nfa A793 over Sulphur Branch is a concrete continuous culvert carrying Nfa A793 over Sulphur Branch in Overton County, Tennessee. It was built in 2007, so it is 18 years old, younger 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 280 vehicles a day, roughly 2% of them trucks, projected to reach 448 by 2040. The structure is 30 ft (9 m) long and 48 ft wide. If it were closed, the detour would be 5 mi (8 km).

CarriesNfa A793
CrossesSulphur Branch
Location3 MI West of SR 42
RouteCounty Highway 793
Coordinates36.30605, -85.37735
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 inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating78.3 US tons
Inventory rating35.7 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length30 ft (9 m)
Longest span14 ft (4.2 m)
Deck width48 ft (14.7 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic280 (2020)
Projected traffic448 by 2040
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa A793 over Sulphur Branch built?

It was built in 2007, making it 18 years old in 2025.

What condition is Nfa A793 over Sulphur 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 December 2024.

How much traffic does Nfa A793 over Sulphur Branch carry?

About 280 vehicles per day (2020 count), of which roughly 2% are trucks.

How long is Nfa A793 over Sulphur Branch?

The structure is 30 ft (9 m) long with a longest span of 14 ft (4.2 m) and a deck 48 ft wide.

Who owns Nfa A793 over Sulphur Branch?

It is owned by the County Highway Agency.