US Bridges

Nfa 843 (sa 7408) over Calbes Creek

Good

Robertson County, Tennessee · 4.1 MI NW JCT SR49&SR257 · Structure no. 74S62770005

Built
1977
48 years old
Condition
Good
inspected May 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
39 ft
1 main span
Daily traffic
461
2021 count
Owner
County
County Highway Agency

About this bridge

Nfa 843 (sa 7408) over Calbes Creek is a prestressed concrete stringer/multi-beam or girder carrying Nfa 843 (sa 7408) over Calbes Creek in Robertson County, Tennessee. It was built in 1977, so it is 48 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 461 vehicles a day, roughly 3% of them trucks, projected to reach 656 by 2040. The structure is 39 ft (11.9 m) long and 32 ft wide. If it were closed, the detour would be 5 mi (8 km).

CarriesNfa 843 (sa 7408)
CrossesCalbes Creek
Location4.1 MI NW JCT SR49&SR257
RouteCounty Highway 843
Coordinates36.49667, -87.00784
Functional classRural Minor Collector

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
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 adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59.5 US tons
Inventory rating35.7 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length39 ft (11.9 m)
Longest span38 ft (11.6 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic461 (2021)
Projected traffic656 by 2040
Trucks3%
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 statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Nfa 843 (sa 7408) over Calbes Creek built?

It was built in 1977, making it 48 years old in 2025.

What condition is Nfa 843 (sa 7408) over Calbes Creek 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 May 2024.

How much traffic does Nfa 843 (sa 7408) over Calbes Creek carry?

About 461 vehicles per day (2021 count), of which roughly 3% are trucks.

How long is Nfa 843 (sa 7408) over Calbes Creek?

The structure is 39 ft (11.9 m) long with a longest span of 38 ft (11.6 m) and a deck 32 ft wide.

Who owns Nfa 843 (sa 7408) over Calbes Creek?

It is owned by the County Highway Agency.