US Bridges

Nfa 979 (sa 7401) over I24

Good

Robertson County, Tennessee · 1.3 MI NW JCT I24&SR256 · Structure no. 74I00240003

Built
1973
52 years old
Condition
Good
inspected March 2024
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
297 ft
3 main spans
Daily traffic
326
2021 count
Owner
State
State Highway Agency

About this bridge

Nfa 979 (sa 7401) over I24 is a concrete continuous box beam or girders - multiple carrying Nfa 979 (sa 7401) over I24 in Robertson County, Tennessee. It was built in 1973, so it is 52 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 326 vehicles a day, roughly 3% of them trucks, projected to reach 522 by 2042. The structure is 297 ft (90.5 m) long and 32 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

CarriesNfa 979 (sa 7401)
CrossesI24
Location1.3 MI NW JCT I24&SR256
RouteCounty Highway 979
Coordinates36.46138, -87.11712
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.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating55 US tons
Inventory rating41.1 US tons

Structure

MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length297 ft (90.5 m)
Longest span116 ft (35.4 m)
Deck width32 ft (9.8 m)
Roadway width29 ft (8.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic326 (2021)
Projected traffic522 by 2042
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Nfa 979 (sa 7401) over I24 built?

It was built in 1973, making it 52 years old in 2025.

What condition is Nfa 979 (sa 7401) over I24 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 March 2024.

How much traffic does Nfa 979 (sa 7401) over I24 carry?

About 326 vehicles per day (2021 count), of which roughly 3% are trucks.

How long is Nfa 979 (sa 7401) over I24?

The structure is 297 ft (90.5 m) long with a longest span of 116 ft (35.4 m) and a deck 32 ft wide.

Who owns Nfa 979 (sa 7401) over I24?

It is owned by the State Highway Agency.